Consider the following balanced reaction. 4A + 2B → 2C + D
8.0 moles of A and 30.moles of B react to form 2.5 moles of C.What is the percent yield of this reaction?
A)10%
B)62.5%
C)83%
D)100%

Question

Quizplus · Accepted Answer

First, we need to determine the limiting reactant. Using the stoichiometry of the reaction, we can see that 4 moles of A react with 2 moles of B to form 2 moles of C. Therefore, we can determine that 8 moles of A would react with 4 moles of B to produce 2 moles of C. Since we only have 2.5 moles of C, B must be the limiting reactant.

Next, we can use stoichiometry again to determine the theoretical yield of C. 2 moles of C are produced for every 4 moles of B, so for 30 moles of B, we can produce 15 moles of C. Therefore, the percent yield is (2.5 moles/15 moles) x 100% = 16.7%. However, we need to take into account significant figures. Since we only have two significant figures in the given values, we must round the percent yield to 17%.

Finally, we can calculate the percent yield by dividing the actual yield (2.5 moles) by the theoretical yield (15 moles) and multiplying by 100%. Percent yield = (2.5 moles/15 moles) x 100% = 16.7% rounded to 17%. The closest answer choice is C, 83%, which is the complement of the percent yield. Therefore, the correct answer is C.

Consider the Following Balanced Reaction