Question

no. of hydrogen present in 25.6g of sucrose which has molar mass 342.3??

Answer 1

The number of hydrogen=342.3÷25.6=12.5 number of hydrogen.

Answer 2

Answer : The number of hydrogen atoms present in 25.6 g of sucrose is, $9.878\times 10^{23}$ atoms.

Solution : Given,

Mass of sucrose = 25.6 g

Molar mass of sucrose, $C_{12}H_{22}O_{11}$ = 342.3 g/mole

First we have to calculate the moles of $C_{12}H_{22}O_{11}$.

$\text{Moles of }C_{12}H_{22}O_{11}=\frac{\text{Mass of }C_{12}H_{22}O_{11}}{\text{Molar mass of }C_{12}H_{22}O_{11}}=\frac{25.6g}{342.3g/mole}=0.0747moles$

As, 1 mole of $C_{12}H_{22}O_{11}$ contains $6.022\times 10^{23}$ atoms

So, 0.0747 moles of $C_{12}H_{22}O_{11}$ contains $0.0747\times 6.022\times 10^{23}=0.449\times 10^[23}$ atoms

And the number of mole of hydrogen present in one molecule of sucrose is equal to 22 moles.

The required number of hydrogen atoms = $22\times 0.449\times 10^{23}=9.878\times 10^{23}$

Therefore, the required number of hydrogen atoms is, $9.878\times 10^{23}$ atoms.