2.9 Density of Liquids and Gases

Question 1

What equation is the density of a material defined by?

Answer 1

Density (kg/m3) = mass (kg) / volume (m3)

Question 2

To measure density, what do you need?

Answer 2

Mass and Volume

Question 3

Calculate the density of iron, given a block of iron with a mass of 395kg and a volume of 0.05m2.

Answer 3

Density of iron = 395 kg/0.05m2 = 7900kg/m2

Question 4

What can mass be measured with?

Answer 4

A Balance

Question 5

What do you need to measure the density of a gas?

Answer 5

Mass and Volume

Question 6

A metal container of volume 1.5m3 has a mass of 20.0kg when full of methane gas. The container has a mass of 19.7kg when it is empty. What was the density of a gas when it was inside the container?

Answer 6

The mass of gas was 0.3kg (20kg - 19.7kg)
Density = mass/volume
= 0.3kg/1.5m3
= 0.2kg/m3

Question 7

When is a density of a fluid increased?

Answer 7

If there are forces that compress the fluid the density of a fluid increases. Because the particles in the fluid are forced closer together and so there are more particles in the same volume.