The Language of Chemistry — CHEMISTRY STD 9 — Question

In which of the following substances will there be
No change in mass when they are exposed to air?
Sodium chloride
Iron
Conc. sulphuric acid
Table salt
Sodium carbonate crystals

Name and state the following with reference to the elements of the first three periods of the periodic table.
Typical elements of Groups 14 and 15.

How many electrons do inert gases have in their valence shells?

Write the balanced chemical equation of the following reaction.
potassium bicarbonate + sulphuricacid → potassiumsulphate+carbon dioxide+water

Identify the gases from the observations:
A colourless gas having a rotten eggs like smell. It turns limewater milky and moist lead acetate paper silvery black.

Give an example of the following chemical change.
Two solids combine to form a liquid

Give an example of a reaction where the following is involved .
Evolution of heat

Give reason for the following:
Silver nitrate solution is kept in coloured bottles.