Chapter 3, Problem 78A

Interpretation Introduction

Interpretation:

The percent mass of chlorine in an unknown compound needs to be determined.

Concept introduction:

There are many ways of finding concentration of an element in a compound or a component in a mixture. Mass percent is one of those ways in which the concentration can be calculated.

The mass percent of an element in any compound is found as:

$\mathrm{mass}\%oftheelement=\frac{massoftheelement}{totalmassofcompound}\times 100$

Answer to Problem 78A

Mass percent of chlorine in unknown salt is $64\%$.

Explanation of Solution

Mass percent of chlorine can be calculated as:

$\mathrm{mass}\%ofCl=\frac{massofCl}{totalmassofcomp.}\times 100$

Unknown salt is $100\mathrm{gm}$.

Chlorine present is $64\mathrm{gm}$.

If the metal is taken as X in the salt.

$X+Cl\to XCl$

$\mathrm{mass}\%ofCl=\frac{64}{100}\times 100=64\%$

Conclusion

Mass percent of chlorine in unknown salt comes out to be $64\%$ that is calculated by dividing the mass of that particular element with the total mass of compound multiplied by $100$.