DP Chemistry (first assessment 2025)

Question 19M.1A.SL.TZ2.18

18.

[Maximum mark: 1]

19M.1A.SL.TZ2.18

What is the equilibrium constant expression for the following equation?

2NO₂ (g) + F₂ (g) $\rightleftharpoons$ 2NO₂F (g)

A. $\frac{{2[{\text{N}}{{\text{O}}_2}{\text{F]}}}}{{2[{\text{N}}{{\text{O}}_2}] + [{{\text{F}}_2}]}}$

B. $\frac{{2[{\text{N}}{{\text{O}}_2}{\text{F]}}}}{{2[{\text{N}}{{\text{O}}_2}][{{\text{F}}_2}]}}$

C. $\frac{{{{[{\text{N}}{{\text{O}}_2}{\text{]}}}^2}{\text{[}}{{\text{F}}_2}{\text{]}}}}{{{{[{\text{N}}{{\text{O}}_2}{\text{F}}]}^2}}}$

D. $\frac{{{{[{\text{N}}{{\text{O}}_2}{\text{F]}}}^2}}}{{{{[{\text{N}}{{\text{O}}_2}]}^2}[{{\text{F}}_2}]}}$

[1]

Markscheme

Examiners report

One of the easiest questions on the paper. 89 % of the candidates chose the correct Kc expression.

Syllabus sections