The question involves stoichiometry and limiting reactant to determine the percent yield for the precipitation of magnesium ions. The chosen compound was the limiting reactant that would theoretically produce 2.360 grams of precipitate. The actual yield of 1.601 grams results in an approximately 67.8% percent yield, not the stated 49.6%.
The concept in question relates to stoichiometry and limiting reactant analysis in chemical reactions. Specifically, this involves determining which reactant will limit the amount of product formed in the reaction and then calculating the percent yield based on the actual amount of product obtained. The student is trying to precipitate magnesium ions (Mg2+) by adding another compound to induce precipitation and form a solid product, likely Mg(OH)2. The limiting reactant produces less product, and here, it's mentioned that the chosen compound is the limiting reactant as it would produce only 2.360 grams of precipitate, while Mg2+ if it were limiting would produce 2.073 grams.
To calculate the percent yield, the actual mass of precipitate isolated (1.601 g) is compared with the theoretical yield (2.360 g), given that the chosen compound is limiting. The percent yield is calculated using the formula: Percent Yield = (Actual Yield / Theoretical Yield) x 100%. Substituting the given values in, the percent yield would be (1.601 g / 2.360 g) x 100%, which equals approximately 67.8%, contrary to the erroneous statement of 49.6% provided by the student. This discrepancy suggests that either the initial information provided is incorrect, or there was a miscalculation in deriving the percent yield. When approached with such questions, a student must reconcile the theoretical and actual values to accurately determine the efficiency of the chemical reaction.