I) The compound is CH3-CH(CH3)-CH3.

7. a)

i) The compound is $\text{CH}_3-\text{CH}(\text{CH}_3)-\text{CH}_3$.
Name: 2-methylpropane

ii) The compound is $\text{CH}_3-\text{CH}_2-\text{C}\equiv\text{C}-\text{CH}_3$.
Name: Pent-2-yne

b) To distinguish between 2-methylpropane (an alkane) and pent-2-yne (an alkyne):
Add bromine water (reddish-brown).

• Pent-2-yne (alkyne) will decolorize the bromine water because it is unsaturated and undergoes an addition reaction.
• 2-methylpropane (alkane) will not decolorize the bromine water because it is saturated and does not readily undergo addition reactions.

8. a) Gay-Lussac's Law of combining volumes states that when gases react, they do so in volumes that bear a simple whole-number ratio to one another and to the volumes of the gaseous products, provided that all volumes are measured at the same temperature and pressure.

b) Step 1: Write the balanced chemical equation for the combustion of carbon (II) oxide.

$$\text{2CO}(g) + \text{O}_2(g) \rightarrow \text{2CO}_2(g)$$