Question

What is the number of oxygen atoms present in 5 moles of sulphuric acid $\left(H_{2}S{O}_4\right)$?

• A. $120.44\times {10}^{23}$
• B. $90.33\times {10}^{23}$
• C. $60.22\times {10}^{23}$
• D. $75.55\times {10}^{23}$

Answer 1

Answer: (A)

Step 1:

The molecular formula of sulphuric acid is ${\text{H}}_2{\text{SO}}_4$ .

One molecule of ${\text{H}}_2{\text{SO}}_4$ has 4 atoms of oxygen.

So, one mole of sulphuric acid will have 4 moles of oxygen.

Therefore, 5 moles of sulphuric acid will have 4$\times$ 5 = 20 moles of oxygen atoms.

Step 2:

One mole of any substance will have $6.022\times {10}^{23}$ particles of that substance.

Hence, the total number of oxygen atoms in 5 moles of ${\text{H}}_2{\text{SO}}_4$
$=20\times 6.022\times {10}^{23}$
$=120.44\times {10}^{23}$ atoms.

Hence, option (A) is correct.