163k views
0 votes
When 1 mole of hydrogen gas (H2) reacts with excess oxygen to form water at a constant pressure, 241.8 KJ of energy is released as heat. Calculate ΔH for a process in which 21.9 g sample of hydrogen gas (H2) reacts with excess oxygen at constant pressure.

User Bitfox
by
7.4k points

1 Answer

6 votes

Answer:

The value of ΔH when 21.9 grams of hydrogen gas reacts with an excess of oxygen gas is 2,647.71 kilo Joules.

Step-by-step explanation:


H_2+(1)/(2)O_2\rightarrow H_2O,\Delta H=-241.8 kJ

Mass of hydrogen gas = 21.9 g

Moles of hydrogen gas =
(21.9 g)/(2 g/mol)=10.95 mol

When 1 mole of hydrogen gas reacts with an excess oxygen gas it gives 241.8 kJ of heat.

Then 10.95 moles hydrogen gas will give :


241.8 kJ* 10.95 =2,647.71 kJ

The value of ΔH when 21.9 grams of hydrogen gas reacts with an excess of oxygen gas is 2,647.71 kilo Joules.

User Gene Vayngrib
by
8.3k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.