1. Write the Balanced Chemical Equation

The general reaction for roasting a metal sulfide is:

2 MS + 3 O₂ → 2 MO + 2 SO₂

Where:

* M is the metal

* S is sulfur

* O is oxygen

2. Calculate the Mass of Sulfur Lost

* Mass of sulfide = 1.326 g

* Mass of oxide = 0.824 g

* Mass of sulfur lost = Mass of sulfide - Mass of oxide = 1.326 g - 0.824 g = 0.502 g

3. Calculate the Moles of Sulfur Lost

* Molar mass of sulfur (S) = 32.06 g/mol

* Moles of sulfur = Mass of sulfur / Molar mass of sulfur = 0.502 g / 32.06 g/mol = 0.0156 mol

4. Calculate the Moles of Metal Oxide Formed

* From the balanced equation, 2 moles of MS produce 2 moles of MO.

* Therefore, the moles of metal oxide formed are equal to the moles of sulfur lost: 0.0156 mol.

5. Calculate the Mass of Metal Oxide Formed

* Moles of metal oxide = 0.0156 mol

* Mass of metal oxide = 0.824 g (given)

* Molar mass of metal oxide = Mass of metal oxide / Moles of metal oxide = 0.824 g / 0.0156 mol = 52.82 g/mol

6. Calculate the Molar Mass of the Metal

* Molar mass of metal oxide (MO) = Molar mass of metal (M) + Molar mass of oxygen (O)

* Molar mass of oxygen (O) = 16.00 g/mol

* Molar mass of metal (M) = Molar mass of metal oxide - Molar mass of oxygen = 52.82 g/mol - 16.00 g/mol = 36.82 g/mol

Therefore, the molar mass of the metal is approximately 36.82 g/mol.

Note: The oxidation number of the metal is given as +2, which is consistent with the general formula for metal sulfides (MS) and oxides (MO). This information is not needed for the actual calculation but helps verify the assumed chemical equation.