Organic compounds

Question 1

Functional group

Answer 1

Atom/ group of atoms that give compound its characteristic properties

Question 2

Homologous series

Answer 2

A series of compounds with the same functional group

Question 3

Hydrocarbon

Answer 3

Compound of carbon and hydrogen only

Question 4

Saturated compound

Answer 4

One in which all the C to C bonds are single bonds
Eg. Alkanes

Question 5

Unsaturated compound

Answer 5

Contains C two C multiple ones
Eg. Alkenes

Question 6

Molecular formula

Answer 6

Shows the atom and how many of each type there are in a molecule of a compound

Question 7

Displayed formula

Answer 7

Shows ALL bonds and atoms in a molecule

Question 8

Shortened formula

Answer 8

Shows the group in sufficient detail that this structure is unambiguous

Question 9

Skeletal formula

Answer 9

Shows the carbon and hydrogen backbone of a molecule as a series of bonds with any functional groups attached

Question 10

Empirical formula

Answer 10

Formula of a compound with the atoms of the elements to the simplest integer ratio

Question 11

Structural isomers

Answer 11

Compounds with the same molecular formula but different structural formulae

Question 12

Van der waals forces

Answer 12

Dipole - dipole or temporary dipole - temporary dipole interaction between atoms and molecules

Question 13

Naming organic compounds

Answer 13

Alkanes- A saturated hydrocarbons with single c-c bonds

Alkenes - unsaturated hydrocarbons with C- C double bond

Halogenoalkanes- Hydrogen swapped for a halogen

Alcohols- Compounds containing OH

Carboxylic acids- Contain COOH

Question 14

prefixes

Answer 14

Meth- 1 number of C
Eth- 2
Prop-3
But-4
Pent- 5
Hex- 6
Hept- 7
Oct- 8
Non- 9
Dec-10

Question 15

general formula of alkanes

Answer 15

CnH2n+2

Question 16

general formula of alkenes

Answer 16

CnH2n

Question 17

how to work out empirical formula from molecular

Answer 17

find simplest ratio
eg. Mr of ethane= C2H6
ratio- 2:6
1:3
Empirical- CH3

Question 18

The effect of chain length on melting and boiling temperatures

Answer 18

Energy is needed to overcome forces when a substance melts or boils
Hydrocarbons are nonpolar- Electronegativities of carbon hydrogen are similar
Means temporary dipole - temporary dipole van der Waals forces are present between the molecules (Weak intermolecular forces)
The more surface there is in contact, the stronger the forces meaning more energy is needed to overcome the forces and melting- boiling temperatures are higher

Question 19

The effects of branching on boiling temperatures

Answer 19

more branches- more spherical
Spherical shape means less surface area available for contact
Compared to straight chains where more surface area is available
More branches, lower boiling temp
Less surface contacts between molecules
Means weaker van der Waals forces between molecules and so less energies needed to separate them

Question 20

The effects of functional groups on boiling temperatures

Answer 20

Molecules that form hydrogen bonds will have a higher boiling temperature than those of a similar size that cannot hydrogen bond
bc hdrogen bonds are he srongest bond

Question 21

solubility
of compounds

Answer 21

Hydrocarbons cannot dissolve in water because they only form WDW interactions between molecules and are not able to form attractions with polar water molecules

Alcohol and carboxylic acids- Have - 0H groups that can form hydrogen bonds with water. Therefore soluble in water
Solubility decreases as chain length increases Size of the hydrocarbon part of molecule increases and exerts such a large hydrophobic effect that compound is no longer soluble