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

Salts of A (atomic weight 8 ), B (atomic weight 18 ) and C (atomic weight 50 ) were electrolysed under identical conditions using the same quantity of electricity. It was found that 2 . 4   g of A was deposited, the weight of B and C deposited are 1 . 8   g and 7 . 5 g respectively. The valences of A ,   B and C are, respectively,

Options

  1. A3 ,   1 and 2
  2. B1 ,   2 and 3
  3. C1 ,   3 and 2
  4. D3 ,   2 and 1

Correct answer

C. 1 ,   3 and 2

Step-by-step solution

According to the Faraday's law of electrolysis, W = ZQ = E 96500 Q For the compound A , Equivalent mass of A = Atomic   mass Valency = 8 x x is the valency factor for compound A . So, W = E 96500 Q = 8 x 96500 Q x = 7 2 . 4 × 96500 Q For compound B , Equivalent mass of B = Atomic   mass Valency = 18 y y is the valency factor for compound B . So, W = E 96500 Q = 18 y 96500 Q y = 27 1 . 8 × 96500 Q For compound C , Equivalent mass of C = Atomic   mass Valency = 50 z z is the valency facto

Practice Electrochemistry on Quantrex Academy →

More from Electrochemistry

At 300 K, the molar conductivities of the aqueous solutions of three salts at two different concentrations are given below: Salt Concentration (M) Molar conductivity (S cm ^2 mol ⁻ 2026Given at 298 K: E^ _ Fe²⁺/Fe = X Volt; E^ _ Fe³⁺/Fe = Y Volt. The E^ _ Fe³⁺/Fe²⁺ in Volt at 298 K is given by: 2026For a general redox reaction Anode : Red ₁ Ox ₁^ n₁^+ + n₁ e^- Cathode : Ox ₂ + n₂ e^- Red ₂^ n₂^- Which of the following statements is incorrect? 2026Consider the following data. Electrolyte ^ _m (S cm ^2 mol ⁻¹ ) BaCl ₂ x₁ H ₂ SO ₄ x₂ HCl x₃ BaSO ₄ is sparingly soluble in water. If the conductivity of the saturated BaSO ₄ solut 2026One half cell in a voltaic cell is constructed by dipping silver rod in AgNO₃ solution of unknown concentration, other half cell is Zn rod dipped in 1 molar solution of ZnSO₄ . A v 2026At 298 K , the molar conductivity of x % (w/w) MX solution (aqueous) is 123.5 S cm ^2 mol ⁻¹ . The conductance of same solution is 1.9 10⁻³ S . The value of x is _______ 10⁻² . (Gi 2026An electrochemical cell, consist of the following two redox couples, M^ x+ (aq)/M(s)[E_ red ^ =+0.15 V ] and Fe³⁺(aq)/Fe(s)[E_ red ^ =-0.036 V ] . The cell EMF (E_ cell ) is record 2026Consider the following two half-cell reactions along with the standard reduction potential given: CO₂ + 6H^+ + 6e^- CH₃ OH + H₂ O E°_ red = 0.02 V 1 2 O₂ + 2H^+ + 2e^- H₂ O E°_ red 2026 Full Electrochemistry list All 99 Percentile Qs Bank for JEE Main PYQs