What's in Medicine Flashcards by Harry McDonald

Define a base using the Bronsted-Lowry theory

A proton acceptor

How well did you know this?

Not at all

Perfectly

Describe the movement of an H⁺ ions during an acid-base reaction

From acid to base

How well did you know this?

Not at all

Perfectly

Explain how the Arrhenius definition and Bronsted-Lowry definition of a base agree with each other

The Arrhenius definition states that a base releases OH⁻ ions in solution. This agrees with the Bronsted-Lowry definition that bases accept protons (since OH⁻ accepts H⁺ ions) but, Arrhenius’ definition would mean that a substance could not be a base unless in solution.

How well did you know this?

Not at all

Perfectly

Name the product for the reaction between gaseous Hydrochloric acid and Ammonia

HCl (g) + NH₃ (g) → NH₄Cl (s)

Hydrochloric Acid + Ammonia → Ammonium Chloride

How well did you know this?

Not at all

Perfectly

Give the structure and type of intramolecular bonds for the bonding between ions of a metal and a non-metal

Ionic Bonding held by electrostatic attraction

Ionic Lattice Structure

How well did you know this?

Not at all

Perfectly

Name and describe the structure of the intramolecular forces between metallic elements

Structure : giant metallic lattice

Positive metal ions in a “sea” of delocalised electrons

How well did you know this?

Not at all

Perfectly

Sodium Ethoxide is a white ionic solid.
When added to water, the ethoxide ion reacts as given;
C₂H₅⁻ (aq) + H₂O (l) → C₂H₅OH (aq) + OH⁻ (aq)
This is an acid base reaction.
a) Identify the base and explain using the Bronsted-Lowrey theory
b) What is the role of water in this reaction? Explain how you know

a) C₂H₅O⁻ (ethoxide ion) is the base because it accepts a proton in order to become C₂H₅H
b) Water is acting as an acid in this reaction because it loses H⁺ t becme OH⁻

How well did you know this?

Not at all

Perfectly

What is the Bronsted-Lowrey definition of acids and bases?

Acids are proton donors

Bases are proton acceptors

How well did you know this?

Not at all

Perfectly

According to some acid-base theories, aluminium chloride (AlCl₃) is an acid.
Could AlCl₃ be an acid according to the Bronsted-Lowret theory? Explain your answer.

No, because it has no protons to donate

How well did you know this?

Not at all

Perfectly

In these reactions, say whether water is acting as an acid , a base or neither according to the Bronsted-Lowrey theory.

i) HNO₃ + H₂O → H₃O⁺ + NO₃⁻
ii) NH₃ + H₂O → NH₄⁺ + OH⁻

i) base

ii) acid

How well did you know this?

Not at all

Perfectly

Give the following physical properites for Ionically bonded substances

i) Melting and Boiling points
ii) Typical state at STP
iii) Electrical conductor when solid?
iv) Electrical conductor when liquid?
v) Is it water soluble?

i) High
ii) Solid
iii) No (ions are held firmly in place)
iv) Yes (ions are free to move)
v) Yes

How well did you know this?

Not at all

Perfectly

Give the following physical properites for simple molecular (covalently bonded) substances

i) Melting and Boiling points
ii) Typical state at STP
iii) Electrical conductor when solid?
iv) Electrical conductor when liquid?
v) Is it water soluble?

i) Low (have to overcome Van der Waals forces or hydrogen bonds, not covalent bonds)
ii) Sometimes solid, usually liquid or gas (water is lqiuid due to its Hydrogen bonds)
iii) No
iv) No
v) Depends on how polarised the molecule is

How well did you know this?

Not at all

Perfectly

Give the following physical properites for giant molecular (covalently bonded) substances

i) Melting and Boiling points
ii) Typical state at STP
iii) Electrical conductor when solid?
iv) Electrical conductor when liquid?
v) Is it water soluble?

i) High
ii) Solid
iii) No (except graphite)
iv) - (will generally sublime)
v) No

How well did you know this?

Not at all

Perfectly

Give the following physical properites for metallicaly bonded substances

i) Melting and Boiling points
ii) Typical state at STP
iii) Electrical conductor when solid?
iv) Electrical conductor when liquid?
v) Is it water soluble?

i) High
ii) Solid
iii) Yes (delocalised electrons)
iv) Yes (delocalised electrons)
v) No

How well did you know this?

Not at all

Perfectly

Explain why molceucles with the same number of electron densities around a central atom normally exhibit the same shape

Electrons have the same charge so areas of electron density repel eachother as far away from each other as possible

How well did you know this?

