Question

which of the statements is a consequence of the first law of thermodynamics? the entropy of the products of a reaction is always greater than the entropy at the start of the reaction. the amount of useable energy resulting from a reaction is always less than the total energy available at the start of a reaction. the entropy at the start of a reaction is always greater than the entropy of the products. the energy at the start of a reaction equals the sum of the energy in the product plus energy released as heat and disorder.

Explanation:

The first law of thermodynamics is the law of conservation of energy. It states that energy cannot be created or destroyed, only converted from one form to another. So the total energy at the start of a reaction must equal the sum of the energy in the products plus any energy released as heat and other forms. Entropy - related statements are related to the second law of thermodynamics. The statement about usable energy being less is related to the concept of energy quality and the second - law implications.

Answer:

The energy at the start of a reaction equals the sum of the energy in the product plus energy released as heat and disorder.