Question

Write the chemical equation of the reaction with an example each

in which the following change have taken place :

(i) Change in colour

(ii) Change in temperature​

Answer 1

1) CuSO4 + H2O-------> CuSO4.5H20

2)CaO + H2O -----------> Ca (OH)2 + heat.

HOPE IT HELPS

ADIOS

Answer 2

Answer :

(i) Change in colour : Reaction between lead nitrate solution and potassium iodide solution.

Pb(NO3)2 + 2KI ----) PbI2 + 2KNO3

In this, reaction colour changes from colourless to yellow.

(ii) Change in temperature : Action of dil. sulphuric acid on zinc.

Zn(s) + H2SO4(aq) ----) ZnSO4(aq) + H2

(iii) Formation of precipitate : Action of barium chloride on sodium sulphate.

BaCl2(aq) + Na2SO4(aq) ----) BaSO4(s) + 2NaCl(aq)