Question 1.23 - Chemistry: Molecular Nature Of Matter And Change

Question

For each of the following cases, state whether the density of the object increases, decreases, or remains the same:

(a) A sample of chlorine gas is compressed.

(b) A lead weight is carried up a high mountain.

(c) A sample of water is frozen.

(d) An iron bar is cooled.

(e) A diamond is submerged in water.

Step-by-Step Solution

Answer

Answer

 

(a) The density of a chlorine gas sample increases when it is compressed.

(b) The density of a lead weight remains the same when it is carried up a high mountain.

(c) When a sample of water is frozen, the density is decreased.

(d) The density of an iron bar is increased when it is cooled.

(e) When a diamond is submerged in water, the density remains the same.

Density:

The density of an object is an intensive property. But it is interrelated with the mass and volume of the object. It is directly proportional to mass and inversely proportional to volume.

Density in change (a)

In this process, the volume of the chlorine gas is increased, but the mass of the gas remains the same. Hence, the density of a sample of chlorine gas is increased.

Density in change (b)

A lead weight does not change its mass and volume when carried up a high mountain. Hence, its density remains the same.

Density in change (c)

One of the few compounds that expands when frozen is water. The mass remains constant while the volume expands. Therefore, the density is decreased.

Density in change (d)

 

Iron is a metal that shrinks when it is cooled. In this process, the volume decreases, but the mass remains constant. Therefore, the density of an iron bar is increased.

Density in change (e)

The mass and volume of the diamond are unaffected by water. Hence, the density of a submerged diamond remains the same.