10. Organics (SL+HL)

Question 1

What is the prefix for 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12?

Answer 1

1= meth-
2=eth-
3=prop-
4=but-
5=pent-
6=hex-
7=hept-
8=oct-
9=non-
10=dec-
11=undec-
12=dodec-

Question 2

What is a hydrocarbon?

Answer 2

A hydrocarbon is a compound made of only hydrogen and carbon atoms

Question 3

What is the difference between alkene and alkane?

Answer 3

alkane= single bond, always tetrahedral (109.5°)
alkene= double bond, always trigonal planar (120°)

Question 4

What is the molecular formula, empirical formula, structural formula and display formula for ethane?

Answer 4

Molecular formula= C2H6
Empirical formula= CH3
Structural formula= CH3CH3
Displayed formula=

Question 5

What is the formula for alkane and alkene?

Answer 5

alkane= CnH(2n+2)
alkene= CnH2n

Question 6

What is a molecular formula?

Answer 6

A molecular formula shows the number of each atoms in a molecule

Question 7

What is an empirical formula?

Answer 7

An empirical formula is the simplest whole number ratio

Question 8

What is a display formula?

Answer 8

A display formula is the best formula because it is a diagram that shows all the atoms and most importantly, all of the bonds.

Question 9

What is a skeletal formula?

Answer 9

This uses lines to represent bonds. Each point represents a C atom. H atoms and bonds to H atoms are not usually shown (unless part of a functional group, e.g. alcohol, aldehyde). Other atoms (e.g. O, N, F, Cl, Br, I, S) are shown.

Question 10

What is nomenclature?

Answer 10

Naming of molecule following IUPAC (formula naming rules)

Question 11

What are the nomenclature rules?

Answer 11

Question 12

What are alkenes?( functional group, suffix, example)

Answer 12

Question 13

What are alcohols?( functional group, suffix/prefix, example)

Answer 13

Question 14

What are haloalkanes?( functional group, suffix/prefix, example)

Answer 14

Question 15

What are aldehydes?( functional group, suffix/prefix, example)

Answer 15

Question 16

What are ketones?( functional group, suffix/prefix, example)

Answer 16

Question 17

What are carboxylic acids?( functional group, suffix/prefix, example)

Answer 17

Question 18

What are nitriles?( functional group, suffix/prefix, example)

Answer 18

Question 19

What are amines?( functional group, suffix/prefix, example)

Answer 19

Question 20

What is structural isomers?

Answer 20

Structural isomers are molecules with the same molecular formula but a different structure e.g. chain isomers, position isomers, functional group isomers

Question 21

What is stereoisomers?

Answer 21

Stereoisomers are molecules with the same structural formula but a different spatial arrangement of atoms e.g. geometric isomers, optical isomers

Question 22

What is chain isomerism?

Answer 22

The carbon chain of molecules with the same molecular formulae can vary causing isomerism.

Question 23

What is a position isomerism?

Answer 23

Functional groups can be in different positions on the carbon chain resulting in isomers.

Question 23

What is a functional group isomerism?

Answer 23

Some compounds with the same molecular formula can contain different functional groups

Question 23

What are the two types of stereoisomerism?

Answer 23

• E/Z isomerism
• optical isomerism

Question 24

Why does stereoisomerism E/Z isomerism exist?(as in how they work)

Answer 24

• Would have to break the C=C double bond to rotate around it
  -If both C of the C=C have two different groups attached, the molecule has E-Z isomers.
  -E= entgegan (highest priority opposite)
  -Z=zusammen (highest priority together)

Question 25

How is the E and Z ismoers assigned?

Answer 25

Cahn-Ingold Priority (CIP) rules assigned priority of groups attached to C=C- the higher the atomic number of the group attached to the C’s, the higher the priority (if they are the same, look at the atoms attached to those atoms)

Question 26

What is optical isomerism?

Answer 26

Molecular have optical isomers if their mirror images are non-superimposable i.e. not the same.

Question 27

What is an example of optical isomerism?

Answer 27

Molecules containing a C with four different groups attached to it exhibit optical isomerism. A carbon atom that has four different groups attached is called a chiral(asymmetric) carbon atoms.

Question 28

What is an enantiomers?

Answer 28

Two compounds that are optical isomers of each other are called enantiomers.

Question 29

What is racemic mixture?

Answer 29

A mixture containing a 50/50 mixture of the two isomers(enantiomers) is described as being racemic mixture.

Question 30

What are the similarities and differences between optical isomers?

Answer 30

Optical isomers have the same chemical and physical properties as each other, except for their effect on plane polarised light(and how they react with other chiral compounds).

Question 31

How is plane-polarising light produced?

Answer 31

Light is a form of electromagnetic radiation and so consists of waves that vibrate in many directions perpendicular to the direction of travel. Some substances have the ability to remove from normal light all the light waves except those vibrating in a single plane - producing plane-polarised light.

Question 32

How can optical isomers affect the plane of polarised light?

Answer 32

Optical isomers can rotate the plane of polarised light (and so these compounds are said to optically active).

Question 33

What is the difference between the enantiomers effect on the plane of polarised light?

Answer 33

One enantiomer rotates it in one direction and the other enantiomer rotates it by the same amount in the opposite direction.

Question 34

What is the effect of a racemic mixture on the plane of polarised light?

Answer 34

A racemic mixture will have no effect on the plane of the light - it is optically inactive ( each enantiomer cancels out the effect of the other).