Practical Work — CHEMISTRY STD 9 — Question

Define the term: Element

Identify the gases from the observations:
A colourless gas, which changes to steamy vapours on cooling. It forms colourless, tiny droplets of liquid which turn anhydrous copper sulphate blue and anhydrous cobalt chloride pink.

Write the balanced chemical equation of the following reaction.
Potassium permanganate + hydrochloric acid → potassium chloride + manganese chloride + chlorine + water

In which part of a group would you separately expect the elements to havethe greatest metallic character

Name or state the following:

Elements having same mass number but different atomic number

Name and state the following with reference to the elements of the first three periods of the periodic table.
Non-metallic elements present in Period 3 of Groups 15 and 16.

Name a compound which produces carbon dioxide on heating.

Name four alkali metals. To which group do they belong?

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