Question

Which has maximum no. of molecules among the following and why?

• A. $44\mathrm{g}$ of ${\mathrm{CO}}_2$
• B. $48\mathrm{g}$of ${\mathrm{O}}_2$
• C. $8\mathrm{g}\mathrm{of}{\mathrm{H}}_2$
• D. $64\mathrm{g}\mathrm{of}{\mathrm{SO}}_2$

Answer 1

The correct option is C

$8\mathrm{g}\mathrm{of}{\mathrm{H}}_2$

Explanation of correct answer

(C) $\mathbf{8}\mathbf{}\mathbf{g}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{H}}_{\mathbf{2}}$

Molecules

• One or more atoms make form a molecule.
• The amount of a substance that contains the same number of elementary particles(ions, molecules, or atoms) as the number of atoms present in $12\mathrm{g}$ of carbon $\mathrm{C}12$ is called the molecule.
• There are $6.022\mathrm{x}{10}^{23}$ hydrogen atoms in one molecule of hydrogen.

$\mathbf{8}\mathbf{}\mathbf{g}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{H}}_{\mathbf{2}}$

• The number of moles of solute per liter of solution is known as molarity.
• The equation for determining the number of molecule as follows:

$\mathrm{Mole}=\frac{\mathrm{Mass}}{\mathrm{Molecular}\mathrm{mass}}\times 6.022\mathrm{x}{10}^{23}$

• The number of molecules in $8\mathrm{g}\mathrm{of}{\mathrm{H}}_2$:

${\mathrm{H}}_2$ = $\frac{8}{2}\times 6.022\mathrm{x}{10}^{23}$ = $24.088\mathrm{x}{10}^{23}\mathrm{molecules}$.

Explanation of incorrect answer

(A) $44\mathrm{g}\mathrm{of}{\mathrm{CO}}_2$

• The number of molecules in $44\mathrm{g}\mathrm{of}{\mathrm{CO}}_2$:

${\mathrm{CO}}_2$ = $\frac{44}{44}\times 6.022\mathrm{x}{10}^{23}$ = $6.022\mathrm{x}{10}^{23}\mathrm{molecules}$

(B) $48\mathrm{g}\mathrm{of}{\mathrm{O}}_2$

• The number of moles in $48\mathrm{g}\mathrm{of}{\mathrm{O}}_2$:

${\mathrm{O}}_3$ = $\frac{48}{48}\times 6.022\mathrm{x}{10}^{23}$ = $6.022\mathrm{x}{10}^{23}\mathrm{molecules}$

(D) $64\mathrm{g}\mathrm{of}{\mathrm{SO}}_2$

• The number of molecules in $64\mathrm{g}\mathrm{of}{\mathrm{SO}}_2$:

${\mathrm{SO}}_2$ = $\frac{64}{64}\times 6.022\mathrm{x}{10}^{23}$ = $6.022\mathrm{x}{10}^{23}\mathrm{molecules}$.

Therefore, the correct option is (C) $8\mathrm{g}\mathrm{of}{\mathrm{H}}_2$