Magnesium oxide was treated with 0.1 mol of the substance with a solution containing 15 g

Magnesium oxide was treated with 0.1 mol of the substance with a solution containing 15 g of nitric acid. Calculate the mass of the resulting salt.

Given:
n (MgO) = 0.1 mol
m (HNO3) = 15 g
To find:
m (Mg (NO3) 2) =?
Decision:
1) We draw up the equation of the chemical reaction, let the mass of the salt be x g.
MgO + 2HNO3 = Mg (NO3) 2 + H2O
2) Find the amount of nitric acid substance.
n = m / M
M (HNO3) = 1 + 14 + 48 = 63 g / mol
n (HNO3) = 15 g: 63 g / mol = 0.23 mol.
It turns out that there is a lack of magnesium oxide and we will decide on it.
3) Find the mass of magnesium oxide.
m = n x M
M (MgO) = 24 + 16 = 40 g / mol
n (MgO) = 0.1 mol x 40 g / mol = 4 g.
4) M (Mg (NO3) 2) = 24 + 28 + 96 = 148 g / mol
4 g: 40 g / mol = x g: 148 g / mol
x = (4 x 148): 40 = 14.8 g.
Answer: m (Mg (NO3) 2) = 14.8 g.