# If we start with 9.0 grams of H2O, how many moles of H2 will be produced?Answer the question using the balanced equation below: 2 K + 2 H2O → 2 KOH + H2 If we start with 9.0 grams of H2O, how...

If we start with 9.0 grams of H2O, how many moles of H2 will be produced?

Answer the question using the balanced equation below: 2 K + 2 H2O → 2 KOH + H2 If we start with 9.0 grams of H2O, how many moles of H2 will be produced? Show your work, including all conversion factors and all units.

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### 2 Answers

Weight of H2O = 9 g

The number of mols of H2O = 9 g/ 18 g per mol

= 0.5 mol

According to stoichiometry of the given equation, 2 mols of H2O will give 1 mol of H2.

Therefore H2 produced by 0.5 mol of H2O is,

= 1/2 x 0.5 mol = 0.25 mol

**Therefore 0.25 mol of H2 is produced.**

### User Comments

the balanced reaction is

2 K + 2 H2O → 2 KOH + H2

now we have 9 g of water and the molar mass of water is 18g/mol

moles = mass/molar mass

moles of water = 9g/18(g/mol) =0.5 mol H2O

if we look ta the reaction the molar ratio is 2 H2O : 1 H2

that is 2 mol of water will produce 1 mol of H2

0.5 mol H2O*(1 mol H2/ 2 mol H2O)

0.25 mol H2