Mass of oxygen in Glucose is 5333 55 6633 7788 Glucose

SOLUTION

Glucose is $C_6{H}_{1}2O_6$
Molecular mass = (6 $\times$ 12) + (12 $\times$ 1) + (6 $\times$ 16)
= 180 u
Of the 180, (16 $\times$ 6)u is contributed by oxygen.

$\therefore$ mass % of oxygen = $\frac{96}{180}$ $\times$  100 = 53.33 %