Chapter 4: 4.2 Constitutional Isomers

Question 1

Define:

Isomers

Answer 1

Two structures with the same molecular formula but difference in bond connectivity or 3D space occupation

Question 2

How do Constitutional Isomers differ from each other?

Answer 2

Differ in their bond connectivity

Question 3

Define:

IHD

Answer 3

Index of Hydrogen Deficiency
* A calculation to determine how many degrees of unsaturation are in a molecule

Question 4

What is the IHD sometimes also called?

Answer 4

Double Bond Equivalents (DBE)

Question 5

State:

The degree of unsaturation for:
1. A double bond
2. A triple bond
3. A ring

Answer 5

1. 1
2. 2
3. 1

Question 6

What is the general formula of a saturated alkane?

Answer 6

C (n) H (2n+2)

Question 7

State:

Formula to calculate IHD

Answer 7

IHD = [(2C + 2 + N) - H - X] / 2
* C = carbons
* N = nitrogen
* H = hydrogen
* X = halogen

Question 8

What steps do you take when drawing multiple isomers of carbon chain compounds?

Answer 8

1. Assess the IHD (determine if you need a ring or multiple bond)
2. Draw all the possible chain lengths and then look at branching sites