Q. 11.19

Question

Heptane, used as a solvent for rubber cement, has a density of $0.68 g / m L$ and boils at $98^{°} C$ .

a. Draw the condensed structural and line-angle formulas for heptane.

b. Is heptane a solid, liquid, or gas at room temperature?

c. Is heptane soluble in water?

d. Will heptane float on water or sink?

e. Write the balanced chemical equation for the complete combustion of heptane.

Step-by-Step Solution

Verified

Answer

(a) The condensed structural and line-angle formulas for heptane $C H_{3} C H_{2} C H_{2} C H_{2} C H_{2} C H_{2} C H_{3}$ .

(b) At room temperature heptane is a liquid.

(d) Yes, heptane float on water.

(e) The balanced chemical equation for the complete combustion of heptane. $C_{7} H_{16} + 11 O_{2} \to 7 C O_{2} + 8 H_{2} O$

1Part(a) Step 1:Given information

We have been given,

The condensed structural and line-angle formulas for heptane.

2Part(a) Step 2: Explanation

We know that the formula of heptane is $C H_{3} C H_{2} C H_{2} C H_{2} C H_{2} C H_{2} C H_{3}$ ,

Heptane is made up of seven carbon atoms in a chain. Its structural formula in condensed form is,

3Part(b) Step 1:Given information

We have to find out that Is heptane a solid, liquid, or gas at room temperature

4Part(b) Step 2:Explanation

At $70$ degrees F, heptane is a liquid as long as the surrounding 'room pressure' is greater than $0.73$ psia. If we reduced the pressure to a lower level, heptane would turn into gas (at least in an equilibrium condition)

5Part(c) Step 1:Given information

We have to find out the Is heptane soluble in water.

6Part(c) Step :Explanation

A material must have the same polarity as water in order to dissolve in it; "like dissolves like." Because of its lengthy hydrocarbon chain, heptane is nonpolar and does not dissolve in water.

7Part(d) Step 1:Given information

We have to find out the heptane float on water or sink.

8Part(d) Step 2:Explanation

We know that,

This is primarily due to a phenomenon called as buoyancy. Everything displaces water in the same proportion as its volume. When the weight of an object is greater than the weight of the displaced water, the object floats.

Hence, Heptane floats because it is lighter than water.

9Part(e) Step 1:Given information

We have been given that the balanced chemical equation for the complete combustion of heptane.

10Part(e) Step 2: Explanation

The hydrocarbon combustion reaction is an exothermic reaction that releases heat energy.

$C_{7} H_{16} + 11 O_{2} \to 7 C O_{2} + 8 H_{2} O$