Question

2.0 g of oxygen contains number of atoms equal to that in

• A. 0.5 g of hydrogen
• B. 4 g of sulphur
• C. 7 g of nitrogen
• D. 2.3 g of sodium

Answer 1

Answer: (B)

Number of atoms in 1 g of an element
$=\frac{6.023\times 10^{23}}{at.mass}$
$\therefore$ Number of atoms in 2 g of oxygen
$=\frac{6.023\times 10^{23}}{16}\times 2=\frac{6.023\times 10^{23}}{8}$
Now, number of atoms in 4 g of sulphur
$=\frac{6.023\times 10^{23}}{32}\times 4=\frac{6.023\times 10^{23}}{8}$