Question

Temperature dependence of vacancy concentrations. Write a computer program that will provide a user with the equilibrium concentration of vacancies in a metallic element as a function of temperature. The user should specify a meaningful and valid range of temperatures (e.g., 100 to 1200 K for copper). Assume that the crystal structure originally specified is valid for this range of temperatures. Ask the user to input the activation energy for the formation of one mole vacancies (Qᵥ).

Answer 1

To calculate the enthalpy and entropy change of copper when cooled, use heat capacity and the change in temperature to find enthalpy change, then divide by temperature for entropy change.

Step-by-step explanation:

The question relates to the calculation of the change in enthalpy and entropy for a given amount of a metallic element as its temperature changes. In this case, we're looking at a 5.00 mole quantity of copper cooling from 100°C to 0°C. The heat capacity of copper is given as 38.5 J K-1 mol-1, which is assumed to be independent of temperature within the given range.

To calculate the enthalpy change (ΔH), we use the formula ΔH = m•c•ΔT, where m is the number of moles, c is the heat capacity, and ΔT is the change in temperature. The entropy change (ΔS) can be calculated using the relation ΔS = ΔQ/T, where ΔQ is the same as the calculated ΔH (at constant pressure) and T is the temperature in kelvins.