Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020ChemistryIonic EquilibriumPractice

What is the OH − concentration of a 0 .04 M solution of CH 3 COONa? [K a of CH 3 COONa = 2 × 10 − 5 , log 2 = 0 .30, log 5 = 0 .69, 10 0 .7 ≅ 5]

Options

  1. A5 × 10 - 6
  2. B6 × 10 - 6
  3. C2 × 10 - 9
  4. D3 × 10 - 9

Correct answer

A. 5 × 10 - 6

Step-by-step solution

pK a = − log K a = − log (2 × 10 − 5 ) = 5 - l o g 2 = 5 - 0.3 = 4.7 pH = 1 2 pK w + pK a + log C p H = 1 2 [ 14 + 4.7 + log ⁡ 0.04 ] p H = 8.63 pOH   =   14 − 8 .63   ≅   5 .3 O H - = 5 × 10 - 6

Practice Ionic Equilibrium on Quantrex Academy →

More from Ionic Equilibrium

Given is a concentrated solution of a weak electrolyte A_xB_y of concentration 'c' and dissociation constant 'K'. The degree of dissociation is given by : 2026M₃ A₂ is a sparingly soluble salt of molar mass y g mol ⁻¹ and solubility x g L ⁻¹ . The ratio of the molar concentration of the anion ( A³⁻ ) to the solubility product of the salt 2026Arrange the following resultant mixtures in increasing order of their pH values A. 10 mL 0.2 M Ca(OH)₂ + 25 mL 0.1 M HCl B. 10 mL 0.01 M H₂ SO₄ + 10 mL 0.01 M Ca(OH)₂ C. 10 mL 0.1 202620 mL of a solution of acetic acid required 28.4 mL of 0.1 M NaOH for its neutralization. A solution (X) was prepared by mixing 20 mL of the above acetic acid and 14.2 mL of 0.1 M 2026The pH of a solution obtained by mixing 5 mL of 0.1 M NH₄OH solution with 250 mL of 0.1 M NH₄Cl solution is _____ 10⁻² . (Nearest integer) Given: pK_b(NH₄OH) = 4.74 2 = 0.30 3 = 0. 2026The first and second ionization constants of a weak dibasic acid H₂ A are 8.1 10⁻⁸ and 1.0 10⁻¹³ respectively. 0.1 mol of H₂ A was dissolved in 1 L of 0.1 M HCl solution. The conce 2026At 25°C , 20.0 mL of 0.2 M weak monoprotic acid HX is titrated against 0.2 M NaOH. The pH of the solution (a) at the start of the titration (when NaOH has not been added) and (b) w 2026The solubility product constants of Ag₂CrO₄ and AgBr are 32x and 4y respectively at 298 K. The value of ( molarity of Ag₂CrO₄ molarity of AgBr ) can be expressed as : 2026 Full Ionic Equilibrium list All NTA Abhyas JEE Main PYQs