Chemistry · Oct / Nov 2017 · Paper 11 · Question 25

Nitrogenous fertilisers can cause eutrophication to occur in rivers. Eutrophication involves the five stages listed. 1 The fertiliser is washed into the river. 2 Oxygen levels become depleted in the river. 3 Plants die. 4 Plants begin to decay. 5 Plants in the river grow at an increased rate. In which order do these five stages occur during eutrophication?

1. A1 2 4 3 5
2. B1 2 5 4 3
3. C1 5 2 3 4
4. D1 5 3 4 2

As printed in the paper