Chemistry Flashcards

Question

Around how many elements are essential in the human body?

Answer 1

Smallest part of an elements which retains the characteristics of that element.

Answer 2

1) all matter is made up of atoms 2) all atoms of an element are similar to each other 3) atoms of different elements can combine to form compounds 4) atoms cannot be created or destroyed in chemical reactions

Answer 3

Scanning tunnelling microscope

Answer 4

Thomson in 1897

Answer 5

Thomson applied electricity to a glass tube producing cathode rays. The rays were attracted to a positively charged electrode meaning the rays must be negatively charged.

Answer 6

A random distribution of electrons within a positive cloud.

Answer 7

Rutherford 1911

Answer 8

By aiming positively charged particles at a thin sheet of gold. Results showed most carried on straight but occasionally some were deflected meaning atoms must have a small positive centre (nucleus)

Answer 9

One-twelfth of the mass of carbon 12

Answer 10

The number of protons (also number of electrons in a neutral atom)

Answer 11

The number of protons and neutrons

Answer 12

An atom of the same element which has a different amount of neutrons

Answer 13

The weighted mean mass of an atom of an element compared to 1/12th of the mass of an atom of carbon-12 (1 amu)

Answer 14

The mass of an atom of an isotope compared to 1/12th of the mass of an atom of carbon-12

Answer 15

It is the mean mass of a molecule compared to 1/12th of the mass of an atom of carbon-12

Answer 16

Percentage abundance and isotopic mass of each isotope

Answer 17

Percentage abundance and isotopic mass of each isotope E.g. Mg-24 at 79% Mg-25 at 10% and Mg-26 at 11% (24x79)+(25x10)+(26x11) ———————————— 100

Answer 18

Add together all the relative atomic masses of the atoms in the molecule

Answer 19

An electricity charged atom

Answer 20

Positive (cations)

Answer 21

Negative (anions)

Answer 22

Cr2O7 (2-)

Answer 23

Iodine, bromine, chlorine, fluorine, oxygen, nitrogen and hydrogen

Answer 24

Each electron shell

Answer 25

An electron sub-shell

Answer 26

S- P- D- F-

Answer 27

Dumbell shaped

Answer 28

5 (only from shell 3 onwards)

Answer 29

7 (from shell 4 onwards)

Answer 30

To minimise the repulsion between electrons

Answer 31

The energy needed to remove one electron from each atom in one mole of gaseous atoms to form one mole of gaseous 1+ ions

Answer 32

KJ per mole

Answer 33

Divide masses by relative atomic mass (to find moles) Divide each number by the smallest one These numbers show the ratio required

Answer 34

The amount of substance that contains 6.022x10(23) particles

Answer 35

6.022x10(23) (the same as the number of particles in each mole of carbon 12)

Answer 36

It’s relative atomic mass turned into grams

Answer 37

Mass divide by formula mass

Answer 38

Moles multiplied by formula mass

Answer 39

Mass divided by moles

Answer 40

The percentage by mass of each element present in a compound

Answer 41

Multiple relative atomic mass by number of atoms Divide by molecular mass of compound Multiple by 100

Answer 42

The actual number of atoms of each element in a molecule.

Answer 43

The simplest whole number ratio of atoms or ions of each element in a compound

Answer 44

Find empirical formula Divide actual mass by empirical formula mass

Answer 45

A mixture of solute and solvent particles

Answer 46

Amount of solute in a given amount of solution

Answer 47

An expression of concentration 1M = 1 mole of substance in 1dm(3) of its solution

Answer 48

Number of moles divided by volume

Answer 49

The volume per mole of gas molecules at a stated temperature and pressure

Answer 50

Divide by 1000

Answer 51

Number of moles of gas x 24

Answer 52

Volume of gas (dm3) —————————— 24

Answer 53

Shows how much product is obtained compared to the maximum possible mass

Answer 54

The percentage of atoms in reactants that form the desired product

Answer 55

The maximum amount of product that could be formed

Answer 56

Reaction may not have gone to completion Other side reactions may have taken place Purification of the product may result in some loss of product Some product may be left behind in apparatus Raw materials may not be pure

Answer 57

1) find moles of product 2) find ratio of moles of product to reactant Actual yield —————— x 100 Theoretical yield

Answer 58

Any reactant that is not in excess. Meaning the reacting will stop as soon as this is used up.

Answer 59

Used the balanced equation to see which reactant is used up quicker

Answer 60

The mass of useful product ————————————x 100 Total mass of all products

Answer 61

Reduce energy use Reduce costs Conserve raw materials Reduce waste Reduce pollution

Answer 62

To calculate the concentration of an unknown

Answer 63

1) calculate the volume, concentration and moles of the known substance 2) use the balance equation to work out mole ratio 3) use the mole ratio to work out the moles of the unknown 4) use the moles and volume of the unknown to finally workout the concentration

Answer 64

Finding the concentration of a solution by measuring the volume of a solution that will react with a known volume of standard solution

Answer 65

Initial conc. x initial vol. = new conc. x new vol This is then rearranged as required

Answer 66

A chemical solution containing the maximum concentration of a solute dissolved in the solvent at a particular temperature. No more solute will dissolve.

