Question

Calculate the enthalpy of solution (∆H) for the dissolution) per mole of NH₄NO₃ under the conditions described in example 5.6.

Short answer

The enthalpy of a solution (∆H for dissolution) per mole of NH₄NO₃is 25 kJ/mol.

Step-by-step solution

Given data

• The given mass of NH₄NO₃is 3.21g.
• The heat of the reaction is q= +1.0 kJ (from example 5.6).

Calculation of enthalpy of the solution

The number of moles of NH₄NO₃ is calculated as:

\begin{aligned}Numberofmoles=\frac{{3.21g}}{{80.043g/mol}}\\=0.04mol\end{aligned}

Therefore, the enthalpy of the reaction can be determined by the formula:

Enthalpy = Heatofthereaction(q)/no.of moles

The known values are substituted:

\begin{aligned}enthalpy=\frac{{1.0kJ}}{{0.04mol}}\\=25kJ/mol\end{aligned}

Hence, ∆H = 25 kJ/mol.