Balanced chemical equation:
Ba(OH)2 + 2HCl → BaCl2 + 2H2O
Moles of Ba(OH)2 used:
$$ = M \times V = 0.1 \times \frac{25}{1000} = 2.5 \times 10^{-3}\ \text{mol} $$
From stoichiometry:
1 mol Ba(OH)2 reacts with 2 mol HCl
Moles of HCl used:
$$ = 2 \times 2.5 \times 10^{-3} = 5.0 \times 10^{-3}\ \text{mol} $$
Mass of HCl:
$$ = n \times M = 5.0 \times 10^{-3} \times 36.5 = 0.1825\ \text{g} $$
Convert into mg:
$$ 0.1825\ \text{g} = 182.5\ \text{mg} $$
Given format:
$$ x \times 10^{-1} = 182.5 $$
$$ x = 1825 $$
Hence, the required value of x is 1825.
Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.