QJEEM20Chaf61: JEE Main 2020 Chemistry - Class 11 JEEM20Chaf61 Solution: The flocculation value of HCl for arsenic sulphide sol. is 30 m …

Arsenic sulphide sol is negatively charged, so for flocculation positive ion required. Here positive ion H⁺ present.

for 1 L, 30 mm moles of H⁺ is required

for 250 ml, $$\frac{30}{4}$$ mm moles H⁺ is required

$$\therefore$$ for 250 ml, $$\frac{30}{4\times 2}$$ mm moles H₂SO₄ is required.

$$\therefore$$ Weight of H₂SO₄ required = $$\frac{30}{4\times 2}\times {10}^{-3}\times 98$$

= 0.3675 g