Question

Calculate ph of0.02m sulphuric acid solution

Answer 1

Answer:

2 - log(4) ≅ 1.4

Explanation:

pH means power of hydrogen , it is calculated by using concentration of H⁺ ions

pH = -log₁₀[H⁺]  ; [H⁺] = concentration of H⁺ ions

Sulphuric acid (H₂SO₄) is a dibasic acid as it contains two ionisable H atoms

Concentration of H⁺ here will two times the concentration of H₂SO₄

[H⁺] = 2×0.02 = 0.04

pH = -log[0.04] = -log[4×10`²]

                         =  - {log[4] + log[10`²] }                 [ log(mn) = log(m) + log(n) ]

                         =  -log[4] - log[10`²]                     [ log(aᵇ) = b×log(a)  ]

                         =   -0.6 - (-2)log[10]

                         =   -0.6 + 2log[10]                         [log₁₀10 = 1]

                         =    -0.6 + 2×1 = -0.6 + 2 = 1.4