Question

Part A Hydrogen gas reacts with oxygen to form water. AH = -483.5 kJ 2 H20(g) 2 H2(g) +O2(g) Determine the minimum mass of hydrogen gas required to produce 177 kJ of heat. 0.732 g O 11.0 g O 0.738 g O 1.48 g Request Answer Submit Provide Feedback

Answer 1

when -483.5 KJ of heat is involved, 2 mol of H2 is reacting

So,

for -1.77*10^2 KJ, mol of H2 = -1.77*10^2*2/-483.5 KJ

= 0.7322 mol

Molar mass of H2 = 2.016 g/mol

use:

mass of H2,

m = number of mol * molar mass

= 0.7322 mol * 2.016 g/mol

= 1.48 g

Answer: 1.48 g