Not at all

Perfectly

Rank the following types of electron density areas by the size of the angle between them on a central atom from largest to smallest;

Bonding-pair to bonding-pair
Lone-pair to lone-pair
Lone-pair to bonding-pair

Biggest 1) Lone-pair to Lone-pair
2) Lone-pair to Bonding-pair
Smallest 3) Bonding-pair to Bondng-pair

How well did you know this?

Not at all

Perfectly

Give the name and size of the angle for a central atom with 2 areas of electron density

Linear

180°

How well did you know this?

Not at all

Perfectly

Give the name and size of the angle for a central atom with 3 areas of electron density

Trigonal Planar

120°

How well did you know this?

Not at all

Perfectly

Give the names and sizes of the angles for a central atom with;

i) 4 bonding pairs of electrons
ii) 3 bonding pairs of electrons and 1 lone pair
iii) 2 bonding pairs of electrons and 2 lone pairs

i) Tetrahedral - 109.5°
ii) Trigonal pyramid - 107°
iii) non-linear or bent - 104.5°

How well did you know this?

Not at all

Perfectly

Give the name and sizes of the angles for a central atom with 5 areas of electron density

Trigonal Bipyramid
Trigonal - 120°
Pyramid - 90°

How well did you know this?

Not at all

Perfectly

Give the name and size of the angle for a central atom with 6 areas of electron density

Octahedral

90°

How well did you know this?

Not at all

Perfectly

The molecule ICl contains a covalent bond

a) Showing the outer-shell electrons only, draw a dot-and-cross diagram to show the bonding in ICl
b) State what a covalent bond is and why forming them makes atoms more stable
c) In terms of attractive forces, explain how a covalent bond holds the atoms in molecules such as F₂ and O₂ together

a) [see card 1]
b) A covalent bond is a pair of electrons that is shared between two atoms. The atoms become more stable by sharing electrons because they achieve full outer shells of electrons
c) There is a force of electrostatic attraction between the positive nuclei of the atoms and the negative electrons between them

How well did you know this?

Not at all

Perfectly

The molecules BH₃ and NH₃ both consist of a central atoom surrounded by three Cl atoms - but they are not the same shape.
Predict the shapes of the two molecules and explain why they are different

BH₃ is trigonal planar
NH₃ is trigonal pyramid
They are different shapes because in NH₃ there is a lone pair on the central atom, but not in BH₃.

How well did you know this?

Not at all

Perfectly

Sodium Choride and Silicon Dioxide consist of different types of giant lattice structure.
Name the structures and describe a test that you could do to tel l them apart

Sodium Chloride is ioonic
Silcion Dioxide is giant covalent
They could be distinguished from one another by trying to dissolve them in water since Sodium Choride would dissolve but Silicon Dioxide wouldn’t

How well did you know this?

Not at all

Perfectly

Define an acid using the Bronsted-Lowry theory

A proton donor

What's the functional group in an alkene?

C=C

Name 2 homologous series whose functional groups contain C-O bonds?

Alcohols (-OH) Ethers Ester Carboxylic Acid (-OH)

Name the product and the type of reaction when a halogenoalkane reacts with an aqueous solution of sodium hydroxide

Alcohol | Nucleophilic Substitution

Name the organic product in the reaction of ethene with bromine

Dibromoethane

An organic compound has the molecular formula C₃H₆O. The structral formula is thought to either be A or B below: A: CH₂=CHCH₂OH B: CH₃CH₂CHO i) Name all of the functional groups in molecule A ii) Describe a test that would give a positive result with compound A but not with compound B. State the reagents you'd use and the results of the test with compound A

i) Alkene and alcohol | ii) Shake the compound with Bromine water. A would cause the colour of solution to change to clear colourless

1,2-dibromoethane can be made from ethanol by the following series of reactions: Ethanol → X → 1,2-dibromoethane i) X is produced by dehydration of ethanol. Name X and state the reagents and condiions required to produce it from ethanol ii) What reagents and conitions are required to convert X into 1,2-dibromoehtane

i) Ethene Either pass ethanol vapour over Al₂O₃ heated to 400°C OR Reflux ethanol with conc. H₂SO₄ ii) Br₂ at 20°C (room temp.)

Give the reagents and products for the Oxidation of the following alcohols i) distilled 1° ii) 1° under reflux iii) 2° under reflux iv) 3°

i) Acidified K₂Cr₂O₇ to produce Aldehydes ii) Acidified K₂Cr₂O₇ to produce Carboxylic Acids iii) Acidified K₂Cr₂O₇ to produce Ketones iv) do not oxidise

What is the name of the -COOH functional group?

