Question

1g of a carbonate (M₂CO₃) on treatment with excess HCl produces 0.01 mol of CO₂ .The molar mass of M₂CO₃ is g mol^-1. (Nearest integer)

Answer 1

Correct Answer: 100

To find the molar mass of M₂CO₃, we follow these steps:

1. The reaction of the carbonate with HCl is:

M₂CO₃ + 2HCl → 2MCl + CO₂ + H₂O

2. From the problem, 0.01 mol of CO₂ is produced. The stoichiometry of the reaction indicates that 1 mol of M₂CO₃ gives 1 mol of CO₂. Thus, 0.01 mol of M₂CO₃ must have been used.

3. We know 1 g of M₂CO₃ was used to produce this amount of CO₂.

4. The molar mass (M) of M₂CO₃ is calculated using:

M (M₂CO₃) = mass/moles

M = 1 g / 0.01 mol = 100 g/mol

5. We verify that 100 g/mol is within the range 100,100. The calculated molar mass matches exactly with the provided range, ensuring correctness.

Therefore, the molar mass of M₂CO₃ is 100 g/mol.