Question

Why zn metal can't be directly used but zn and amalgam rod is used as electrode in electrochemical cell

Answer 1

Explanation:

First calculate the quantity of zinc required.

Let x be the total mass of amalgam.

Mass of mercury =0.75x=9g⟹x=12 g

Mass of zinc=0.25x=0.25×12g=3 g

Quantity of electricity passed=Q(C) = I (A) × t (s) = I (A) × 1000 s

The atomic weight of zinc is 65.4

mol

g

.

Moles of electrons passed

=

96500

mol e

−

C

Q(C)

=

96500

mol e

−

C

I (A) × 1000 s

The weight of zinc deposited,