3.36 liters of carbon dioxide reacted with 8 grams of magnesium oxide. What is the mass of magnesium carbonate formed?

Given:
V (CO2) = 3.36 l
m (MgO) = 8 g

To find:
m (MgCO3) -?

Decision:
1) MgO + CO2 => MgCO3;
2) M (MgO) = Mr (MgO) = Ar (Mg) * N (Mg) + Ar (O) * N (O) = 24 * 1 + 16 * 1 = 40 g / mol;
M (MgCO3) = Mr (MgCO3) = Ar (Mg) * N (Mg) + Ar (C) * N (C) + Ar (O) * N (O) = 24 * 1 + 12 * 1 + 16 * 3 = 84 g / mol;
3) n (CO2) = V (CO2) / Vm = 3.36 / 22.4 = 0.15 mol;
4) n (MgO) = m (MgO) / M (MgO) = 8/40 = 0.2 mol;
5) n (MgCO3) = n (CO2) = 0.15 mol;
6) m (MgCO3) = n (MgCO3) * M (MgCO3) = 0.15 * 84 = 12.6 g.

Answer: The mass of MgCO3 is 12.6 g.