Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
99 Percentile Qs Bank for JEE MainChemistryIonic Equilibrium

The heats of neutralization of CH 3 COOH ,   HCOOH ,   HCN   and H 2 S are - 13 . 2 ,   - 13 . 4 ,   - 2 . 9 and - 3 . 8 kcal per equivalent respectively. The correct increasing order of acid strength is

Options

  1. AHCOOH < CH 3 COOH < H 2 S < HCN .
  2. BHCN < H 2 S < CH 3 COOH < HCOOH .
  3. CHCOOH < CH 3 COOH < HCN < H 2 S .
  4. DCH 3 COOH < H 2 S < HCN < HCOOH .

Correct answer

B. HCN < H 2 S < CH 3 COOH < HCOOH .

Step-by-step solution

Δ H ionisation = Δ H neutralisation experimental - Δ H neutral theoretical Δ H ionisation CH 3 COOH = - 13.20 + 13.75 = 0.55  kcal  mol - 1 Δ H ionisation HCOOH = - 13.40 + 13.75 = 0.35  kcal  mol - 1 Δ H ionisation HCN = - 2.90 + 13.75 = 10.85  kcal  mol - 1 Δ H ionisation H 2 S = - 3.80 + 13.75 = 9.95  kcal  mol - 1 - 13 . 75   kcal   mol - 1 is the standard enthalpy of neutralisation for strong acid or a strong base. Higher the

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 99 Percentile Qs Bank for JEE Main PYQs