Question

Calculate the enthalpy change for the reaction: 3 NO���(g) + H���O(l) ��� 2 HNO���(aq) + NO(g) + 2 NO(g) + O���(g) ��� 2 NO���(g).

Answer 1

The enthalpy change for the reaction

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g)

is calculated by summing the enthalpy changes of the given steps, resulting in a total enthalpy change of -138.4 kJ.

Step-by-step explanation:

To calculate the enthalpy change for the reaction

3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g),

we need to sum the enthalpy changes of the individual steps provided:

ΔHrxn = ΔH1 + ΔH2 + ΔH3 + ΔH4

According to the information given, this sum is (−99.6 kJ) + (+285.8 kJ) + (∓414.8 kJ) + (+90.2 kJ). Calculating this we get:

ΔHrxn = −138.4 kJ

Thus, the enthalpy change for the given reaction is −138.4 kJ.