Question

a colourless solution of potassium iodide and lead acetate are mixed when a coloured precipitate is formed. Answer the following;
i) What kind of chemical reaction takes place
ii) Write a balanced chemical equation for the reaction
iii) What is the formula and colour of precipitate

Answer 1

1) It is double displacement reaction.
2)Pb(NO3)2+2KI=PbI2+2KNO3
3)That precipitation is brownish yellow in colour. And its formula is PbI2

Answer 2

i) Double displacement reaction is the chemical reaction that takes place.

ii) A balanced chemical equation for the reaction is:

            Pb (NO₃)₂(aq)  +  2KI(aq) → PbI₂(s)↓  +   2KNO₃   (aq)  

iii)  The color of the precipitate is yellow and its formula is  PbI₂ (lead iodide).

On adding lead nitrate to potassium iodide, the reaction forms two compounds. One is lead iodide which changes into yellow precipitation and the other is potassium nitrate. The yellow color of the precipitate is due to the weak reducing property of potassium iodide.

The reaction is double displacement because two compounds react in such a way that the ions of two compounds are exchanged mutually to form two different compounds and can be shown as,

        [XY   +    AB    →       XB    +    AY]

#SPJ3