Question

What happens when a piece of
(a) zinc metal is added to copper sulphate solution?
(b) aluminium metal is added to dilute hydrochloric acid?
(c) silver metal is added to copper sulphate solution?
Also, write the balanced chemical equation if the reaction occurs

NCERT Class X
Science - Exemplar Problems

Chapter_Chemical Reactions And Equations

Answer 1

a)  Zinc  and  Copper Sulphate Cu SO₄  solution 
     as copper is less electro positive than Zinc.  Zinc is more reactive than copper.
         Cu  :  29        Zn :  30
 Cu SO₄  blue solution + Zn powder  ==>  Cu  (red/brown powder) + Zn SO₄  colorless solution

b)  2 Al  + 6 H Cl    ==>  2  Al Cl₃  + 3 H₂
         Aluminum is more electro positive than Hydrogen...
       So Aluminum is more ready to lose electron..

c)    Ag  +  Cu SO₄   === >    No reaction.... as  Silver is less reactive than copper.

Answer 2

(a)    When zinc metal is added to copper sulphate solution, the colour of CuSO4 solution disappears and colourless zinc sulphate solution is formed. Solid brown copper is deposited as it displaces by Zn.

Zn + CuSO4---------> ZnSO4 + Cu

(b) Aluminium displaces hydrogen from HCl and hydrogen gas is evolved with soluble aluminium chloride.

2Al + 6HCl ---------->  2AlCl3 + 3H2

(c) Silver is a Nobel metal and does not exhibit any reaction with copper sulphate.