Reactant a contains 85.1 j of chemical energy. reactant b contains 87.9 j of chemical energy. product c contains 38.7 j of chemical energy. if the reaction absorbs 104.3 j of chemical energy as it proceeds, how much chemical energy must product d contain?

238.6 J

Explanation:

1) Chemical energy is indicated as enthalpy

2) Energy balance:

∑ enthalpy of the reactants + energy added = ∑ enthalpy of the products + energy released.

3) ∑ enthalpy of the reactants = 85.1 J + 87.9 J = 173 J

4) energy added = 104.3 J

5) ∑ enthalpy of the products = 38.7 J + D

6) energy released = 0

7) Equation:

173J + 104.3J = 38.7 + D + 0

⇒ D = 173J + 104.3J - 38.7J = 238.6J, which is the chemical energy of the product D.

the answer is d. 74.02