Question

How many grams of CaCl2 should be dissolved in 445.2 mL of water to make a 0.19 M solution of CaCl2?

Answer 1

9.3
Explanation is sorry I forgot the other numbers

Answer 2

In order to solve this, you will need to know how many moles of CaCl2 you will need, and to do so, you must look at the concentration of the solution.

You are told that the concentration of the solution is 0.19M, meaning that there is 0.19 moles of CaCl2 for every 1 liter of solution. However, you don't have 1 liter of solution, you have 445.2 mL. You must convert this to liters by dividing by 1000.

445.2 mL *  (1 L / 1000 mL) = 0.4452 L

Now, you can solve for how many moles the solution must have. Since M = mol / L and you are given M and L, you can set up an equality as follows:

0.19M = mol / 0.4452 L

Now, in order to find the number of moles, you multiply both sides by 0.4452L

0.19M * 0.4452 L = moles = 0.084588mol  

Now, you must calculate the molar mass of CaCl2 by using the periodic table

MM Ca = 40.078 g/mol

MM Cl = 35.452 g/mol

40.078 + (35.452 * 2) = 110.982 g/mol

Now you multiply the number of moles in the solution you calculated by the molar mass.

0.084588mol * 110.982 g/mol = 9.387 g CaCl2