A sample of gas at 25 C has a volume of 11 L and exerts a pressure of 0.868 atm. How many moles of gas are in the sample?

0.39 mol
3.9 mol
9.3 mol
87 mol

0.39 moles of gas are in the sample

Explanation:

An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:  

P*V = n*R*T

where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas.

In this case:

Replacing:

0.868 atm*11 L= n*0.082 *298 K

Solving:

n= 0.39 moles

0.39 moles of gas are in the sample