Question

To make a 2 M solution of calcium chloride (CaCl2), you would place how many grams of CaCl2 into a container and then add how much pure water? [mass of a Ca atom = 40; mass of a Cl atom = 35; mass of an O atom = 16; mass of an H atom = 1] A) 220 grams of CaCl2 then add water to make a total volume of 1 liter B) 128 grams of CaCl2 then add water to make a total volume of 1 liter C) 150 grams of CaCl2 then add water to make a total volume of 1 liter. D) 110 grams of CaCl2 then add water to make a total volume of 1 liter E) none of the above is correct

Answer 1

Answer:

For a volume of 1 liter, we have a total mass of 220 grams of CaCl2 ( Option A)

Explanation:

Step 1: Given data

The concentration of the solution we want to make is 2M

2M = 2 moles/ L So the volume = 1L

The molar mass of CaCl2 is = 40 + 2*35 = 110g/mole

Step 2: Calculate number of moles

If we consider the volume = 1 L then for a concentration of 2M, this means the number of moles is 2

Step 3:  Calculate mass

The molar mass of CaCl2 = 110 g/mole

This means 110 grams per 1 mole

for 2 moles the mass is 220 grams

This means that for a volume of 1 liter, we have a total mass of 220 grams of CaCl2