Answer:
89.6 L of H₂ will be produced at STP from 2 moles of CaH₂ and excess water if the reaction goes to 100% completion.
Step-by-step explanation:
The balanced chemical equation of the reaction between calcium hydride, CaH₂ and excess water to produce calcium hydroxide and hydrogen gas is given below:
CaH₂ (s) + 2H₂O (l) ----> Ca(OH)₂ (aq) + 2H₂ (g)
From the equation of the chemical reaction above, 1 mole of calcium hydride reacts with 2 moles of water to produce 2 moles of hydrogen gas.
Then, 2 moles calcium hydride will react with excess water to produce 2 × 2 -moles of hydrogen gas = 4 moles of hydrogen gas.
One mas a gas at STP has a volume of 22.4 L
4 moles of hydrogen gas will have a volume of 4 × 22.4 L = 89.6 L
Therefore, 89.6 L of H₂ will be produced at STP from 2 moles of CaH₂ and excess water if the reaction goes to 100% completion.