In a chemical reaction, A and B reacts to form D. C is the intermediate product of this reaction. Percent yield of the reaction A+B->C is 50% and the percent yield of the reaction C->D is 90%. How many moles of D can be produced when 14 moles of A and B react?

The long way:

14 mols A and 14 mols B will produce 14*0.50 = 7 mols C.
Then C will produce 7*0.9 = 6.3 mols D.

The short way:
overall yield is 0.5*0.9 = 0.45 or 45%.
14*0.45 = 6.3

To solve this problem, we need to break it down into two steps and calculate the yields separately.

Step 1: Calculate the moles of C produced.
Given that the percent yield of the reaction A + B -> C is 50%, we can calculate the moles of C produced using the following equation:

Moles of C = Moles of A + B * Percent yield of A + B -> C

Since we are given that 14 moles of A and B react, we can substitute this value into the equation:

Moles of C = 14 moles * 50% = 7 moles

Step 2: Calculate the moles of D produced.
Given that the percent yield of the reaction C -> D is 90%, we can calculate the moles of D produced using the following equation:

Moles of D = Moles of C * Percent yield of C -> D

Substituting the value we calculated for Moles of C:

Moles of D = 7 moles * 90% = 6.3 moles

Therefore, 6.3 moles of D can be produced when 14 moles of A and B react.