Question

What happens when a strip of lead metal is placed in a solution of copper chloride? Write the balanced chemical equation for the reaction along with the colour changes observed during the reaction.Ii.What are precipitation reactions? Give one example of a precipitation reaction?

Answer 1

Copper chloride

Copper is a transition metal with valency +2 and +1 as variable valency.

Chloride is the negative radical with valency -1.

During formation of copper chloride, the copper shows it +2 valency , so two atoms of chloride radical reacts forming copper chloride .

Lead

Lead is the metal lies in middle of reactivity series but above copper so is more reactive than copper.

I) When copper chloride reacts with lead metal.

Observation :-

Green colour of copper chloride fades away leaving behind a white residue of lead chloride and a brown coating of copper metal.

Equation:-

$Pb + CuCl_2 \longrightarrow PbCl_2 + Cu$

II) Precipitation reaction

Reaction between two compounds or a compound and metal to form a new insoluble compound is called precipitation reaction.

Example :

$CaCl_2 + Na_2CO_3 \longrightarrow 2NaCl + CaCO_3$

Answer 2

Answer:

that ans. is. right