Q.7. What happens when potassium iodide solution is added to lead nitrate solution? Give equation of the reaction involved. What type of reaction is represented by this example? (3marks)
Ans. When potassium iodide solution is added to lead nitrate solution, then a yellow
precipitate of lead iodide is formed alongwith potassium nitrate solution
Pb(NO3)2 (aq) + 2KI (aq) PbI2 (S) + 2 KNO3 (aq)
This is an example of a double displacement reaction. It is also a precipitation
Q.8. When a green iron salt is heated strongly, its colour finally changes to black and the odour of burning sulphur is given out.
a) Name the iron salt.