Stoichiometry Reaction Problem.. Help? When 100ml of 1M solution B is combined with 100ml of a 1M solution D, the resulting solution has a concentration of 0.250M of A, 0.1250M of B, 0.3750M ofC and no more substance D remains. 1. How many moles of each B and D are present before the reaction occurs? 2. How many moles each of A, B, C, and D are present after the reaction occurs? 3. How many moles of B and B have reacted? 4. What is the balanced equation for this reaction?