Carboxylic Acid

How could you use sodium carbonate as a test for carboxylic acids?

Carboxylic acids react with Carbonates to form salts, carbon dioxide and water. If a carboxylic acids group is present in a compound, carbon dioxide will fizz out of the solution as sodium carbonate is added

Which two functional groups can be reacted together to form an ester?

Alcohols and Carboxylic acids

To what homologous series does ethyl butanoate (CH₃CH₂CH₂COOCH₂CH₃) belong to?

Esters

Ethyl butanoate (CH₃CH₂CH₂COOCH₂CH₃) can be formed by reacting an alcohol with a carboxylic acid. i) Name the alcohol ii) Draw the displayed formula of the carboxylic acid and name it iii) When the alcohol reacts with the carboxylic acid, two products are formed - ethyl butanoate and one other. What is the other product?

i) Ethanol ii) Butanoic Acid (see card 2) iii) water

The Plastic PET (aka Terylene) is made by heating together benzene-1,,4-dicarboxylic acid and molecule A (see Card 3) i) name molecue A ii) Benzene-1,4-dicarboxylic acid reacts with excess sodium hydroide to form a salt and water. Write an equation for this reaction.

i) Ethane-1,2-diol | ii) see card 4

How can you test a compound to see if it is a phenol?

Add iron (III) Chloride solution and the solution will turn purple if there is phenol present

Are phenols acidic, alkaline or neutral? Explain your answer

Phenols are weakly acidic because phenol dissociates in water to form a phenoxide ion and an H⁺

Why are phenols reacted with acyl chlorides instead of carboxylic acids to make esters?

Phenols react very slowly with carboxylic acids, so it's faster to use acyl chlorides

Name the compounds on card 5

Answers from left to right: i) Phenol ii) 2-methylphenol iii) 4-chlorophenol iv) 4-nitrophenol

Salicylic acid is a precursor of aspirin (shown on card 6) Aspirin is produced when the phenol group of salicylic acid reacts with ethanoyl chloride. This is an esterification reaction. i) Draw the structure of asprin ii) What other product is formed in this reaction?

i) see card 7 | ii) Hydrogen Chloride gas - HCl (g)

Carboxylic acids and phenols both have pH values below 7, and both react with strong bases such as sodium hydroxide. Describe two tests that you could use to tell a phenol and a carboxylic acid apart [6 Marks]

TEST 1: Add sodium carbonate (or other suitable carbonate). The carboxylic acid will fizz (CO₂ produced) but the phenol will not react. TEST 2: Add iron (III) chloride. The carboxylic aid will not react but the phenol will produce a purple coloured solution.

A food chemist wishes to make the ester phenyl ethanoate (CH₃COOC₆H₅) to test as an artificial flavouring. The chemist first tries to make tthe ester using a carboxylic acid. Name the carboxylic acid that would be used, and a compound that he should try to react with to make phenyl ethanoate.

Ethanoic Acid and Phenol

A food chemist wishes to make the ester phenyl ethanoate (CH₃COOC₆H₅) to test as an artificial flavouring. The reaction involving the carboxylic acid is very slow, so the chemist tries to find a more reactive compound that will produce the same ester i) Give the structural formula and name of a suitable compound ii) In this reaction, what else would be produced apart from the ester?

i) Ethanoyl Chloride (see card 8 for structural formula) | ii) HCl

What is the differenc between an aldehyde and a ketone?

Aldehydes have their carbonyl group at the end of their carbon chain Ketnes have their carbonyl group in the middle of their carbon chain

Name each moleule on card 9

i) Propanal ii) Pentan-2-one iii) Methanal iv) Propanone

Describe the setup required for a reflux reaction

A round bottomed flask containing the substance and some anti-bumping granules, above a heat source whilst connected to an open top, vertical Liebig condenser

Name the mechanism by which a CN⁻ ion reacts with an aldehyde or ketone

Nucleophilic Addition

Ethanol is heated with acidified potassium dichromate. As soon as the product forms it is removed from the reaction mixture by distilation. a) Name the type of reaction that is occuring b) Name the product and the functional group that it contains c) i) Explain why it i imprortant that the product is not left in the reaction mixture when it forms ii) Why is this not a problem when the same reaction is performed with propan-2-ol in place of ethanol

a) Oxidation b) Ethanal (Functional group is carbonyl C=O) c) i) If ethanal is left in the reaction mixture it may oxidise further to form ethanoic acid ii) Propan-2-ol oxidises to a ketone, which cannot be oxidised further

