Give reasons :
A candle brought near the mouth of a jar containing hydrogen gas starts burning but is extinguished when pushed inside the jar.

What happens when a burning splinter is brought near the mouth of a gas jar containing hydrogen gas?

Give a test to differentiate between two gas jars. One containing pure hydrogen and the other hydrogen air mixture.

A pop sound is heard when a lighted match stick is brought near the mouth of a jar. This indicates the release of gas.

An empty glass jar is submerged in tank of water with open mouth of the jar downwards, so that air inside the jar is trapped and cannot get out. As the jar is pushed down slowly, the magnitude of net buoyant force on the system of volume of gas trapped in the jar and the jar.

(i) You are provided with two test tubes containing an aqueous solution of carbonateand sulphite respectively. How will you identify them? (ii) A colourless salt on heating, forms a white sublimate on the cooler sides of the lost tube. The gas evolved is colourless and has a pungent smell. It givos donse white fumes when a rod dipped in conc. HCl is brought near the mouth of the fest tube. Identify the basic radical present in the salt.

Aluminium dissolves in mineral acids and aqueous alkalies and thus shows amphoteric character. A piece of aluminium foil is treated with diluted hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a buring matchstick near the mouth of the test tube, a pop sound indicates the volution of hydrogen gas. The same activity when performed with concentrated nitric acid, reaction doesn't proceed. Explain the reason.

What happens when a jar full of H_2 gas is placed inverted over a jar containing Cl_2 gas?

Give reasons for the following Dense white fumes are obained when a jar of HCl gas is inverted over a jar of ammonia gas.

When BeCl_(2) is hydrolysed, white fumes of gas are given out. The intensity of fumesintensifies when a rod dipped in moist ammonia is brought near the mouth of the test tube. The gas which comes out during hydrolysis is