Question

Oxides of P and Q are dissolved in water. They are tested with red cabbage juice
and phenolphthalein indicator respectively. Pink colour is obtained in both
cases. Identify P and Q:
A. Pis phosphorous and Q is sulphur
B. Pis phosphorous and Q is potassium
C. Pis potassium and Q is phosphorous
D. P is magnesium and Q is sodium​

Answer 1

Answer:

First off, if pink colour is shown in phenophthalein, always remember that it is BASIC. And if pink colour is shown in red cabbage leaves, then it is ACIDIC. With this in mind, try solving the question.

Given, P is tested with red cabbage leaves, and it shows pink colour, which means that P is ACIDIC.

Q is tested with phenophthalein, and shows pink colour, which means Q is BASIC.

Now, you might have learnt that metal oxides are basic and non metallic oxides are acidic.

This means that P is got to be phosphorus and Q is got to be potassium.

Your answer, is option B, P is phosphorous and Q is potassium.

Honestly, this question is very good. I learnt this when I was in grade 10!