Question

Glucose is a physiological sugar. If the mass percentage of $C=x\%$, mass percent of $H=y\%$ and mass percent of $O=z\%$ in glucose $\left(C_6{H}_{12}{O}_6\right)$, then the value of $x,y$ and $z$ are, respectively:

• A. $40,6.67,53.33$
• B. $30,6.67,43.33$
• C. $40,7.67,63.33$
• D. none of the above

Answer 1

The correct option is A $40,6.67,53.33$

Molecular weight of glucose $=C_6{H}_{12}{O}_6=12\times 6+1\times 12+16\times 6$ $=180$ g
$180$ g of glucose contains $72$ g of $C$.
Percnetage of $C=\frac{72\times 100}{180}=40\%$

Percentage of $H=\frac{12\times 100}{180}=6.67\%$

Percentage of $O=\frac{96\times 100}{180}=53.33\%$