The number of water molecules in 50 g of Glauber’s salt is equal to ..

1. Formula of Glauber’s salt Na2SO4 * 10H2O, from the formula it can be seen that one salt molecule includes 10 water molecules;

2. find the chemical amount of Glauber’s salt:

n (Na2SO4 * 10H2O) = m (Na2SO4 * 10H2O): M (Na2SO4 * 10H2O);

M (Na2SO4 * 10H2O) = 23 * 2 + 32 + 16 * 4 + 10 * 1 * 2 + 10 * 16 = 322 g / mol;

n (Na2SO4 * 10H2O) = 50: 322 = 0.1553 mol;

3. find the chemical amount of 10 water molecules:

n (10H2O) = 10 * n (Na2SO4 * 10H2O);

n (10H2O) = 0.1553 * 10 = 1.553 mol;

4.The number of H2O molecules is calculated by the formula using Avogadro’s constant:

N (H2O) = n (10H2O) * Na, where Na = 6.02 * 10 ^ 23 mol-1;

N (H2O) = 1.553 * 6.02 * 1023 = 9.35 * 10 ^ 23 molecules.

Answer: 9.35 * 10 ^ 23 molecules.