Respuesta :
Answer: The mass of the excess reactant (oxygen gas) is 3.136 grams
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] .....(1)
- For HCl:
Given mass of HCl = 53.2 g
Molar mass of HCl = 36.5 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of HCl}=\frac{53.2g}{36.5g/mol}=1.46mol[/tex]
- For oxygen gas:
Given mass of oxygen gas = 26.5 g
Molar mass of oxygen gas = 32 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of oxygen gas}=\frac{26.5g}{32g/mol}=0.828mol[/tex]
The chemical equation for the reaction of HCl and oxygen gas follows:
[tex]2HCl+O_2\rightarrow H_2O+Cl_2[/tex]
By Stoichiometry of the reaction:
2 moles of HCl reacts with 1 mole of oxygen gas
So, 1.46 moles of HCl will react with = [tex]\frac{1}{2}\times 1.46=0.73mol[/tex] of oxygen gas
As, given amount of oxygen gas is more than the required amount. So, it is considered as an excess reagent.
Thus, HCl is considered as a limiting reagent because it limits the formation of product.
Excess moles of oxygen gas = (0.828 - 0.73) = 0.098 moles
Now, calculating the mass of oxygen gas from equation 1, we get:
Molar mass of oxygen gas = 32 g/mol
Excess moles of oxygen gas = 0.098 moles
Putting values in equation 1, we get:
[tex]0.098mol=\frac{\text{Mass of oxygen gas}}{32g/mol}\\\\\text{Mass of oxygen gas}=(0.098mol\times 32g/mol)=3.136g[/tex]
Hence, the mass of the excess reactant (oxygen gas) is 3.136 grams
