Question

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

Answer 1

6.67moles

Explanations:

Given the balanced chemical reaction between hydrogen and oxygen expressed as:

`2H_2+O_2\rightarrow2H_2O`

First, you need to calculate the moles of water produced.

`\begin{gathered} \text{Moles}=\frac{Mass}{\text{Molar mass}} \\ \text{Moles of water=}(120)/(2(1)+16) \\ \text{Moles of water}=(120)/(18) \\ \text{Moles of water}=6.67\text{moles} \end{gathered}`

Based on stochiometry, 2 moles of hydrogen produces 2 moles of water, hence the moles of hydrogen that will be needed to produce 120g of water is 6.67moles