Answer 67

A solution that contains a higher that saturation concentration of solute. Any slight disturbance causes crystallisation of excess solute

Answer 68

A chemical property referring to the ability for a given substance to dissolve in a solvent

Answer 69

Insoluble solid that forms during a chemical reaction and separates out in solution

Answer 70

First silver nitrate: white precipitate Then dilute ammonia: precipitate disappears Then concentrated ammonia: N/A

Answer 71

First silver nitrate: cream precipitate Then dilute ammonia: precipitate remains Then concentrated ammonia: precipitate disappears

Answer 72

First silver nitrate: yellow precipitate Then dilute ammonia: precipitate remains Then concentrated ammonia: precipitate remains

Answer 73

Add dilute HCl acid to sample If effervescence observed carbonate is likely Transfer gas to limewater, if cloudy CO2 is present

Answer 74

Add barium chloride to sample. If present white barium sulfate precipitate will form

Answer 75

Ionic Covalent Dative/co-ordinate covalent Metallic

Answer 76

Van der Waals’ forces Dipole-dipole interaction Hydrogen bonds

Answer 77

An electrostatic force of attraction between positive and negative ions, usually between a metal and a non-metal

Answer 78

Each ion attracts oppositely charged ions in all directions. Resulting in a giant ionic lattice structure containing billions of atoms

Answer 79

Most are solids at room temperature as there is insufficient energy to overcome the strong electrostatic forces of attraction so most have high melting and boiling points the greater the ionic charge the higher the point The larger the ion the lower the point as weaker bonds due to being spread over a large surface

Answer 80

Most soluble in polar solvents such as water. Ionic lattice is broken down and solvent molecules surround the ions. The stronger the lattice the less soluble to compound.

Answer 81

Can conduct electricity it only if charged ions can move. So solids cannot but molten/ dissolved compounds can.

Answer 82

Strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms. Occurs in non metals elements, non metal compounds and poly atomic ions

Answer 83

A few atoms held together by covalent bonds

Answer 84

Contain many atoms, each joined to adjacent atoms by covalent bonds. Usually arranged into giant regular lattices

Answer 85

Low melting and boiling points as less energy needed to break weak intermolecular forces (not strong covalent bond)

Answer 86

They can either be polar or non-polar. Polar molecules dissolve in polar solvents. Non-polar molecules dissolve in non-polar solvents

Answer 87

Do not conduct electricity as they do not have any free electrons or an overall electric charge

Answer 88

A different form of the same element in the same state. E.g. graphite and diamond

Answer 89

High melting and boiling points due to presence of strong covalent bonds in the structures

Answer 90

Depends if there are any delocalised electrons. E.g. graphite will conduct but diamond will not

Answer 91

They are not soluble as covalent bonds in the lattices are too strong to be broken

Answer 92

Electrostatic interaction between positive metal ions and delocalised electrons. The atoms are ionised and these ions occupy fixed positions in the lattice. Outer shell electrons are delocalised and shared between all atoms within the structure

Answer 93

Most conduct electricity in solid and liquid state. The delocalised electrons can move through the structure carrying a charge

Answer 94

Most metals have high melting and boiling points. Depends upon the strength of metallic bonds within the structure. High temperatures are needed to overcome strong electrostatic attraction between the cations and electrons. The higher the ionic charge of the metal the higher the melting point

Answer 95

Metals do not dissolve. Any interaction between polar solvents and changed in metallic lattice would lead to reaction rather than dissolving

Answer 96

Metals can be hammered and pressed into shape as atoms can roll over each other into new positions without the bonds breaking Metals can be drawn out into a wire again due to atoms rolling over each other

Answer 97

Mixtures containing metals. Not a compound as there can be different ratios of metals. They can modify a metals properties e.g. ions may be different sizes to stop layers moving past each other making it harder

Answer 98

Very similar to a covalent bond apart from both electrons involved in the bond are from the same atom.

Answer 99

The forces that hold atoms together within a molecule

Answer 100

Forces that exist between molecules

Answer 101

Induced dipole-dipole interactions (London/ Van der Waals) Permanent dipole/dipole interactions Hydrogen bonding

Answer 102

Intermolecular

Answer 103

A measure of the tendency of an atom to attract a bonding pair of electrons in a covalent bond. The greater the electronegativity the greater the attraction.

Answer 104

The Pauling scale to measure electronegativity of atoms

Answer 105

As the radius increases the bonding pair of electrons becomes further from the nucleus. They are therefore less attracted to the nucleus. So the greater the radius the lower the electronegativity.

Answer 106

Full energy levels of electrons shield the electrons in the bond from the increased attraction of the greater nuclear charge, reducing electronegativity

Answer 107

The electronegativity in both atoms of the covalent bond is identical so the electrons are equally attracted to them both. This cause symmetrical distribution of electron density around the two atoms.

Answer 108

When a covalent bond is formed by atoms with different electronegativities.

Answer 109

When there is asymmetrical distribution of electron density because one atom attracts the electrons more strongly this created an imbalance in the charges in the bond.

