Isomerism

Question 1

two compounds can have the same molecular formula but different……, making them………..

Answer 1

structural formulae, making them structural isomers

Question 2

the two types of structural isomerism are

Answer 2

chain isomerism and position isomerism

Question 3

chain isomerism refers to molecules with

Answer 3

different carbon chains

Question 4

butane and methylpropane are examples of what kind of isomerism

Answer 4

chain isomerism

Question 5

butane and methylpropane are chain isomers because

Answer 5

their carbon chains are different

Question 6

position isomerism refers to molecules with

Answer 6

the same functional group attached in different positions on the same carbon chain

Question 7

propan-1-ol and propan-2-ol are examples of what kind of isomerism

Answer 7

position isomerism

Question 8

true or false: two molecules can be both chain and position isomers?

Answer 8

true

Question 9

in organic chemistry, we use ‘stereo’ to mean

Answer 9

the different ways to arrange atoms or groups of atoms

Question 10

stereoisomers have the same….. and same……. but different……..

Answer 10

molecular formula and structural formula, but different arrangements

Question 11

when showing stereoisomers, we have to (specific way of drawing bonds)

Answer 11

draw the bonds at 120 degree angles around the carbon atoms in question, having two groups of atoms or atoms bonded on each carbon of the double C=C

Question 12

by drawing the bonds at 120 degree angles in stereoisomers, we can see……and…….notation

Answer 12

trans- (opposite) and cis- (same side)

Question 13

trans means

Answer 13

the same groups of atoms or single atoms are on opposite sides of the C=C bond and opposite sides of the molecule

Question 14

cis means

Answer 14

the same groups of atoms or single atoms are still on opposite side of the C=C bond, but on the same side of the molecule

Question 15

compounds which require cis- and trans- to name them are called

Answer 15

geometric isomers

Question 16

geometric isomerism is a kind of

Answer 16

stereoisomerism

Question 17

geometric isomerism exists in…..but not……

Answer 17

alkenes but not alkanes

Question 18

geometric isomerism cannot occur in alkanes as

Answer 18

there is no double bond which stops groups attached to the double C=C bond from rotating

Question 19

what causes geometric isomerism?

Answer 19

the double C=C bond in alkenes prevent groups attached to the carbons in the double C=C from rotating, so restricted rotation is created

Question 20

the three steps for E-Z notation are

Answer 20

1) Use the part of the name that can be used for both isomers using normal nomenclature
2) Use priority rules to decide which of the two atoms or groups of atoms on each side will be used to compare with the other side. Use the atomic number of the atoms to decide, the highest atomic number is used
3) Now decide whether the highest priority atoms are on the same side (Z) or opposite (E) sides of the molecule