For the reaction 2 SO2(g) + O2(g) ⇌ 2 SO3(g), what is the value of Δn (the change in moles of gas) used when relating Kc to Kp?

• A. Δn = 0
• B. Δn = -1
• C. Δn = +1
• D. Δn = +2

Answer: (B)

Verified step by step guidance

1. Identify the balanced chemical equation: \$2 \mathrm{SO_2}(g) + \mathrm{O_2}(g) \rightleftharpoons 2 \mathrm{SO_3}(g)$.
2. Determine the total moles of gaseous reactants by adding their coefficients: \$2 + 1 = 3$ moles of gas on the reactant side.
3. Determine the total moles of gaseous products by adding their coefficients: \$2$ moles of gas on the product side.
4. Calculate the change in moles of gas, \(\Delta n\), using the formula: \(\Delta n = \text{moles of gaseous products} - \text{moles of gaseous reactants}\).
5. Substitute the values: \(\Delta n = 2 - 3\), which gives the change in moles of gas used when relating \(K_c\) to \(K_p\).