Answer 110

Delta positive and delta negative

Answer 111

If the polar bonds are arranged symmetrically, the partial charges cancel each other

Answer 112

If polar bond are asymmetrically arranged, the partial charges do not cancel each other out

Answer 113

Resulting weak forces of attraction between the small charges (temporary dipoles)

Answer 114

As the radius increases the electrons are less attracted to the nucleus so temporary dipoles are easier to induce

Answer 115

The more points of contact between the molecules the stronger the van der Waals forces

Answer 116

If molecules contain bonds with a permanent dipole the molecules may align so there is electrostatic attraction between the opposite charges on neighbouring molecules

Answer 117

A special type of permanent dipole-dipole bond interaction found between molecules containing: An electronegative atom with a lone pair of electrons e.g. oxygen, nitrogen, fluorine A hydrogen atom attached to the electronegative atom. The hydrogen bond acts between the hydrogen atom in one molecule and the lone pair of electrons in an electronegative atom of another molecule

Answer 118

Hydrogen Permanent dipole/dipole Van der Waals

Answer 119

Hydrogen bonds hold water molecules further apart in an open lattice structure when solid. So the water molecules in ice are further apart than in water

Answer 120

The total number of electron pairs around the central atom. Lone pairs repel more than bonding pairs.

Answer 121

The distance between the nuclei of two bonded atoms

Answer 122

The angle between two covalent bonds

Answer 123

The electron pairs around the central atom determine the shape of the molecule or ion The electrons pairs repel electrons each other so they are arranged as far apart as possible The arrangement of electron pairs minimise repulsion and therefore holds the bonded atoms in a definite shape Different number of electron pairs result in different shapes

Answer 124

Four bonded pairs repel each other as far as possible Bond angle of 109.5 e.g. methane

Answer 125

Contains 3 bonded pairs and one lone pair of electrons. Since the lone pairs repel more strongly than bonded pairs this means the bonded angles are closer together decreasing the bond angle Bond angle of 107 e.g. ammonia

Answer 126

Two bonded pairs and two lone pairs. The lone pairs repel more strongly creating the V-shape Bond angle of 104.5 E.g. water

Answer 127

Molecules that contain 2 bonding regions but not lone pairs Bond angle 180 E.g. CO2

Answer 128

Contains 3 bonded pairs and no lone pairs. Bond angles of 120 E.g. boron trifluoride

Answer 129

6 bonded pairs and no lone pairs Bond angle of 90 E.g. SF6

Answer 130

1) work out number of valance electrons of central atom 2) take into account any charges for ions 3) work out the number of covalent bonds made by the central atom 4) work out amount of electron pairs 5) determine the shape

Answer 131

5 bonded pairs and no lone pairs 2 x 90 3 x 120

Answer 132

Heat taken in, in a chemical reaction. The products have more energy than the reactants.

Answer 133

Heat given out, in a chemical reaction. The products have less energy than the reactants.

Answer 134

Energy needed to start a reaction. Activation energy used to break bonds so reaction can take place and new bonds can form.

Answer 135

The energy it takes to break one mole of a specific bond type in gas form.

Answer 136

Draw out bonds Use average bond enthalpy table Sum of bond enthalpies of bonds broken - sum of bond enthalpies of bonds made. - figure shows exothermic + figures shows endothermic

Answer 137

Doing an experiment in set conditions so you can measure temperature change. Allows you to measure enthalpy change directly. Gives true value rather than approximate. Mass of surroundings x specific heat capacity of surrounding x change in temperature of surroundings. Then usually scale up to one mole. Surroundings usually = water

Answer 138

The energy required to raise the temperature of 1g of a substance by 1C. Units: JK-1g-1 Specific heat capacity of water: 4.18

Answer 139

Overall energy change at constant pressure, if the conditions are standard conditions we call it the standard enthalpy of reaction

Answer 140

Pressure of 100kPa Temperature of 298K (25°C) Concentration of 1M, for reactions with aqueous solutions The standard state is the physical state of a substance under standard conditions. E.g. H20 is liquid

Answer 141

The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states.

Answer 142

The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states. Since it is only one mole there may be fractions of other substances in the equation.

Answer 143

The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.

Answer 144

If a reaction can take place by more than one route and the initial and final concentrations are the same, the total enthalpy change is the same.

Answer 145

Add if arrow going correct way Subtract if arrow going wrong way Combustion reactants-products Formation products-reactants

Answer 146

A measure of disorder Solids lower Gases higher

Answer 147

Change in concentration (mol dm-3) —————————————— Time for change to occur (seconds) For the average time For more specific use a graph and use a tangent to work out the gradient

Answer 148

Increase temperature Increase reactant concentration Increase reactant pressure Increase surface area e.g. use a powder Adding a catalyst

Answer 149

1) particles have to collide 2) have collision energy equal to or greater than the reactions activation energy 3) collide with proper orientation

Answer 150

Increases the rate of reaction without being consumed. The reaction follows a different reaction route, usually with a lower activation energy.

Answer 151

Homogeneous catalyst- reactant and catalyst in same states Heterogeneous catalysts- reactant and catalyst in different states

Answer 152

Total area under the curve= total number of molecules in the system Area under the curve and to the right of activation energy= number of molecules with sufficient energetic to react

Answer 153

No particles have 0 energy Most particles have intermediate energy A few particles have high energy The average energy is not the same as the most probable energy

Answer 154

When reversible reactions reach a balance point, where the amount of reactants and the amount of products formed remains constants.

Answer 155

The forward and backwards reactions continue at equal rates so the concentrations of reactants and products do not change. On a molecular scale there is constant change, but on the macroscopic scale nothing appears to be happening. Required conditions: 1) must be a reversible reaction 2) must be in a closed container

Answer 156

If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium moves to counteract the change.

