Question

Benzoic acid, C6H5COOH, melts at 122°C. The density in the liquid state at 130°C is 1.08g/cm3. The density of solid benzoic acid at 15°C is 1.266g/cm3. In which of these two states is the average distance between molecules greater? If you converted a cubic centimeter of liquid benzoic acid into a solid, would the solid take up more, or less, volume than the original cubic centimeter of liquid?

Answer 1

Answer:

The correct answer is: Liquid state;  Less volume

Explanation:

Density (ρ) is the physical property of a substance. It is equal to the mass per unit volume of a given substance. The SI unit of density is kg/m³.

Density (ρ) = mass (m) ÷ volume (V)

Given: density of liquid benzoic acid = 1.08 g/cm³ and density of solid benzoic acid = 1.266 g/cm³

As 1.08 g of benzoic acid occupies 1 cm³ volume in the liquid state and 1.266 g of benzoic acid occupies 1 cm³ volume in the solid state.

Thus the molecules of benzoic acid are more densely packed in the solid state as compared to the liquid state.

Therefore, the average distance between the molecules of benzoic acid is greater in the liquid state as compared to the solid state.

Also, as the benzoic acid in the solid state is more densely packed than benzoic acid in the liquid state.

So, if 1 cm³ of liquid benzoic acid is solidified, then the volume occupied by solid benzoic acid having the same mass, occupies less space or volume as compared to the liquid benzoic acid.