Find $\Delta n$ when 1 mol of each $\text{NH}_{3(g)}$ and $\text{HCl}_{(g)}$, reacts to form solid $\text{NH}_4\text{Cl}$.

Question

The enthalpy change for the reaction $ \text{C} + \text{O}_2 \rightarrow \text{CO}_2 $ is $ -393.5 \, \text{kJ/mol} $. What is the heat released when 2 moles of carbon react with excess oxygen?

Answer 1

Step 1: Rule
Only gas-phase species enter $\Delta n$.

Step 2: Count
Reactant gases: NH3 (1) and HCl (1), total 2. Product gases: none, since NH4Cl is solid.

Step 3: Result
$\Delta n = 0 - 2 = -2$, option (B).

Final Answer:
Option (B). \[ \boxed{-2} \]

Find \(\Delta n\) when 1 mol of each \(\text{NH}_{3(g)}\) and \(\text{HCl}_{(g)}\), reacts to form solid \(\text{NH}_4\text{Cl}\).

Show Hint

The Correct Option is B

Solution and Explanation

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