Answer 157

1) pressure 2) concentration 3) temperature

Answer 158

If you increase the concentration of the reactants, the equilibrium will shift to the right If you decreases the concentration of the reactants, the equilibrium will shift to the left If a product is removed the equilibrium would shift to the right. If the product was continually removed the reaction would eventually turn into an irreversible reaction.

Answer 159

Only applies to reactions involving gases If pressure is increased the equilibrium will move in the direction on the least molecules to try to reduce the pressure. If pressure is decrease the equilibrium will move in the direction on the most molecules to try to increase the pressure. If there are the same number of molecules on each side, changing the pressure would have no effect on the position of equilibrium

Answer 160

Depends if the forward reaction is exothermic to endothermic If temperature is increased the equilibrium will try to cool down. The equilibrium will move towards the endothermic reaction. If temperature is decreased the equilibrium will try to heat up. The equilibrium will move towards the exothermic reaction.

Answer 161

They have no influence on the position of equilibrium but help it to be reached quicker

Answer 162

Important as can a determine conditions for highest yield but need to consider: Low temperature and pressure means slow rate of reaction High temperature and pressure means expensive to run and build suitable equipment So most use a compromise set of conditions

Answer 163

Kc Different for every reaction The size of Kc shows how far a chemical reaction has gone. Indicates the position of equilibrium

Answer 164

If \>1 the reaction is product favoured so equilibrium lies to the right If \<1 the reaction is reactant favoured so equilibrium lies to the right When Kc is 10^10 they are regarded as gone to completion, so no longer reversible When Kc is 10^-10 the reaction is regarded as not taking place

Answer 165

aA + bB cC + dD Kc = [C]^c [D]^d ——————- [A]^a [B]^b So equilibrium concentration of products divided by reactants, raised to the power of their stoichiometry

Answer 166

Find out the initial amounts, changes and therefore equilibrium moles Find concentrations, so moles/volume Use Kc expression

Answer 167

Concerned with compounds of carbon

Answer 168

Carbon, hydrogen and sometimes oxygen and other non-metallic elements

Answer 169

Carbon Hydrogen Then any others

Answer 170

Can form an infinite number of compounds Can make up to four covalent bonds (single, double or triple) Can form covalently linked C-C chains of unlimited length Forming a variety of branches, linear and cyclic compounds

Answer 171

Length Branching Double bind positions (if present) Presence of rings

Answer 172

A group of organic chemical compounds, that have similar structure and properties, the structure only differs by the number of CH2 units in the main carbon chain

Answer 173

4 single bonds 2 double bonds 2 single bonds and 1 double bond 1 single bond and 1 triple bond

Answer 174

C(n)H(2n+2)

Answer 175

Ane (methane, ethane, propane)

Answer 176

Hydrocarbons Only have single C-C bonds Saturated (have maximum number of hydrogens)

Answer 177

The pre-fix of the number of carbons in chains followed by ‘ane’

Answer 178

1) identify the longest carbon chain in any direction 2) number the carbon chain (make sure the branched group has the lowest number possible) 3) find the name of of longest chain e.g. octane 4) find the name of the branched group e.g. meth and add ‘yl’ 5) find the number of the carbon the branch group is on 6) e.g. 2-methyloctane 7) write in alphabetical order if more than one branch group

Answer 179

1) meth 2) eth 3) prop 4) but 5) pent 6) hex 7) hept 8) oct 9) non 10) dec

Answer 180

Alkyl group

Answer 181

Where one or more hydrogen from an alkane is replaced by a halogen Name added to alkane with number of branch

Answer 182

The longer the carbon chain the higher the boiling point as the chain increases so does the number of electrons in the molecules so the van der Waals forces are stronger Straight alkanes have higher boiling points that branches alkanes as the molecules can lie closer together

Answer 183

End in ‘ene’ Have at least one C-C double bond Unsaturated (doesn’t have maximum number of hydrogen atoms)

Answer 184

End in ‘yne’ Contain at least one C-C triple bond Unsaturated

Answer 185

1) The longest carbon chain must contain the double/triple bond 2) number carbon chain from the end closest to double/triple bond 3) add number to name of the carbon the double bond is on 4) add any groups e.g. methyl

Answer 186

Use bromine water Becomes colourless if alkene as bromine reacts with C-C double bond Stays red/brown if alkane as no double bond to react with

Answer 187

A reaction in which hydrogen atoms add to each of the carbon atoms in a double bond of an alkene turning it into an alkane A metal catalyst is used

Answer 188

A ring of carbon atoms with two hydrogen atoms attached to each carbon Formula of C(n)H(2n) They are saturated Add cyclo to the name

Answer 189

Group of aromatic hydrocarbons with a molecular structure containing one or more flat sets of six carbon atoms. Each carbon forms a single covalent bond to the carbons either side and to one hydrogen atom. The final unpaired electron on each carbon is located in the P-orbital that sticks out above and below the plane of the ring. This forms a ring of delocalised electrons. Unsaturated cyclic hydrocarbons Benzene is an example

