Question

Calculate the number of moles of hydrogen gas present in a 0.5 dm³ sample of hydrogen gas at a pressure of 101.325 kPa at 27 °C.

Answer 1

Given: V = 0.5 dm³ = 0.5 × 10^-3 m³ , P = 101.325 kPa = 101.325 × 10³ Pa = 101.325 × 10³ Nm^-2

T = 27 °C = 27 + 273.15 K = 300.15 K, R = 8.314 J K^-1 mol^-1

To find: n = number of moles of gas 

Formula: PV = nRT 

Calculation: According to ideal gas equation,

The number of moles of hydrogen gas present in the given volume is 0.020 moles.