# How to find the mass of air

Air is the natural mix of gases consisting, mostly, of nitrogen and oxygen. The mass of air in unit of volume can change if proportions of the components making it change and also at temperature change. The mass of air can be found, knowing the volume which it occupies, or amount of substance (quantity of particles).

## It is required to you

• the air density, molar mass of air, amount of air, the volume occupied by air

## Instruction

1. Let the volume of V which occupies air be known to us. Then on the known formula m = p*V where - p - density air, we can find the mass of air in this volume.

2. Density of air depends on its temperature. Density of dry air is calculated through Klapeyron's equation for ideal gas on a formula: p = P/(R*T), where P is absolute pressure, T is absolute temperature in Kelvins, and R is a specific gas constant for dry air (R = 287.058 J / (kg*k)). At sea level at a temperature of 0 wasps density of air is equal to 1.2920 kg / (м^3).

3. If the amount of air is known, then its weight can be found on a formula: m = M*V, where V - amount of substance in moths, and M - the molar mass of air. The average relative molar mass of air is equal to 28.98 g/mol. Thus, having substituted it in this formula, you receive the mass of air in grams.

Author: «MirrorInfo» Dream Team