A sample of Ar gas at 35°C occupies a volume of 1.50 L at a pressure of 3.2 atm. How many moles of the gas are present in the sample?

The moles of the gas that are present in the sample is 0.1898 moles

calculation

Use the Ideal gas equation

that is PV = nRT

where p (pressure) = 3.2 atm

V (volume) = 1.50 L

n (number of moles) = ?

R (gas constant) = 0.0821 atm. L/mol. K

T (temperature) = 35 + 273 = =308 k

make n the subject of the formula by diving both side by RT

n = Pv/RT

n is therefore = [3.2 atm x 1.50 L) / (0.0821 atm. L/mol. K x 308 K) = 0.1898 moles