Question

How many atoms of calcium will be deposited from molten cacl2 bind a current of 25 milli amperes flowing for 60 seconds?

Answer 1

Answer:

Number of atoms of Ca deposited = 468.7 × 10¹⁶ atoms

Explanation:

Given data:

Charge = 25 mA  (25×10⁻³ amp)

Time = 60 sec

Number of atoms deposited = ?

Solution:

First of all we will write the equation:

Ca²⁺ +2e →  Ca

Formula,

q = ne

25×10⁻³×60 = n× 1.6×10⁻¹⁹

n = 25×10⁻³ ×60/ 1.6×10⁻¹⁹

n = 937.5 × 10¹⁶

Number of moles of electrons = 937.5 × 10¹⁶ / 6.02 × 10²³

Number of moles of electrons = 155.7 × 10⁻⁷ moles

Number of moles of Ca deposited = 155.7 × 10⁻⁷/ 2

Number of moles of Ca deposited = 77.85 × 10⁻⁷ moles

number of atoms of Ca deposited = 77.85 × 10⁻⁷×6.02 × 10²³

number of atoms of Ca deposited = 468.7 × 10¹⁶ atoms