Question

reactant p contains 50 j of energy, and reactant q contains 35.3 j of energy. the reactants combine to form product pq, which contains 104 j of energy. what is the energy transformation?

• energy is absorbed because the product has more energy than the reactants have.
• energy is absorbed because the product has less energy than the reactants have.
• energy is lost because the product has more energy than the reactants have.
• energy is lost because the product has less energy than the reactants have.

Explanation:

1. First, calculate the total energy of reactants: \(50\space J + 35.3\space J = 85.3\space J\).
2. The product (PQ) has \(104\space J\) of energy. Since \(104\space J>85.3\space J\), the product has more energy than the reactants.
3. In a reaction, if the product has more energy than the reactants, energy is absorbed (endothermic process). So we check the options:

• Option 1: Says energy is absorbed as product has more energy than reactants. This matches our calculation.
• Option 2: Incorrect as product has more (not less) energy.
• Option 3: Incorrect, energy is absorbed (not lost) when product has more energy.
• Option 4: Incorrect, product has more energy and energy is absorbed, not lost.

Answer:

A. Energy is absorbed because the product has more energy than the reactants have.