# Calcium hydride reacts with water to form calcium hydroxide and hydrogen gas. How many grams of calcium hydride are needed to form 8.5 grams of hydrogen?

##### 1 Answer

Mar 20, 2016

#### Answer:

Approx.

#### Explanation:

The balanced equation gives a 1:1 stoichimetry between calcium hydride and dihydrogen gas, We need to (i) work out the molar quantity of dihydrogen, and (ii) convert this into an equivalent mas of

So, if 4 mol of calcium hydride are required. This gives a mass of