Question

A salt QCl of a certain metal Q is electrolyzed to its elements. 40 g of metal Q is formed at an electrode. The volume of Cl₂ formed at the other electrode at 1 atm pressure and 298 K is _______ litres. (rounded off to one decimal place)
[Given: The gas constant 𝑅 = 0.082 L atm mol⁻¹ K⁻¹ , the molar mass of Q is 40 g mol⁻¹ and Cl₂ is assumed to be an ideal gas]

Answer 1

Correct Answer: 12.1 - 12.3

We are given the following data:

• Mass of metal Q formed = 40 g
• Molar mass of Q = 40 g/mol (assumed)
• The gas constant R = 0.082 L atm mol⁻¹ K⁻¹
• Temperature = 298 K
• Pressure = 1 atm

First, we calculate the number of moles of Q formed:

Moles of Q = \( \frac{\text{Mass of Q}}{\text{Molar mass of Q}} \)

Moles of Q = \( \frac{40 \, \text{g}}{40 \, \text{g/mol}} = 1 \, \text{mol} \)

Since one mole of Q produces one mole of Cl₂, we can now calculate the volume of Cl₂ using the ideal gas law:

PV = nRT

Substituting the known values:

\( (1 \, \text{atm})(V) = (1 \, \text{mol})(0.082 \, \text{L atm mol}^{-1} \text{K}^{-1})(298 \, \text{K}) \)

V = \( \frac{(1)(0.082)(298)}{1} \)

V = 12.1 L

Thus, the volume of Cl₂ formed is 12.1 litres.