Question

The enthalpy change for the reaction \( \text{N}_2(g) + 3\text{H}_2(g) \rightarrow 2\text{NH}_3(g) \) is \( -92.4 \, \text{kJ/mol} \). What is the enthalpy change when 4 moles of nitrogen react?

• A. \( -92.4 \, \text{kJ} \)
• B. \( -184.8 \, \text{kJ} \)
• C. \( -46.2 \, \text{kJ} \)
• D. \( -368.4 \, \text{kJ} \)

Hint:

Remember: The enthalpy change is directly proportional to the amount of reactant in the reaction.

Answer 1

The Correct Option is B

Given: The enthalpy change for the reaction is \( -92.4 \, \text{kJ/mol} \) for 1 mole of nitrogen. We need to find the enthalpy change for 4 moles of nitrogen. 

Use the proportionality The reaction involves 1 mole of nitrogen, so for 4 moles of nitrogen, the enthalpy change will be: \[ \text{Enthalpy change} = 4 \times (-92.4) = -184.8 \, \text{kJ} \] 

Answer: The correct answer is option (2): \( -184.8 \, \text{kJ} \).