To determine how much energy would be absorbed if 26.3 grams of ammonium chloride (NH₄Cl) reacts, we need to follow these steps:
1. Determine the number of moles of NH₄Cl:
- The molar mass of NH₄Cl (ammonium chloride) is given as 53.49 g/mol.
- The mass of NH₄Cl is given as 26.3 grams.
- We use the formula for the number of moles:
[tex]\[
\text{moles of NH}_4\text{Cl} = \frac{\text{mass of NH}_4\text{Cl}}{\text{molar mass of NH}_4\text{Cl}}
\][/tex]
[tex]\[
\text{moles of NH}_4\text{Cl} = \frac{26.3\text{ g}}{53.49\text{ g/mol}}
\][/tex]
Calculating this gives:
[tex]\[
\text{moles of NH}_4\text{Cl} \approx 0.4917 \text{ mol}
\][/tex]
2. Determine the energy absorbed:
- The enthalpy change [tex]$\Delta H$[/tex] for the reaction is given as 54.8 kJ per mole of the reaction.
- Since the balanced chemical equation shows that 2 moles of NH₄Cl are involved in the reaction, we need to find the energy absorbed for the moles of NH₄Cl we calculated.
- We use the formula to calculate the energy absorbed:
[tex]\[
\text{Energy absorbed} = \text{moles of NH}_4\text{Cl} \times \Delta H
\][/tex]
[tex]\[
\text{Energy absorbed} = 0.4917 \text{ mol} \times 54.8\text{ kJ/mol}
\][/tex]
Calculating this gives:
[tex]\[
\text{Energy absorbed} \approx 26.9441 \text{ kJ}
\][/tex]
Therefore, if 26.3 grams of NH₄Cl reacts, approximately 26.9441 kJ of energy would be absorbed.
