DP Chemistry (last assessment 2024)
Question 18M.2.sl.TZ2.2d
| Date | May 2018 | Marks available | [Maximum mark: 1] | Reference code | 18M.2.sl.TZ2.2d |
| Level | sl | Paper | 2 | Time zone | TZ2 |
| Command term | Outline | Question number | d | Adapted from | N/A |
d.
[Maximum mark: 1]
18M.2.sl.TZ2.2d
Graphing is an important tool in the study of rates of chemical reactions.
(d)
Outline why H3PO4/HPO42− is not a conjugate acid-base pair.
[1]
Markscheme
«species» do not differ by a «single» proton/H+
OR
conjugate base of H3PO4 is H2PO4– «not HPO42–»
OR
conjugate acid of HPO42– is H2PO4– «not H3PO4»
Do not accept “hydrogen/H” for “H+/proton”.
[1 mark]
