Correct Answer: (i) 12.044 × 10^{20} molecules

Explanation: Moles of H_{2}SO_{4}= Molarity of H_{2}SO_{4}×Volume of solution (L)

Hence, the number of molecules of H_{2}SO_{4} present in 100 mL of 0.02M H_{2}SO_{4} solution is12.044 × 10^{20} molecules.