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

The Correct Option is 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
$=22 \times 0.074788 \times 6.023 \times 10^{23}$
$=9.9 \times 10^{23}$

Answer 2

We must understand that molar mass is a mass attribute of a material, not an atomic characteristic. The molar mass is a common characteristic of many instances of the compound, which regularly fluctuates in mass due to the presence of isotopes. Typically, the molar mass is derived from standard nuclear loads and is thus an earthbound normal and component of the overall riches of constituent iota isotope on Earth. The molar mass is appropriate for converting between a substance's mass and its measure for mass quantities.
The molecular weight is sometimes used as an equivalent phrase for molar mass, particularly for subatomic mixes; nonetheless, the most authoritative sources characterize it in an unexpected way. The equation weight is a molar mass equivalent term that is occasionally used for non-atomic mixes such as ionic salts.
Finally, each atom's atomic mass must be specified below.
The total number of atoms,
Carbon = 12
Hydrogen = 1
Oxygen = 16
Then, Sucrose (C₁₂H₂₂O₁₁),
Carbon = 12×12=144
Hydrogen = 1×22=22
Oxygen = 16×11=176
Therefore, the total molecular mass of sucrose is : 144+22+176=342 g/mol