Question

10ml of concentrated H₂SO₄ (18M) is diluted to one litre. The approximate strength of the dilute acid is

(1)18 M (2)180 M (3)0.18 M (4)1.8M

Answer 1

Answer : 0.18 M

Initially 10ml of concentrated H₂SO₄ (18M) is present

So total mole of H₂SO₄ present initially = Molarity * Volume in litre

Molarity = 18M and Volume = 10mL = 0.01 L

Number of mole of H₂SO₄ = 18*0.01 = 0.18 Mole

Since H₂SO₄ is the strong acid and it has degree of disociation around 100% so all mole of H₂SO₄ will disociate fully into ions and so we can say strength and molarity will be same in strong acid like H₂SO₄ acid.

Now volume of solution changed to 1L

So strength of diluted acid will equal to molarity

Strength of diluted acid = 0.18/1 = 0.18 M