Question 22N.2.hl.TZ0.1c.v
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.2.hl.TZ0.1c.v |
| Level | hl | Paper | 2 | Time zone | TZ0 |
| Command term | Justify, State | Question number | c.v | Adapted from | N/A |
Ammonium nitrate, NH4NO3, is used as a high nitrogen fertilizer.
A 0.20 mol dm−3 solution of ammonium nitrate is prepared.
State, with a reason, if bromothymol blue is an appropriate indicator for this titration. Use section 22 of the data booklet.
[1]
no AND the end point is not in the sharp part of the curve
OR
no AND the equivalence point does not fall within the end-point/pH range of the indicator
OR
no AND there is a large difference in volume between end point and equivalence point
OR
no AND no sharp rise in pH «near equivalence point» ✔
Just over half the candidates managed to correctly assess whether bromothymol blue would be act as an effective indicator for the titration curve they had drawn. From the ranges quoted, many students seem to have read bromophenol blue rather than bromothymol blue.
