31.

What would you observe in the following case?

Sugar crystal is added to a hard glass test tube containing concentrated sulphuric acid.

What happens to the crystals of washing soda when exposed to air? Name the phenomenon exhibited.

What would you observe in the following case?

Ammonium hydroxide is first added in a small quantity and then in excess to a solution of copper sulphate.

Write the balanced chemical equation for the following reaction:

Zinc is heated with sodium hydroxide solution.

Write balanced chemical equation for the following:

Zinc oxide dissolves in sodium hydroxide

Calculate the volume of 320g of SO₂ at stp.(atomic mass : S=32 and O=16)

State Gay-Lussac’s law of combining volumes.

Calculate the volume of oxygen required for the complete combustion of 8.8g of propane (C₃H₈).

An organic compound with vapour density=94 contains C =12.67%, H=2.13% and Br=85.11%. Find the molecular formula,[Atomic mass: C=12, H=1, Br=80]

Calculate the mass of :

i)  10²²atoms of sulphur

ii) 0.1 Mole of carbon dioxide

[Atomic mass : S =32.C=12 and O =16 and Avogadro's number=6x10²³]