Chapter 3.4, Problem 19PP

Interpretation Introduction

Interpretation:

The mass percent of the hydrogen in the compound needs to be determined.

Concept introduction:

For any compound, the mass percent of any element present in it can be calculated as follows:

$\%m=\frac{m_{element}}{m_{compound}}\times 100\%$

Answer to Problem 19PP

15.89%

Explanation of Solution

The mass of the unknown compound is 78 g and the mass of hydrogen present in it is 12.4 g.

The mass percent of hydrogen in the compound can be calculated as follows:

$\%m_H=\frac{m_H}{m_{compound}}\times 100\%$

Putting the values,

$\begin{array}{l}\%m_H=\frac{12.4\text{ g}}{78\text{ g}}\times 100\%\\ =15.89\%\end{array}$

Conclusion

Thus, the mass percent of H is 15.89%.