Q1: Kopp's rule is helpful in finding the

ANS:A - heat capacities of solids.

Kopp's rule is primarily helpful in finding the heat capacities of solids. It's a rule that states that the molar heat capacity of a compound can often be approximated by adding together the atomic heat capacities of its constituent elements, weighted by their relative atomic fractions. This rule is particularly useful for solids, where the constituent atoms are typically closely packed and interact strongly with each other, leading to additive behavior of their heat capacities. While Kopp's rule is not directly applicable to gases or the determination of activation energy, there are analogous principles and rules that apply to those contexts. For gases, the heat capacities are often described using empirical formulas or derived from statistical mechanics principles. Activation energy, on the other hand, is a concept related to chemical kinetics and is determined through experimental methods such as Arrhenius equation fitting.