Question

the volume of water to be added to 50ml of 0.5N h2so4 to get decinormal concentration of h2so4​

Answer 1

Answer: 200 ml

Explanation:

The volume of H₂SO₄, V₁ = 50 ml

The normality of H₂SO₄, N₁ = 0.5N

Normality of the concentration of water mixed H₂SO₄, N₂ = [1/10] N

Let the volume of the water to be added be denoted as “V2” ml .

Now,  

The milli-equivalents of H₂SO₄ = N₁ * V₁ = 50 * 0.5 = 25 meq. …. (i)

and,

The milli-equivalents of decinormal concentration of H₂SO₄ = N₂ * [V₁+V₂] = [(1/10)*(50+V₂)] meq ….. (ii)

Since after dilution the no. of milli-equivalent of the solute remains constant, therefore, we can equate eq.(i) & (ii),

[(1/10)*(50+V₂)] = 25

⇒ 50 + V₂ = 25 * 10

⇒ V₂ = 250 – 50  

⇒ V₂ = 200ml

Thus, 200 ml of water is required to be added.