Question

How many grams of CaCl2 are needed to make 277.8g of a solution that is 31.5% (m/m) in water? Note that mass is not technically the same thing as weight, but % (m/m) has the same meaning as % (w/w).

Answer 1

Answer: The mass of calcium chloride present in given amount of solution is 87.5 g

Explanation:

We are given:

Mass of solution = 277.8 grams

Also, 31.5 % (m/m) of calcium chloride in water. This means that 31.5 g of calcium chloride is present in 100 g of solution.

To calculate the mass of calcium chloride in the given amount of solution, we use unitary method:

in 100 g of solution, the mass of calcium chloride present is 31.5 g

So, 277.8 g of solution, the mass of calcium chloride present is $\frac{31.5}{100}\times 277.8=87.5g$

Hence, the mass of calcium chloride present in given amount of solution is 87.5 g