How many moles of cacl2 would be used in making 0.5L of a 2M solution?

To find the number of moles of CaCl2 needed to make a 2M solution in a 0.5L volume, you need to use the formula:

Moles = Molarity x Volume (in liters)

Given:
Molarity (M) = 2M
Volume (V) = 0.5L

Substitute the values into the formula:

Moles = 2M x 0.5L

Moles = 1 mol

So, 1 mole of CaCl2 would be used to make a 0.5L solution with a concentration of 2M.