Question

The density of air at room temperature is about 1.2 g/L. This is the same as

A) 12 g/m3.
B) 120 g/m3.
C) 1200 g/m3.

Answer 1

The correct answer is
C) 1200 g/m3.

Let's see why. The relationship between liters and cube decimeters is

`1 L = 1 dm^3`
Therefore,

`1 g/L= 1 g/dm^3`
However, we also know that

`1 dm^3 = 10^(-3) m^3`
Therefore,

`1 L = 10^(-3) m^3`
and

`1 (g)/(L)= 1 (g)/(10^(-3) m^3) =1 \cdot 10^3 (g)/(m^3) =1000 (g)/(m^3)`

Therefore, the density of the problem
`1.2 g/L` becomes

`d=1.2 g/L=1200 g/m^3`