Answer 190

Molecular formula of C6H6 Ring structure Groups can be added off of benzene

Answer 191

Shows the arrangement of atoms and the bonds

Answer 192

Compounds with the same molecular formula but the atoms are arranged differently which can lead to differences in physical and chemical properties

Answer 193

Chain length isomers Position isomers Functional group isomers

Answer 194

Geometric isomers Optical isomers

Answer 195

Carbon atoms in skeleton arranged differently

Answer 196

Have the same functional groups but attached to different points of the main chain

Answer 197

Have different functional groups E.g. alkane, alkene, alcohol, ether

Answer 198

Have the same structural formula but different in the arrangement of bonds

Answer 199

Differ in the arrangement of the groups attached to the carbons in double bonds

Answer 200

End to end overlap of atomic orbitals All single bonds

Answer 201

When the lobe of one atomic orbital overlaps another Double bonds have a Pi bond as wells as a sigma bond

Answer 202

If the atoms other than hydrogen are all on the same side of the chain they are cis isomers If the atoms other than hydrogen are different sides of the chain they are trans isomers

Answer 203

Hard to figure out which side of which if lots of hydrogens have been substituted for different groups E.g. one side may have carbon and chlorine and the other fluorine and bromine

Answer 204

Used to identify stereoisomers that cannot be defined at cis or trans Isomers identified as either E or Z The higher the atomic number the higher the priority E corresponds to trans form (opposite sides) Z corresponds to cis form (same sides)

Answer 205

Have the same molecular and structural formula but cannot be superimposed as they are mirror images Can occur when an asymmetric carbon (bonded to four different groups) is present so it forms a chiral centre of the molecule

Answer 206

When a carbon atoms is bonded to four different groups

Answer 207

Can rotate the plane of polarised light. Clockwise - positive enantiomer (D form) Anti-clockwise- negative enantiomer (L form) No effect- racemic/racemate

Answer 208

Assign priority to all groups from chiral centre by atomic number View molecule so lowest priority is away from observer Arrow is drawn around in order of priority groups If arrow is clockwise it is R form If arrow is anti-clockwise it is S form

Answer 209

Free radical substitution

Answer 210

Electrophilic addition

Answer 211

1) initiation 2) propagation 3) termination

Answer 212

UV light absorbed by halogen molecule to provide energy to break the bond. One electron goes to each halogen and forms two free radicals (homolytic fission)

Answer 213

Single bond breaks, one electron to each molecule. Shown by a curly half arrow head. Forms two products that are the same

Answer 214

Breaking of bonds. One atoms gains both electrons. So atom is now negatively charged and other is positively charged. Two different products

Answer 215

A highly reactive species with a single unpaired electron. Electron is represented by a dot.

Answer 216

A halogen radical reacts with a methane molecule. This removed hydrogen from the methane and forms a methyl radical and hydrogen chloride. The methyl radical can then bond with a halogen molecule forming another halogen radical and halogenmethane. During this process the total number of radicals remains the same.

Answer 217

Total number of free radicals decreases. Free radicals can join together to create stable molecules. Methyl to halogen Halogen to halogen Methyl to methyl

Answer 218

Hard to separate the mixture of products formed

Answer 219

Halogenoalkane molecules where all the hydrogen atoms have been replaced by fluorine or chlorine.

Answer 220

Destroy the ozone layer (O3) due to free radical substitution

Answer 221

Electrophilic addition. As the double bond is an area of high negative charge making it very reactive.UV light is not needed.

Answer 222

Electron pair acceptor. They accept a pair of electrons to form a covalent bond. They are electron deficient. Represented as E+.

Answer 223

Electron pair donator. They donate a pair of electrons to form a covalent bond. They can be represented by Nu:

Answer 224

The double bond in the alkene is electron dense (negatively charged). The electrophile is attracted to this. The electrophile breaks down and undergoes heterolytic fission so both the electrons go to the atom not attaching to the double bond. Finally the atom that accepted the electrons bonds with the other carbon to form a dative covalent bond.

Answer 225

Homologous series of organic compounds with the general formula CnH2n+1OH Names end in ol Functional group is OH

Answer 226

Name of length of carbon chain with suffix -ol If there are 3 or more carbons positional isomerism can be displayed The carbon number the OH is attached to is written before -ol

Answer 227

Much higher boiling point than alkanes Boiling point increases as carbon chain length increases Most are liquid at room temperature

Answer 228

The electronegative oxygen atom in the hydroxyl group means alcohols are polar so can take part in hydrogen bonding meaning the boiling point will be higher than that of an alkane Hydrogen bonding also means alcohols can mix with water

Answer 229

Hydration of an alkene add water to alkene in form of steam with a phosphoric acid catalyst. Temperature must be 570K and pressure 60-70 atm Fermentation Glucose + yeast —\> ethanol + carbon dioxide Anaerobic conditions Temperature 25-35c Yeast dies when ethanol concentration reaches around 15% Slow process

Answer 230

Renewable resources used Less energy used

Answer 231

High yield of ethanol Atom economy of 100% Fast reaction Can be done continuously

Answer 232

Primary: have one R group attached to the carbon to which the OH group is attached Secondary: have two R groups attached to the carbon to which the OH group is attached Tertiary: have two R groups attached to the carbon to which the OH group is attached

Answer 233

Carbonyl group C=O

Answer 234

Carbonyl group at the end is an aldehyde. So it has at least one hydrogen attached to it Carbonyl group in the middle is a ketone so has two carbons attached to it

