Question 19M.2.hl.TZ2.4c
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.2.hl.TZ2.4c |
| Level | hl | Paper | 2 | Time zone | TZ2 |
| Command term | Describe | Question number | c | Adapted from | N/A |
Rhenium, Re, was the last element with a stable isotope to be isolated.
Before its isolation, scientists predicted the existence of rhenium and some of its properties.
Describe how the relative reactivity of rhenium, compared to silver, zinc, and copper, can be established using pieces of rhenium and solutions of these metal sulfates.
[2]
place «pieces of» Re into each solution [✔]
if Re reacts/is coated with metal, that metal is less reactive «than Re» [✔]
Note: Accept other valid observations such as “colour of solution fades” or “solid/metal appears” for “reacts”.
Many candidates chose to set up voltaic cells and in other cases failed to explain the actual experimental set up of Re being placed in solutions of other metal salts or the reaction they could expect to see.
