Final answer:
Given the reaction 5 A(aq) + 5 B(aq) → 5 C(aq) + 5 D(aq), if the concentration of D decreases by 0.015M, then the concentration of B should increase by 0.015M, due to the 1:1 molar relationship.
Step-by-step explanation:
The reaction 5 A(aq) + 5 B(aq) → 5 C(aq) + 5 D(aq) indicates that the molar ratio of reactants A and B to products C and D is 1:1. Therefore, the change in concentration for B should be equal to the change in concentration for D, but in the opposite direction because B is being used up in the reaction. In this instance, if the concentration of D decreases by 0.015M, there will be an increase in concentration of B by 0.015M. This is under the assumptions of constant temperature and volume and that the system is at equilibrium (Le Chatelier's principle).
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