Question

2H2 + O2 --> 2H2OHow many moles of hydrogen gas are needed to produce 120. g of water?

Answer 1

`6.67\text{ moles}`

Step-by-step explanation:

Here, we want to get the number of moles of hydrogen needed to produce 120 g of water

1 mole of water has a weight of 18g

x moles of water will have a weight of 120g

Mathematically:

`\begin{gathered} x*18\text{ = 120}*1 \\ x\text{ = }(120)/(18) \\ x\text{ = 6.67 moles} \end{gathered}`

From the equation of the reaction, 2 moles of hydrogen gas produced 2 moles of water.

This means that their mole ratios are equal

Hence, 6.67 moles of hydrogen will produce 6.67 moles of water