150 grams of a 12.6% solution of HNO3 + CuO. Find the mass of salt.

Let’s write the reaction equation:

2HNO3 + CuO → Cu (NO3) 2 + H2O

Find the mass of salt in the solution. To do this, we will use the formula:

m.w. (HNO3) = (w.w. (HNO3) * m.w. (HNO3)) / 100% = (12.6% * 150 g) / 100% = 18.9 g.

Let’s find the amount of nitric acid substance:

n (HNO3) = m (HNO3) / M (HNO3) = 18.9 g / 63 g / mol = 0.3 mol.

Let’s find the amount of copper (II) nitrate substance:

n (Cu (NO3) 2) = 0.5 * n (HNO3) = 0.5 * 0.3 mol = 0.15 mol.

We calculate the mass of copper (II) nitrate:

m (Cu (NO3) 2) = n (Cu (NO3) 2) * M (Cu (NO3) 2) = 0.15 mol * 188 g / mol = 28.2 g.

Answer: 28.2 g.