DP Chemistry (first assessment 2025)
Question 19M.1A.HL.TZ2.26
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.1A.HL.TZ2.26 |
| Level | HL | Paper | 1A | Time zone | TZ2 |
| Command term | Question number | 26 | Adapted from | N/A |
26.
[Maximum mark: 1]
19M.1A.HL.TZ2.26
Where is the buffer region for the titration of a weak acid with a strong base?
[1]
Markscheme
B
Examiners report
There was a mistake on this question and it had to be annulled (39 marks paper). Grade boundaries were lowered accordingly. The x-axis was incorrectly labelled as “volume of weak acid” instead of “volume of strong base”. We sincerely apologize for this mistake which will be corrected before publication.
Syllabus sections
Reactivity 3. What are the mechanisms of chemical change? » Reactivity 3.1—Proton transfer reactions » Reactivity 3.1.13—pH curves of different combinations of strong and weak monoprotic acids and bases have characteristic shapes and features. Interpret the general shapes of pH curves for all four combinations of strong and weak acids and bases.