I am very confused on this problem. Any help would be great:
50 g of silver nitrate is mixed with 50 g of hydrochloric acid in a water-based solution. A white precipitate forms (silver chloride.) The solution is filtered and the white precipitate collected and dried. The dried precipitate is measured to have a mass of 33.6 g. What is the theoretical and percent yield?
Thanks so much for helping me with this. :)
First, start with a balanced equation. Then, use stoichiometry to determine the limiting reactant and then how much product (AgCl) is produced. Use this (theoretical yield) and the actual yield (33.6g) to determine the percent yield.
Thank you very much, David. I understand it now :D
To find the theoretical and percent yield, let's break down the problem step by step:
Step 1: Write the balanced chemical equation:
AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq)
Step 2: Calculate the molar mass of each compound:
AgNO3: Ag (107.87 g/mol) + N (14.01 g/mol) + O (3 * 16.00 g/mol) = 169.87 g/mol
HCl: H (1.01 g/mol) + Cl (35.45 g/mol) = 36.46 g/mol
AgCl: Ag (107.87 g/mol) + Cl (35.45 g/mol) = 143.32 g/mol
Step 3: Calculate the molar amount of reactants used:
50 g AgNO3 * (1 mol AgNO3 / 169.87 g AgNO3) = 0.294 mol AgNO3
50 g HCl * (1 mol HCl / 36.46 g HCl) = 1.37 mol HCl
Step 4: Determine the limiting reactant:
To find the limiting reactant, we compare the mole ratio of AgNO3 to HCl in the balanced equation. The ratio is 1:1, so the reactant with a smaller amount used is the limiting reactant. In this case, AgNO3 is the limiting reactant because we used less of it.
Step 5: Calculate the theoretical yield:
Theoretical yield = limiting reactant's molar amount * molar mass of the desired product
Theoretical yield = 0.294 mol AgNO3 * (1 mol AgCl / 1 mol AgNO3) * 143.32 g/mol AgCl
Theoretical yield = 12.95 g AgCl
Step 6: Calculate the percent yield:
Percent yield = (actual yield / theoretical yield) * 100
Percent yield = (33.6 g AgCl / 12.95 g AgCl) * 100
Percent yield = 259.08%
Since the percent yield is greater than 100%, it suggests that there might be an error in the experimental procedure. The actual yield obtained is higher than the theoretical yield, which is not possible in a real-world scenario. Therefore, you should check your experimental procedure to identify any potential sources of error.
Note: In cases where the percent yield is greater than 100%, it's common to assume that the experimental measurement is inaccurate or some additional impurities may be present in the product.