A solution is prepared by dissolving 27.7 g of CaCl2 in 375 g of water. The density of the resulting solution is 1.05 g/mL. The concentration of CaCl2 is % by mass. A solution is prepared by dissolving 27.7 g of CaCl2 in 375 g of water. The density of the resulting solution is 1.05 g/mL. The concentration of CaCl2 is % by mass. 6.24 6.88 7.22 0.0722 0.0688

6.88%

Explanation:

Step 1: Given data

Step 2: Calculate the mass of the solution

The mass of the solution is equal to the sum of the masses of the solute and the solvent.

mSolution = mSolute + mSolvent

mSolution = 27.7 g + 375 g = 402.7 g

Step 3: Calculate the percentage by mass of CaCl₂

We will use the following expression.

%m/m = mass CaCl₂/mass Solution × 100%

%m/m = 27.7 g/402.7 g × 100% = 6.88%

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%