Answer: The theoretical yield of magnesium chloride is 58.6 g
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)
Given mass of magnesium hydroxide = 50.6 g
Molar mass of magnesium hydroxide = 58.32 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of magnesium hydroxide}=\frac{50.6g}{58.32g/mol}=0.87mol[/tex]
Given mass of HCl = 45.0 g
Molar mass of HCl = 36.5 g/mol
Putting values in equation 1, we get:
[tex]\text{Moles of HCl}=\frac{45.0g}{36.5g/mol}=1.23mol[/tex]
- The chemical equation for the reaction of magnesium hydroxide and HCl follows:
[tex]Mg(OH)_2+2HCl\rightarrow MgCl_2+2H_2O[/tex]
By Stoichiometry of the reaction:
2 moles of HCl reacts with 1 mole of magnesium hydroxide
So, 1.23 moles of HCl will react with = [tex]\frac{1}{2}\times 1.23=0.615mol[/tex] of magnesium hydroxide
As, given amount of magnesium hydroxide 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.
By Stoichiometry of the reaction:
2 moles of HCl produces 1 mole of magnesium chloride
So, 1.23 moles of HCl will produce = [tex]\frac{1}{2}\times 1.23=0.615mol[/tex] of magnesium chloride
- To calculate the theoretical yield of magnesium chloride we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Molar mass of magnesium chloride = 95.21 g/mol
Moles of magnesium chloride = 0.615 moles
Putting values in above equation, we get:
[tex]0.615mol=\frac{\text{Mass of magnesium chloride}}{95.21g/mol}\\\\\text{Mass of magnesium chloride}=(0.615mol\times 95.21g/mol)=58.6g[/tex]
Hence, the theoretical yield of magnesium chloride is 58.6 g
