Answer:
[tex]n_{MgCl_2}=3.43mol MgCl_2[/tex]
Explanation:
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In this case, since the reaction between magnesium and hydrochloric acid is:
[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]
Whereas there is a 1:1 and 1:2 mole ratio between magnesium and magnesium chloride and hydrochloric acid and magnesium chloride respectively; it is possible to compute the yielded moles of product by each reactant and then determine which moles are correct based on the limiting reactant; therefore, we proceed as follows:
[tex]n_{MgCl_2}^{by\ Mg}=4.39molMg*\frac{1molMgCl_2}{1molMg} =4.39molMgCl_2\\\\n_{MgCl_2}^{by\ HCl}=250.0gHCl*\frac{1molHCl}{36.46gHCl}*\frac{1molMgCl_2}{2molHCl}=3.43mol MgCl_2[/tex]
Thus, since the hydrochloric acid yields the fewest moles of product, we infer it is the limiting reactant, so the correct number moles of magnesium chloride are 3.43 mol.
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