Calculate the mass of magnesium oxide obtained by burning magnesium with a mass of 2.4 kg

2 Mg + O2 = 2 MgO;
m = M * ν;
ν = m / M;
M (Mg) = 24 g / mol;
m (Mg) = 2.4 kg = 2400 g.
Let’s find the amount of Mg substance:
ν (Mg) = 2400 g / 24 g / mol = 100 mol;
M (MgO) = 24 + 16 = 40 g / mol.
The molar ratios of Mg and MgO are equal to each other.
Find the mass of Mg oxide:
m (MgO) = 40 g / mol * 100 mol = 4000 g = 4 kg.
Answer: m (MgO) = 4 kg.