Question

Answer the following in brief.

How many moles of electrons are passed when 0.8-ampere current is passed for 1 hour through molten CaCl₂?

Answer 1

Given:

Current (I) = 0.8 ampere,
Time (t) = 1 hour = 1× 60 × 60 s = 3600 s

To find:
No. of moles of electrons passed through molten CaCl₂

Formulae:

1. Quantity of electricity passed = I(A) × t(s)

2. No. of moles of electrons passed = `("Q"("C"))/(96500 ("C"//"mol"  "e"^-))`

Calculation: Using formula (i),

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

= 0.8 × 3600 = 2880 C

Using formula (ii),

No. of moles of electrons passed

`("Q"("C"))/(96500 ("C"//"mol"  "e"^-)) = (2880 "C")/(96500 ("C"//"mol"  "e"^-))` = 0.03 mol e^-

Number of moles of electrons passed through molten CaCl₂ is 0.03 mol e^–.