Calculate what mass of magnesium nitrate will be obtained by reacting magnesium oxide

Calculate what mass of magnesium nitrate will be obtained by reacting magnesium oxide with a solution containing 18 g of nitric acid.

To solve the problem, it is necessary to compose the reaction equation:
MgO + 2HNO3 = Mg (NO3) 2 + H2O – ion exchange reaction, sodium nitrate salt is obtained;
Let’s make calculations using the formulas:
M (HNO3) = 1 + 14 + 16 * 3 = 63 g / mol;
M Mg (NO3) 2 = 24.3 + (14 + 48) * 2 = 148.3 g / mol;
Determine the amount of mol of nitric acid, if the mass is known:
Y (HNO3) = m / M = 18/63 = 0.285 mol;
Let’s make the proportion:
0.285 mol (HNO3) – X mol Mg (NO3) 2;
-2 mol -1 mol hence, X mol Mg (NO3) 2 = 0.285 * 1/2 = 0.14 mol;
We calculate the mass of magnesium nitrate by the formula:
m Mg (NO3) 2 = Y * M = 0.14 * 148.3 = 20.76 g.
Answer: during the reaction, magnesium nitrate with a mass of 20.76 g is formed.