Question

Suggest a reason for each observation given below.
i) In fireworks, powdered magnesium is used rather than magnesium ribbon.
ii) Zinc and dilute H2
SO4
react much more quickly when a few drops of copper sulphate
solutions are added.
iii) The reaction between magnesium carbonate and dilute hydrochloric acid speeds
up when some concentrated HCl is added.

Answer 1

Magnesium powder or flash powder is used because it is easy to mix powder form of the metal with other chemicals like sulphur.

Flash powder is known to give illumination upon oxidation

ii) When a few drops of copper sulphate solution is used with zn and sulphuric acid then the reaction between zinc and sulphuric acid becomes strong, copper in the solution acts as a catalyst in the reaction.

iii) Concentrated HCl is a strong acid and when it is used in a reaction (Magnesium carbonate +dilute Hcl) then the acid makes the solution concentrated as water is produced as a result of the reaction between MgCO3+Hcl. The presence of water in the solution dilutes the Hcl reducing its strength.

Answer 2

I hope this helps you....