Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
WBJEE2021ChemistryIonic EquilibriumActual

2.5 ml of 0.4( M ) weak monoacidic base ( k _ b =1 10⁻¹² . at .25^ C ) is titrated with 2 15 ( M ) HCl in water at 25^ C . The concentration of H ⁺ at equivalence point is ( k _ w =1 10⁻¹⁴ . , at .25^ C ) ,

Options

  1. A3.7 10⁻¹³ (M)
  2. B3.2 10⁻⁷( M )
  3. C3.2 10⁻²( M )
  4. D2.7 10⁻²( M )

Correct answer

C. 3.2 10⁻²( M )

Step-by-step solution

N ₁ ~V ₁= N ₂ ~V ₂ (At equivalence point) 0.4 2.5= 2 15 V ₂ BOH ( aq )+ HCl ( aq ) B Cl ⁻( aq )+ H ₂ O (I) V ₂= 0.4 2.5 2 15 = 0.4 2.5 2 15=7.5 ml Concentration of salt = 0.4 2.5 2.5+7.5 or, Salt of weak base and strong acid = 0.1 [ H ⁺ ]= Ch = K _ w C K _ b = 10⁻¹⁴ 0.1 10⁻¹² = 10⁻³ =3.2 10⁻² M as C h²= K_ w K_ b h= K_ w K_ b C

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 WBJEE PYQs