Answer 235

Named using carbon chain length and then the suffix -al Carbons numbered starting with carbonyl group as 1

Answer 236

Using length of carbon chain and suffix -one Carbon number of carbonyl group placed before suffix

Answer 237

Polar Positive charge on the carbon makes it open to attacked by nucleophiles Aldehydes and ketones can be reduced, forming alcohol Aldehydes can be oxidised to carboxylic acids

Answer 238

Small ones are soluble in water due to hydrogen bonding between a lone pair on the oxygen of the carbonyl group and the hydrogen of water As size increases solubility decreases due to interference in hydrogen bonding by the hydrocarbon tails Have mid range boiling points as have van der Waals forces AND the polar carbonyl group means dipole-dipole interactions are present

Answer 239

Alkanes have the lowest as only van der Waals forces are present Aldehydes & ketones are higher as they also have dipole-dipole interactions as the carbonyl group is polar Alcohols are higher still as they also have hydrogen bonding Carboxylic acids are highest as they have more hydrogen bonds

Answer 240

Primary alcohols can be oxidised by an oxidising agent such as an aqueous solution of acidified potassium dichromate which changes colour from orange to green. Water is also produced in the reaction.

Answer 241

Secondary alcohols can be oxidised by an oxidising agent such as an aqueous solution of acidified potassium dichromate. Water is also produced

Answer 242

The lack of hydrogen atoms on the carbon atom to which the hydroxyl group of attached

Answer 243

Tollens’ reagent: Sodium hydroxide + aqueous silver nitrate. This forms a brown precipitate of silver nitrate (Ag2O). Aqueous ammonia is added until precipitate dissolves and a solution of the silver amine [Ag(NH3)2]+ is formed. A silver colour is formed if aldehydes are present No colour change if ketone Benedict’s solution: An alkaline solution containing copper ions. When heated with an aldehyde the Cu2+ complex ion acts as an oxidising agent and the blue turns to red No colour change if ketone

Answer 244

Carboxyl group (COOH) attached to terminal carbon

Answer 245

Using length of carbon chain and suffix -oic acid

Answer 246

Polar due to presence of two electronegative oxygen atoms and a partially charged carbon and hydrogen atom Can take part in: Neutralisation- carboxylic acid loses a proton to from a carboxylate salt Nucleophillic substitution- partially positive carbon is attacked by nucleophile resulting in substitution of OH group Esterification- reaction with an alcohol for form an ester

Answer 247

Solubility depends on side. The smaller the compound the higher the solubility. Carboxylic acids are higher due to more hydrogen bonds present

Answer 248

Primary alcohols are reacted with an excess of oxidised agent and refluxed. Primary alcohol—\>aldehyde —\>carboxylic acid Reflux position is the condenser tube vertical. The condenser tube is continuously surrounded by cold water. As aldehyde is produced it evaporates but the cold water then cools it back to a liquid so it can go back to undergo second oxidisation Reflux definition: the continuous evaporation and condensation of a volatile substance without loss of any product

Answer 249

-COO- Carbon double bonded to one oxygen and single bonded to another oxygen

Answer 250

Esterification: When alcohol is warmed with a carboxylic acid in the presence of an acid catalyst. A water molecule is removed Concentrated sulfuric acid is often used as the catalyst The O-H bond of alcohol is broken and water formed with the OH from the carboxylic acid group and the H in the alcohol group Carboxylic acid + alcohol -\> ester + water

Answer 251

First part from the alcohol used with -yl e.g ethyl Second part from carboxylic acid used with -anoate e.g. ethanoate X-yl X-anoate

Answer 252

Chemical reaction using water to break down bonds of a substance Esters can be hydrolysed by refluxing with either an acid or alkali With an acid it reverses the ester back to an alcohol and carboxylic acid With an alkali it hydrolysed to an alcohol and sodium salt of the acid

Answer 253

Nitrogen containing organic compounds derived from ammonia where one or more of the hydrogen atoms has been replaced by an alkyl or aryl group

Answer 254

Primary: where one hydrogen from ammonia is substituted with carbon Secondary: where two hydrogens from ammonia are substituted Tertiary: where all three hydrogen atoms are substituted Quaternary: where four carbons are attached to the nitrogen, using ammonia’s lone pair of electrons

Answer 255

Use the length of the carbon chain and use suffix -amine E.g. methylamine If other functional groups are present then the amino- prefix is used E.g. 2-aminoethanoic acid

Answer 256

Solubility: shorted chains are soluble in water as the lone pair of electrons in the nitrogen atom allows them to form hydrogen bonds with water molecules Larger amines are less soluble as the larger R groups interfere with hydrogen bonds Boiling points: primary amines have higher boiling points that alkanes as they can form hydrogen bonds . Secondary amines having slightly lower boiling points as the nitrogen forming the hydrogen bond is in the middle of the chain and this slightly reduces the strength of the dipole Tertiary amines have even lower boiling points

Answer 257

Products of reactions between carboxylic acids and amines An amide and water is produced Contain functional group CONH Amino acids contain both amine and carboxylic acid functional groups. They can react together to form an amide link (peptide bond)

Answer 258

Hydrochloric acid: HCL Nitric acid: HNO3 Ethanoic acid: CH3COOH Sulfuric acid: H2SO4