An alcohol, X, is refluxed with an oxidising agent to fornm compound Y, which when reacted with HCN forms 2-hydroxy-2-methylbutanenitrile (shown on card 10). Draw the displayed formulae and give the names of X and Y

X is butan-2-ol (see card 11) | Y is butanone (see card 11)

Look at the structural formulaee of the carbonyl compounds, A, B and C below. A: CH₃CHO B: CH₃COCH₃ C: (CH₃)₂CHCHO For each one state: i) The name of the compound ii) The name of the alcohol that is oxidised to produce the compound

``` A i) Ethanal ii) Ethanol B i) Propanone ii) Propan-2-ol C i) 2-methylpropanal ii) 2-methylpropan-1-ol ```

Name and describe 5 types of organic reaction

- Rearrangement - the atoms change the way in which they're ordered - Addition - molecules add together - Substitution - One functional group is "swapped" for another - Elimination - Atoms are removed from a molecule - Condensation - This is addition followed by elimination

Give the equation used to calculate atom economy

atom economy = (Mr of desired product / ∑Mr of all products) X 100

What is atom economy a measure of?

It is a measure of the proportion of reactant atoms that become part of a desired product in the balanced equation

Why do addition reactions have high atom economies?

Because all reactants end as the desired product

Chlorine can be reacted with ethane or ethene to make a chloroalkane: Ethane: C₂H₆ + Cl₂ → C₂H₅Cl + HCl Ethene : C₂H₄ + Cl₂ → C₂H₄Cl₂ i) classify each reaction above as rearrangement, addition substitution or elimination ii) Calculate the atom economy of both reactions iii) Explain why one reaction has a lower atom economy than the other

i) Ethane: Substitution Ethene: Addition ii) Ethane Atom Economy 100[(2x12)+(5x1)+35.5]÷[(2x12)+(6x1)+(35.5x2)] = 63.9% Ethene Atom Economy 100[(2x12)+(4x1)+(35.5x2)]÷[(2x12)+(4x1)+(35.5x2)] = 100% iii)The ethene reaction has a higher atom economy since there is only 1 product

Maleic anhydride, C₄H₂O₃, is a very veratile chemical used to make oil additives, artificial sweeteners and many other things. It can be prepared industrially by oxidising benzene or but-2-ene. There are very few commercial chemical companies that use the oxidation of benzene anymore. Using the equations below, calculate the atom economy for each process and use your answer to suggest why butene oxidation might be prefered Benzene oxidation: C₆H₆ + 4.5O₂ → C₄H₂O₃ + 2CO₂ + 2H₂O Butene oxidation: C₄H₈ + 3O₂ → C₄H₂O₃ + 3H₂O

``` Mr of C₄H₂O₃ = 98 Mr of CO₂ = 44 Mr of H₂O = 18 Benzene oxidation atom economy = 44.1% Butene oxidation atom economy = 64.4% The atom economies show that butene oxidation is less wasteful, and thus a more efficient use of resources ```

Why might it be necessary to change the molecular structure of a drug even if it works well?

The current structure might have some bad side effects or might not be as effective or potent as needed

Why do pharmaceutical companies often make large numbers of very similar molecules when they are developing new drugs?

Because a small change in structure may have a big difference in properties

What is the technique of making a large number of very similar molecules at once called?

Combinatorial Chemistry

List 3 reasons why a drug may fail during clinical trials

- It is found to be toxic or have damaging side effects - It doesn't have the medicinal effects that the trials are looking for - It isn't better or benificial in different areas of treatment to anything currently available

The diagram on card 12 shows 3 molecules that were tested as candidates for a drug to relieve high blood pressure and how active (effective at lowering blood pressure) they were. i) Write the formulae of any functional groups that you think must be present for the drug to work well ii) For each of the functional groups that you identified in part i), explain how you can tell that it has to be present for the drug to work

i) Hs and COOH ii) The only difference between Molecule 1 and Molecule 2 is that the HS group isn't present in Molecule 2 (which has a comparatively low activity). In Molecule 3, although the HS group is the, the COOH group is missing and this drug also has very low activity.

Combinatorial chemistry is used by pharmaceutical companies. i) Explain what the term "combinatorial chemistry" means ii) How does combinatorial chemistry help chemists when they are looking for new drugs?

i) Combinatorial chemistry is a process of synthesising a large number of structurally similar molecules at the same time ii) Because small differences in the structure of molecules can have large effects on their properties as a drug, it is important to test many similar molecules to find the best combination of properties (or to find an effective drug with minimal side effects)

What's in Medicine Flashcards

(65 cards)