Question

Round the answer to the nearest whole number the present composition of cl in CaCl2 is %

Answer 1

So,

First of all, let's find the molar mass of CaCl2:

$\begin{gathered} Ca\colon\frac{40g}{\text{mol}} \\ \\ Cl\cdot\frac{35.45g}{\text{mol}}\cdot2=\frac{70.9g}{\text{mol}} \\ \\ \text{CaCl}_2=40+70.9=\frac{110.9g}{mol} \end{gathered}$

We want to find the percent composition of Cl in the compound. So:

We have 70.9 grams of Cl2 in a total of 110g. What we're going to do is to divide these amounts and then multiply by 100:

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

If we round to the nearest whole number, that's 64%.

So the answer is 64%.