Answer:
[tex]6.67\text{ moles}[/tex]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:
[tex]\begin{gathered} x\times18\text{ = 120}\times1 \\ x\text{ = }\frac{120}{18} \\ x\text{ = 6.67 moles} \end{gathered}[/tex]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