Answer 259

Acids dissociate and release H+ ions in an aqueous solution Alkalis dissociate and release OH- ions in an aqueous solution

Answer 260

An acid plus a base equals salt and water H+ + OH- ---\> H2O For example: NaOH + HCl ---\> NaCl + H2O

Answer 261

Emphasises the role of the proton transfer An acid is a substance that can donate a proton A base is a substance that can accept a proton

Answer 262

H3O+ The active ingredient in any acicid solution Usually shortened to H+

Answer 263

It contains two species that the transfer of a proton can interconvert

Answer 264

It can act as both an acid and a base Such as water

Answer 265

The total number of hydrogen ions in the acid that can be replaced per molecule

Answer 266

They fully dissociated in water

Answer 267

They only partially dissociate in water

Answer 268

A high number of moles of acid in 1dm3 of solution

Answer 269

A low number of moles of acid in 1dm3 of solution

Answer 270

pH = -log10 [H+] The square brackets mean concentration in mol dm-3 of hydrogen ions If diprotic or triprotic, then multiple concentrations by two or three as they will contain more moles of hydrogen per molecule

Answer 271

10^-pH Eg pH 8.75 is 10^-8.75 = 1.78 x 10^-9 mol dm^-3

Answer 272

Kw= [H+][OH-] Since the H and OH in water are equal, it can also be written as: Kw=[H+]^2

Answer 273

With temperature

Answer 274

Kw = [H+]^2 [H+] = square root of Kw Then calculate pH as normal, -log[H+]

Answer 275

An aqueous solution that resists change in pH upon the addition of acid or base

Answer 276

Mix a large volume of weak acid/base with its conjugate base/acid

Answer 277

When a strong base is added, the acid present in the buffer neutralises the hydroxide ions When a strong acid is added, the base present in the buffer neutralises the hydronium ions

Answer 278

Three cyclohexane rings One cyclopentane ring 17 labelled carbons

Answer 279

Fat-soluble Derived from fatty acid biosynthesis have a hydrophobic core Some functional groups may impart polarity/ water solubility

Answer 280

Gonane Cyclopentanoperhydrophenanthrene

Answer 281

6 8 9 10 13 14

Answer 282

64 theoretically but only a few occur in nature

Answer 283

Corticosteroids Sex hormones

Answer 284

Adrenal cortex

Answer 285

Glucocorticoids Mineralcorticoids

Answer 286

Androgens Progestogens Estrogens

Answer 287

Glucoreceptors

Answer 288

Metal containing receptors

Answer 289

Cholesterol

Answer 290

Binding of hormones to receptors causes configuration changes in the receptor which then has a regulatory effect on the DNA element

Answer 291

Bind to ion channels and GCPRs Can have a direct effect on cell membrane

Answer 292

Glucocorticoid

Answer 293

Rheumatic problems Skin disease Severe allergy Asthma COPD croup Brain swelling Covid-19

Answer 294

It affects global receptors It is not specific to one area So it can cause side effects

Answer 295

C22H29FO5 Usual steroid structure but with: - fluorinated at position 9 - hydroxy groups at positions 11, 17 and 21 - methyl group at position 16 - carbonyl (oxo) groups at positions 3 and 20

Answer 296

1) enters the cell 2) binds to an intracellular receptor 3) heat-shock protein is hydrolysed, and releases activated steroid-receptor complex 4) steroid-receptor complex is transported into the nucleus 5) binds to DNA 6) modifies DNA glucocorticoid-responsive elements and transcription factors 7) this alters the transcription of target genes in DNA into mRNA 8) mRNA leaves the nucleus 9) mRNA directs the synthesis of new proteins on cytoplasmic ribosomes 10) these proteins are released from the cell and elicit a biological response

Answer 297

Reduces inflammation. An increase in the production of anti-inflammatory compounds such as annexin-1, SLP1, MOP-1, and nitric oxide synthase

Answer 298

Immunosuppressive. Reduces the production of pro-inflammatory compounds, including cytokines, chemokines, adhesion molecules. Also, reduce the production of pro-inflammatory enzymes such as A2 and cyclooxygenase

Answer 299

Building things up, such as muscle Regulate several genes associated with virilisation (development of male characteristics)

Answer 300

The androgenic steroids maintain skeletal integrity in males, whereas, in females, they develop the bones but do not maintain them

Answer 301

Testosterone Oxandrolone

Answer 302

C19H28O2 It contains a ketone functional group at position 3 It contains a hydroxyl group at position 17

Answer 303

Androgenic : anabolic Testosterone 1:1 Oxandrolone 1:3-13 So oxandrolone has a much greater anabolic effect with less androgenic effects

Answer 304

Physiological issues Testicular shrinkage Heart attack Stroke High BP Male pattern baldness (in males and females) Breast growth in males Breast shrinkage in females

Answer 305

They can bind with other lipids to produce a liquid ordered membrane. The right levels is crucial.

