ANS:B - Kopp's rule

The heat capacity of a solid compound is calculated from the atomic heat capacities of its constituent elements with the help of Kopp's rule. Kopp's rule states that the molar heat capacity of a solid compound can be approximated as the sum of the products of the atomic heat capacities of its constituent elements and their respective atomic proportions in the compound. Therefore, the correct answer is: Kopp's rule. Kopp's rule is a heuristic rule used in chemistry to estimate the molar heat capacity of a solid compound based on the heat capacities of its constituent elements. It was formulated by the German chemist Hermann Kopp in the 19th century. The rule states that the molar heat capacity (𝐶C) of a solid compound can be approximated as the sum of the products of the atomic heat capacities (𝐶𝑖Ci​) of its constituent elements and their respective atomic proportions (𝑥𝑖xi​) in the compound: 𝐶compound=∑𝑖𝑥𝑖⋅𝐶𝑖Ccompound​=∑i​xi​⋅Ci​ Where:

• 𝐶compoundCcompound​ is the molar heat capacity of the compound,
• 𝑥𝑖xi​ is the atomic proportion of element 𝑖i in the compound,
• 𝐶𝑖Ci​ is the atomic heat capacity of element 𝑖i.

Kopp's rule is based on the assumption that the heat capacity of a solid compound can be estimated by considering the individual contributions of its constituent elements. It assumes that the atoms or ions in the compound behave independently and contribute additively to the overall heat capacity of the compound. While Kopp's rule provides a convenient method for estimating the heat capacity of solid compounds, it is an approximation and may not always yield accurate results. Factors such as chemical bonding, crystal structure, and interactions between atoms in the compound can influence the actual heat capacity and may lead to deviations from the predicted values. Nonetheless, Kopp's rule remains a useful tool for estimating heat capacities, particularly for simple compounds with well-defined structures.