Question

Study the figure given below and mark the correct expression.

The enthalpy of solution$\left(\Delta H_{soln}^0\right)$ of $X{Y}_{\left(s\right)}$ in water can be determined by:

• A. $\Delta H_{lattice}^0=\Delta H_{hyd}^0+\Delta H_{soln}^0$
• B. $\Delta H_{hyd}^0=\Delta H_{lattice}^0+\Delta H_{soln}^0$
• C. $\Delta H_{soln}^0=\Delta H_{lattice}^0+\Delta H_{hyd}^0$
• D. $\Delta H_{soln}^0=\Delta H_{lattice}^{0}X\Delta H_{hyd}^0$

Answer 1

The correct option is C $\Delta H_{soln}^0=\Delta H_{lattice}^0+\Delta H_{hyd}^0$

Hess's Law of Constant Heat Summation (or just Hess's Law) states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of Enthalpy changes of all changes.

So, $\Delta H_{soln}^0=\Delta H_{lattiace}^0+\Delta H_{hyd}^0$

Hence, the correct answer is option $\text{C}$.