Question

Number of atoms in the following samples of substances is largest in :

• A. $4.0g$ of hydrogen
• B. $71.0g$ of chlorine
• C. $127.0g$ of iodine
• D. $48.0g$ of magnesium

Answer 1

Answer: (A)

$4g$ of hydrogen = 4 mole of hydrogen
$=4\times 6.023\times 10^{23}$ atoms
$71.0$ gm of chlorine $\frac{71.0}{71.0}=1$ = moles of chlorine
$=6.023x10^{23}$ atoms
$127$ gm of iodine $=\frac{1}{2}$ mole of $I_2$
$=\frac{127}{254}=6.023\times 10^{23}\times \frac{1}{2}$ atoms
$48.,gm$ of magnesium
$=\frac{48.0}{24.0}=2\times 6.023\times 10^{23}$ atoms
$\therefore 4.0gm{H}_2$ has largest number of atoms.