DP Chemistry (last assessment 2024)

Test builder »

Question 19M.1.hl.TZ2.23

Select a Test
Date May 2019 Marks available [Maximum mark: 1] Reference code 19M.1.hl.TZ2.23
Level hl Paper 1 Time zone TZ2
Command term Question number 23 Adapted from N/A
23.
[Maximum mark: 1]
19M.1.hl.TZ2.23

Iodine and bromine gases were mixed and allowed to reach equilibrium.

What is the value of the equilibrium constant?

A. 0.05

B. 1

C. 4

D. 10

[1]

Markscheme

C

Examiners report

This was a challenging question with the highest discrimination index on the paper. 62 % of the candidates were able to deduce the equilibrium concentration of IBr and calculate the equilibrium constant correctly. The most commonly chosen distractor was B where the stoichiometric ratio was not taken into account when calculating the equilibrium concentration of IBr.

Syllabus sections