Answer :
So,
The molar mass of CaBr2 is 199.89g/mol.
In this amount, there's 40g of Ca.
Our sample contains 15g of Ca, so, we could state the following equality:
Now,
[tex]x=\frac{15\text{gCa}\cdot199.89\text{gCaBr}2}{40\text{gCa}}=74.8\text{gCaBr}2[/tex]Therefore, in a sample that contais 15.0g of Calcium, there's 74.8 grams of CaBr2.