Answer 306

Immunoglobulins Immunostimulants Immunosuppressants

Answer 307

Antibodies isolated from patients to give to others Usually in the form of IgM and IgG

Answer 308

Hard to modify

Answer 309

Vaccines Interferon (such as Pegasys) Interleukins (aldesleukin)

Answer 310

Cytokines- proteins Have many different effects but usually either down-regulate or activate certain pathways

Answer 311

Proteins produced in response to an immune response and upregulate the response

Answer 312

Aldesleukin IL-2 Used for cancer cells by interfering with growth. It stimulates the immune system By encouraging the growth of killer T cells and other cells that attack cancer

Answer 313

Reduce inflammation Reduce symptoms of autoimmune diseases Reduce allergic reaction Reduce transplant rejection

Answer 314

Calcineurin inhibitors (cyclosporin, tacrolimus) IL inhibitors (anakinra, tocilizumab) TNFa inhibitors (adalimumab, infliximab) Methotrexate Omalizumab (anti IgE) Azathioprine NSAIDs

Answer 315

Forms complexes with cyclophilin to block phosphatase activity of calcineurin. This decreases the production of inflammatory cytokines by T cells.

Answer 316

Inhibit cyclooxygenase that makes prostaglandins

Answer 317

Acts against rapidly dividing cells so can be used for cancer Bone marrow is also rapidly dividing, so it becomes an immunosuppressant

Answer 318

Inhibits conversion of T4 to T3 to the hormone cannot enter the cell

Answer 319

Carbimazole is myelotoxic (toxic to bone marrow), so therefore, a reduction in WBC can occur

Answer 320

to covert to THF to make nucleic acids

Answer 321

Humans absorb DHF from the diet but bacteria need to synthesis their own so we can target this enzyme in this process

Answer 322

P-aminobenzoic acid + pteridine ---\> dihydropteroate ---\> DHF With the help of the enzyme dihydropteroate synthetase

Answer 323

Dihydrofolic acid

Answer 324

Tetrahydrofolic acid

Answer 325

In 1935 Prontosil was used, it was a prodrug that metabolised by breaking a double bond between two nitrogens to sulphanilamide

Answer 326

Inhibit dihydropteroate synthetase in bacteria The sulfonamide is structurally similar to the natural enzyme-substrate, p-aminobenzoic acid Competitive inhibitors and classed as bacteriostatic

Answer 327

Hydrogen bonds

Answer 328

Van der Waals interactions from benzene ring

Answer 329

ionic bonding

Answer 330

1) aromatic ring 2) sulfonamide group 3) p-substitution only 4) sulfonamide N must be 1° or 2° (either one or two hydrogens present) 5) p-amino group must be 1° (one hydrogen group present) 6) if amino R group is an acetyl group it can act as a prodrug 7) sulfonamide R group is the only variable

Answer 331

Changing the R group on the sulfonamide group

Answer 332

An amide group lowers the polarity of the sulfonamide and increases hydrophobic character as it cannot ionise but can then be hydrolysed into the active form. This allows the drug to cross the gut wall more easily

Answer 333

N-acetylation which increases hydrophobic character which reduces the aqueous solubility and can potentially lead to side effects so we need to try to increase the water solubility of the drug

Answer 334

We can change the R2 group so the sulfonamide N-H bond is more acidic. Converting sulfathiazole to sulfadiazine The pyrimidine ring of the sulfadiazine is more electron-withdrawing therefore making the negative ion formed more stable lowering the pKa of the sulfonamide N-H proton

Answer 335

Using a combination of drugs that inhibit different enzymes in the same biosynthesis pathway It allows lower, safer dose levels of each drug

Answer 336

Beta= size of ring Lactam= Cyclic amide

Answer 337

Inhibit an enzyme called transpeptidase which is needed for cell wall synthesis They are bacteriocidal Gram-positive are more susceptible The penicillin resembles the D-ala-D-ala residue (natural substrate), and the transpeptidase enzyme binds penicillin and catalyses C-N bond fission to give an acetyl enzyme that does not turn over

Answer 338

Two alanine amino acid residues in a dipeptide structure

Answer 339

Due to the strain of the four-membered ring A smaller bond angle than usual causes torsional strain meaning the molecules will more readily react to relieve the strain

Answer 340

1) amide group 2) carboxylic acid/carboxylate 3) B-lactam ring 4) B-lactam ring as a bicyclic 5) variation limited to side chain R

Answer 341

a standard nucleophilic acyl substitution reaction

Answer 342

limited range of activity Not orally active as it's sensitive to stomach acid Sensitive to beta-lactamases

Answer 343

Increase chemical stability for oral administration Increase resistance to B-lactamases Increase range of activity

Answer 344

Make the side-chain an electron-withdrawing group, drawing the electrons away from the carbonyl oxygen, making it less nucleophilic

Answer 345

Add steric Shields (bulky side chains) to stop penicillin from accessing the B-lactamase active site However, if they are too bulky, then it prevents penicillin from binding to the transpeptidase enzyme Give beta-lactamase inhibitors such as clavulanic acid

Answer 346

1) B-lactam ring 2) Carboxylic acid at position 4 is important for binding 3) Bicyclic ring important for increasing ring statin 4) stereochemistry is important

Answer 347

Blocks transglycosidation by providing a binding pocket for the biosynthetic building blocks and binds to the tail of the building blocks peptide chain Forms hydrogen bonds to the target and therefore acts as a receptor for the building block

Answer 348

Due to a mutation in a pentapeptide chain of cell wall building blocks where the terminal D-alanine is replaced by D-lactate

Chemistry Flashcards

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