Question

The ph of the solution formed when 0.02 mol of hcl is added to enough water to make the final volume 2.0l is

Answer 1

Number of moles of H⁺ = 2×10⁻²
Total volume of solution = 2.0L
Concentration of H⁺ = [H⁺] = 10⁻² M
pH = -㏒[H⁺] = -㏒(10⁻²) = 2
pH = 2

Answer 2

Hello Dear.

Given ⇒

Volume of the Solutions = 2 liter.

When HCl is added to the water, H⁺ ions are formed due to the Ionization of the HCl in water.

No. of moles of the H⁺ formed = 0.02 moles.

∵ Concentration of the Solutions = No. of moles/Volume of the Solution.
   = 0.02/2
   = 0.01
   = 10⁻²

Now,
∵ pH = - log [H]⁺
∴ pH = - log[10⁻²]
        = 2 log 10

∵ log 10 = 1

∴ pH = 2 ×1
         = 2


Hence, the pH of the Solution is 2.


Hope it helps.