Question

The number of hydrogen atoms present in $25.6\, g$ of sucrose $\left( C _{12} H _{22} O _{11}\right)$ which has a molar mass of $342.3\, g$ is

• A. $22\times10^{23}$
• B. $9.91\times10^{23}$
• C. $11\times10^{23}$
• D. $44\times10^{23}H $atoms

Answer 1

Answer: (B)

Mole of sucrose $=\frac{\text { mass of sucrose (in gram) }}{\text { molecular weight of sucrose }} $
$=\frac{25.6}{342.3}=0.0747882$
Formula of sucrose $= C _{12} H _{22} O _{11}$
Number of $H $ atoms in one mole of sucrose $=22$
Number of $H$ atoms in $25.6 \,g$ of sucrose
$=22 \times 0.074788 \times 6.023 \times 10^{23}$
$=9.9 \times 10^{23}$