A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 45.0 g of calcium fluoride

23.1 g of Ca

Solution:

It is a simple proportional problem in which we will find either the increased or decreased value of calcium with proportional to Calcium fluoride.

Therefore as given,

15.0 g of pure CaF₂ contains = 7.70 g of Ca

So,

45.0 g of pure CaF₂ will contain = X g of Ca

Solving for X,

X = (45.0 g * 7.70 g) : 15.0 g

X = 23.1 g of Ca

Hence, as the amount of CaF₂ has increased from 15.0 g to 45.0 g therefore, the amount of Ca it contained also increased from 7.70 g to 23.1 g.