22.2k views
4 votes
Calculate the molarity of an aqueous solution that is 22. 3% by mass calcium chloride. You might need to know that the density is 1. 20 g/ml.

1 Answer

6 votes

Answer:

Step-by-step explanation:

To calculate the molarity of the solution, we first need to determine the mass of calcium chloride (CaCl2) in 100 g of the solution.

If the solution is 22.3% calcium chloride by mass, this means that there are 22.3 g of CaCl2 in 100 g of the solution.

We can use the density of the solution to convert 100 g of the solution to its volume:

volume of 100 g of the solution = mass of the solution / density of the solution

volume of 100 g of the solution = 100 g / 1.20 g/mL = 83.3 mL

Now, we can calculate the molarity of the solution using the following formula:

molarity = moles of solute / volume of solution (in L)

The molar mass of CaCl2 is 40.08 + 2(35.45) = 110.98 g/mol. Therefore, the number of moles of CaCl2 in 22.3 g of the solution is:

moles of CaCl2 = 22.3 g / 110.98 g/mol = 0.2008 mol

The volume of the solution containing 22.3 g of CaCl2 is:

volume of solution = 83.3 mL / 1000 mL/L = 0.0833 L

Substituting these values into the formula for molarity, we get:

molarity = 0.2008 mol / 0.0833 L = 2.41 M

Therefore, the molarity of the aqueous solution that is 22.3% by mass calcium chloride is 2.41 M.

User Borrel
by
8.3k points