Calculate the mass of the salt formed by the interaction of magnesium oxide weighing 8 g and 20%

Calculate the mass of the salt formed by the interaction of magnesium oxide weighing 8 g and 20% nitric acid solution weighing 157.5.

Given:
m (MgO) = 8 g
ω (HNO3) = 20%
m solution (HNO3) = 157.5 g

Find:
m (salt) -?

Solution:
1) MgO + 2HNO3 => Mg (NO3) 2 + H2O;
2) n (MgO) = m / M = 8/40 = 0.2 mol;
3) m (HNO3) = ω * m solution / 100% = 20% * 157.5 / 100% = 31.5 g;
4) n (HNO3) = m / M = 31.5 / 63 = 0.5 mol;
5) n (Mg (NO3) 2) = n (MgO) = 0.2 mol;
6) m (Mg (NO3) 2) = n * M = 0.2 * 148 = 29.6 g.

Answer: The mass of Mg (NO3) 2 is 29.6 g.