Question

We have a pure $H_{2}S{O}_4$ sample and it contains a total of 1120 hydrogen atoms. Find the number of $H_{2}S{O}_4$ molecules present in the sample.

• A. 560
• B. 2240
• C. 1120
• D. 1000

Answer 1

The correct option is A 560

1 mole of $H_{2}S{O}_4$ contains 2 moles of H atoms.
So, 2 moles of H-atoms are present in 1 mole of $H_{2}S{O}_4$.
Again, $6.022\times {10}^{23}$ H-atoms = 1 mole of H-atoms.
Therefore, 1120 H-atoms = $\frac{1120}{6.022\times {10}^{23}}$ moles of H-atoms.
Hence, the number of $H_{2}S{O}_4$ molecules present in the sample
$=\frac{1120}{6.022\times {10}^{23}}\times \frac{1}{2}\times 6.022\times {10}^{23}=560$