Question

6. What is the percent composition of chlorine in calcium chloride, CaCl₂?a. 32%b. 36%c. 50%d. 64%

Answer 1

The first step we have to follow is to find the molecular mass of CaCl2.

$\begin{gathered} Ca=40\times1=40 \\ Cl_2=35.45\times2=70.9 \\ CaCl_2=40+70.9=110.9 \end{gathered}$

Finally divide the mass of Cl2 by the mass of CaCl2 and multiply this product times 100:

$\frac{70.9}{110.9}\cdot100=63.93$

It means that the correct answer is 64%.