Question

Which of the following contains the greatest number of atoms?

• A. $1.0g$ of butane $\left(C_4{H}_{10}\right)$
• B. $1.0g$ of nitrogen $\left(N_2\right)$
• C. $1.0g$ of silver $(Ag)$
• D. $1.0g$ of water $\left(H_{2}O\right)$

Answer 1

Answer: (A)

Number of atoms = Number of molecules $\times$ number of atoms in one molecule

Number of atoms in $1.0g$ butane $\left(C_4{H}_{10}\right)$

$=\frac{1}{58}\times 6.023\times 10^{23}\times 14=1.45\times 10^{23}$

(1 molecule contains 14 atoms)

Number of atoms in $1.0g{N}_2$

$=\frac{1}{28}\times 6.023\times 10^{23}\times 2=4.3\times 10^{22}$

Number of atoms in $1.0g$ silver $(Ag)$

$=\frac{1}{108}\times 6.023\times 10^{23}=5.5\times 10^{21}$

Number of atoms in $1.0g$ water $\left(H_{2}O\right)$

$=\frac{1}{18}\times 6.023\times 10^{23}\times 3\approx 10^{23}$

Thus, butane has maximum number of atoms.