How many grams of MgCO3 contain 24.00 g of oxygen? (The molar mass of MgCO3 is 84.30 g mol–1)
- 42.15 g
- 84.30 g
- 126.00 g
- 154.00 g
Answer
Mass of oxygen atom = 16 g
Mass of oxygen in 84.30 g of MgCO3 = 3 x 16 = 48 g
So, 24 g of oxygen will be in 42.15 g of MgCO3.
The correct option is A.