Question

You need to dissolve CaCl2 in water to make a mixture that is 40.0% calcium chloride by mass. If the total mass of the mixture is 370.9g, what masses of CaCl2 and water should be used?.

Answer 1

Answer: Mass of
`CaCl_2` and water to be used is 148.4 g and 222.5 g respectively.

Explanation:

To calculate the mass percent of element in a given compound, we use the formula:

`\text{Mass percent of calcium chloride}=\frac{\text{Mass of calcium chloride}}{\text{Mass of mixture}}* 100`

Given : mass percent of calcium chloride = 40.0 %

Mass of mixture (calcium chloride + water) = 370.9 g

Putting in the values we get:

`40=\frac{\text{Mass of calcium chloride}}{370.9g}* 100`

`{\text{Mass of calcium chloride}}=148.4g`

Mass of calcium chloride + mass of water = 370.9

Mass of water = 370.9 g- 148.4 g = 222.5 g

Thus mass of
`CaCl_2` and water to be used is 148.4 g and 222.5 g respectively.

Answer 2

For finding the masses of calcium chloride and water used first we have to find for calcium chloride it will be
40%/100%*370.09
as the 100% is the total percent and 370.09 is toatal mass of mixture so it will b
40%/100%*370.09=148.4g

now for water the remaining percent is 60 so it will be
60/100*370.09=222.5

148.4g of CaCl2 and 222.5 of water is used
hope it helps