Organic Chemistry

Question 1

Homologous series?

Answer 1

• a family of organic compounds with the same functional group but each successive member differing by CH2

Question 2

General formula?

Answer 2

• algerbraic formula that can describe any member of a family of compounds

Question 3

Empirical formula?

Answer 3

• simplest ratio of atoms of each element in a compound

Question 4

Molecular formula?

Answer 4

• the actual number of atoms of each element in a molecule with any functional indicated

Question 5

What are the general formulas for an alkane, alkene, alcohol and Cycloalkanes?

Answer 5

• Alkane : CnH2n+2
• alkene : CnH2n
• alcohol : CnH2n+2Oj
• Cycloalkanes : CnH2n

Question 6

Which functional groups are automatically carbon 1?

Answer 6

• carboxylic acids

* aldehyde

Question 7

When do you use dashes and comas?

Answer 7

• use dashes between numbers and letters

* use commas between numbers

Question 8

Structural isomer?

Answer 8

• have the same molecular formula but different structural formula

Question 9

For alcohols?

Answer 9

• if it has an another functional group aswell, you add the prefix hydroxy
• if it has more than one OH attatched you use di, tri etc with the e added to the stem e.g ethane 1,2-diol

Question 10

For ketones?

Answer 10

• When ketones have 5C’s or more in a chain then it needs a number to show the position of the double bond. E.g. pentan-2-one
• If two ketone groups then
  di is put before –one and
  an an e is added to the H stem

Question 11

Stereoisomerism?

Answer 11

• have the same structural formula but the atoms are arranged differently in space

Question 12

How do E/Z isomerism occur?

Answer 12

• it occurs in some alkenes due to the restricted rotation of the carbon to carbon double bond
• there are two different groups/atoms attatched to both ends of the double bond

Question 13

When you get two different groups attactched to each carbon the the double bond you get what?

Answer 13

• E isomer

* Z isomer

Question 14

What is E/Z isomerism sometimes called?

Answer 14

• cis-trans isomerism

–> where cis is Z and trans is E

Question 15

What needs to happen for a reaction to start?

Answer 15

• bonds need to be broken

* new bonds need to be made

Question 16

Homolytic fission?

Answer 16

• where the covalent bond breaks equally so each product recieved one of the shared pair of electrons to form radicals

Question 17

What is a radical?

Answer 17

• a species with an unpaired electron

–> they are highly reactive

Question 18

Hetrolytic fission?

Answer 18

• where the covalent bond splits unequally so one product gets both the electrons from the shared pair and the other gets nothing producing ions
• its forms a cation and an anion

Question 19

What does a curly arrow show?

Answer 19

• the movement of a pair of electrons

–> either showing breaking or formation of a covalent bond

Question 20

What is a nucleophile?

Answer 20

• an electron pair donor

Question 21

What is a electrophile?

Answer 21

• electron pair acceptor

Question 22

Atom economy?

Answer 22

Total mass of reactants. x100

• atom economy is a measure of the efficiency of a reaction

Question 23

Define functional group?

Answer 23

• a group of atoms responsible for the characteristic reactions of a compound

Question 24

How to remember to work out percentage yield?

Answer 24

• e.g CH3OH + [O] –> CH3CHO + H2O

      1. 3                         2.5  1. You find the moles of the ethanol  2. Then find moles of ethanal (1:1) 3. Find mass of the ethanal ( this is the TY) 4. Calculate % yield