Question

Which of the following contains the greatest number of atoms?

• A. $1.0 \,g$ of butane $\left( C _{4} H _{10}\right)$
• B. $1.0 \,g$ of nitrogen $\left( N _{2}\right)$
• C. $1.0 \,g$ of silver $(Ag)$
• D. $1.0\, g$ 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 $1.0\, g$ 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 $1.0 \,g\, N _{2}$

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

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

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

Number of atoms in $1.0 \,g$ 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.