Question

What is the molality of CrCl3 in a solution prepared by dissolving 75.2 g chromium(III) chloride hexahydrate in 250.0 g of water.

1.) 7.60 m
2.) 1.90 m
3.) 1.13 m
4.) 0.282 m
5.) 5.64 m

Answer 1

The molality of the CrCl3 solution is 1.13 m

Step-by-step explanation:

To calculate the molality of a solution, we need to first determine the number of moles of solute and the mass of the solvent. In this case, the solute is chromium(III) chloride hexahydrate (CrCl3·6H2O) and the solvent is water. The molar mass of CrCl3·6H2O is 266.4 g/mol.

First, we calculate the number of moles of CrCl3·6H2O: 75.2 g / 266.4 g/mol = 0.282 mol.

Then, we calculate the mass of the solvent (water): 250.0 g.

Finally, we use the formula for molality:

Molality (m) = moles of solute / mass of solvent (in kg)

Plugging in the values, we get:

Molality (m) = 0.282 mol / 0.250 kg = 1.13 m.

Answer 2

The molality of CrCl3 in the solution is approximately 1.13 m, which is calculated by dividing the number of moles of CrCl3·6H2O by the mass of the water in kilograms.

Step-by-step explanation:

To calculate the molality of CrCl3 in a solution prepared by dissolving 75.2 g chromium(III) chloride hexahydrate (CrCl3·6H2O) in 250.0 g of water, follow these steps:

1. First, find the molar mass of chromium(III) chloride hexahydrate by adding the atomic masses of all atoms in the formula. The molar mass of CrCl3·6H2O is approximately 266.45 g/mol.
2. Next, convert the mass of the solute (CrCl3·6H2O) to moles by dividing by its molar mass:
   Moles of CrCl3·6H2O = 75.2 g / 266.45 g/mol ≈ 0.282 moles.
3. Then, convert the mass of the solvent (water) from grams to kilograms:
   250.0 g = 0.250 kg.
4. The molality (m) is calculated as the number of moles of solute per kilogram of solvent, so:
   Molality of CrCl3 = 0.282 moles / 0.250 kg ≈ 1.13 m.