chemistry- word problem

Question

The reaction of calcium hydride and water produces calcium hydroxide and hydrogen as products.

How many moles of H2(g) will be formed in the reaction between 0.70 mol CaH2(s) and 1.98 mol H2O(l)

Answer 1

by inspection, the balanced equation is CaH₂ + 2 H₂O -->Ca(OH)₂ + 2 H₂ .

 

 0.70 moles of calcium hydride requires twice that, or 1.40 mole water to complete, meaning 0.70 moles calcium hydride is the limiting reactant.  

 

the equation shows a 2 to 1 ratio between calcium hydride and hydrogen, so 1.40 moles H₂ is produced