Date | May 2019 | Marks available | 1 | Reference code | 19M.1.sl.TZ2.19 |
Level | SL | Paper | 1 | Time zone | TZ2 |
Command term | Question number | 19 | Adapted from | N/A |
Question
What is the pH of 0.001 mol dm−3 NaOH (aq)?
A. 1
B. 3
C. 11
D. 13
Markscheme
C
Examiners report
The question discriminated well between high scoring and low scoring candidates. 58 % of the candidates were able to calculate the pH of the aqueous solution of NaOH. The most commonly chosen distractor was B (pH = 3) where the students determined pOH but did not complete the calculation. It is interesting that these candidates did not seem to notice that NaOH is a base and should have a higher pH.