Question

20
what is the percent by mass of oxygen in compound below? (1 point)
$c_{6}h_{12}o_{6}$
8.88%
40.0%
83.2 %
53.3%

Explanation:

Step1: Calculate molar mass of \(C_6H_{12}O_6\)

Molar mass of \(C\) is \(12.01\ g/mol\), \(H\) is \(1.008\ g/mol\), \(O\) is \(16.00\ g/mol\).
Molar mass of \(C_6H_{12}O_6=6\times12.01 + 12\times1.008+6\times16.00\)
\(=72.06+12.096 + 96\)
\(=180.156\ g/mol\)

Step2: Calculate mass of oxygen in \(C_6H_{12}O_6\)

Mass of oxygen \(=6\times16.00 = 96\ g/mol\)

Step3: Calculate mass percent of oxygen

Mass percent of \(O=\frac{\text{Mass of }O}{\text{Molar mass of }C_6H_{12}O_6}\times100\%\)
\(=\frac{96}{180.156}\times100\%\approx53.3\%\)

Answer:

\(53.3\%\) (the fourth option)