Sometimes fluorine contains impurity of $HF$. It can be removed by passing it through Sodium fluoride.The reaction occured in this process is:

Q. HF is present as an impurity in gaseous fluorine. It can be removed by passing over:

Q. It is sometimes necessary to remove colouring matter contained as an impurity in glass. Glass is decolourised by:

Q.

In laboratory preparation of hydrogen, impurities of arsine and phosphine can be removed by passing it through which of the following solution?

Q. The salt we get from sea water can have many impurities in it. These impurities can be removed by :

Q. Chromium - plated steel is a material of popular use. During its process of manufacture, the effluent contains chromate and cyanide ions as impurities. After these are chemically removed, carbon dioxide and salt (sodium chloride) still remain as impurities. This salt solution is purified electrolytically by adding carbonaceous matter which acts as: