Question

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

• A. $22\times 10^{23}$
• B. $9.91\times 10^{23}$
• C. $11\times 10^{23}$
• D. $44\times 10^{23}H$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 $25.6g$ of sucrose
$=22\times 0.074788\times 6.023\times 10^{23}$
$=9.9\times 10^{23}$