11.2 Alkanes — Chemistry STD 10 — Question

If a solution changes the colour of litmus from red to blue, what can you say about its pH?

Impurities which remain behind at the bottom of the cell.

Write a balanced equation for following :
Action of cold and dilute nitric acid on copper

Electrode used as cathode in electrorefining of impure copper.

Identify the substance underlined, in the following case: A solid formed by reaction of two gaes, one of which is acidic and the other basic in nature.

Give two examples of the following:
dibasic acid

Write the equation for the laboratory preparation of the following salts, using sulphuric acid.
Lead sulphate from lead nitrate.

Name the solution used to react with Bauxite as a first step in obtaining pure aluminium oxide in the Baeyer's process.

What is aqua-regia?

The formula of slag.