Question

Hydrogen produced from a hydrolysis reaction was collected over water. The data is compiled in the table. Total volume of H2(g) collected 96.96 mL Temperature 25.0°C Barometric pressure 742 mmHg Vapor pressure of water at 25.0°C 24.0 mmHg Calculate the moles of hydrogen gas produced by the reaction. moles: mol H2

Answer 1

We can use Ideal gas equation to calculate the moles of H2.

PV= nRT

P = Pressure in atm                       V= Volume in Liter

n = no of moles               R = 0.08206 L atm K-1 Mol-1

T = Temperature in Kelvin

Pressure of hydrogen = 742 - 24 = 718 mm Hg = 0.9447 atm

V = 96.96 ,ml = 0.09696 Liter

T = 298 K

n = PV /RT

n = 0.9447 atm x 0.09696 Liter / 0.08206 L atm K-1 Mol-1 x 273 K

n = 0.0040889 Moles

Hence 0.0040889 Moles of Hydrogen was produced.