Question

$80g$ of oxygen contains as many atoms as in

• A. $80g$ of hydrogen
• B. $1g$ of hydrogen
• C. $10g$ of hydrogen
• D. $5g$ of hydrogen

Answer 1

Answer: (D)

Number of moles of oxygen $=\frac{80}{16}$

Number of atoms of oxygen $=\frac{80}{16}\times N_0\times 2$

$=5\times N_0\times 2$

Number of moles of $5g$ of hydrogen $=\frac{5}{1}$

Number of atoms in $5g$ of hydrogen $=5\times N_0\times 2$

Hence, the number of atoms in $80g$ of oxygen is equal to the number of atoms in $5g$ of hydrogen.