Amethod that could be used to separate salt and water

evaporation of the liquid (water) via boiling

Explanation:

Since salt dissolves in water, you probably are starting with a saline solution. The only way of separating them will be to get rid of water in its liquid phase evaporating it, and collecting the salt whose evaporation point is much higher than that of the water.

So raise the temperature of the solution bringing it to boiling, thus getting rid of water in form of vapor. Collect the salt that now separated from the water collects at the bottom of the container.

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%