Answer: The theoretical yield of water is 162 grams.
Explanation:
To calculate the number of moles, we use the equation:
\(\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}\) .....(1)
Given mass of hydrogen gas = 18 g
Molar mass of hydrogen gas = 2 g/mol
Putting values in equation 1, we get:
\(\text{Moles of hydrogen gas}=\frac{18g}{2g/mol}=9mol\)
The chemical equation for the formation of water from hydrogen gas and oxygen gas follows:
\(2H_2+O_2\rightarrow 2H_2O\)
As, oxygen gas is present in excess. It is considered as an excess reagent.
So, hydrogen gas is considered as a limiting reagent because it limits the formation of product.
By Stoichiometry of the reaction:
2 moles of hydrogen gas produces 2 moles of water
So, 9 moles of hydrogen gas will produce = \(\frac{2}{2}\times 9=9mol\) of water
Now, calculating the mass of water from equation 1, we get:
Molar mass of water = 18 g/mol
Moles of water = 9 moles
Putting values in equation 1, we get:
\(9mol=\frac{\text{Mass of water}}{18g/mol}\\\\\text{Mass of water}=162g\)
Hence, the theoretical yield of water is 162 grams.
