Question

Given the following reactions 2no → n2 o2 δ h = -180 kj 2no o2 → 2no2 δ h = -112 kj the enthalpy of the reaction of nitrogen with oxygen to produce nitrogen dioxide n2 2o2 → 2no2 is ________ kj.

Answer 1

Using Hess's Law, the reaction N2+2O2 → 2NO2 has an enthalpy change of +68 kJ, which is calculated by reversing and combining two given reactions.

Step-by-step explanation:

To calculate the enthalpy of the reaction of nitrogen (N2) with oxygen (O2) to produce nitrogen dioxide (NO2), we can use Hess's Law, which states that the total enthalpy change for a reaction is the sum of the enthalpy changes for each step of the reaction.

Based on the provided reactions:

• 2NO → N2+O2 ΔH = -180 kJ
• 2NO + O2 → 2NO2 ΔH = -112 kJ

To find the enthalpy change for N2+2O2 → 2NO2, we have to reverse the first reaction and add it to the second reaction. By reversing the first reaction, we change the sign of the enthalpy change from -180 kJ to +180 kJ.

Reversed reaction:
N2+O2 → 2NO ΔH = +180 kJ

Then add it to the second reaction:
2NO+O2 → 2NO2 ΔH = -112 kJ
N2+2O2 → 2NO2 ΔH = +68 kJ

The enthalpy for the reaction of nitrogen with oxygen to produce nitrogen dioxide is +68 kJ.