COMEDK2024Morning ShiftChemistryElectrochemistryActual
Given below are 4 equations showing Molar conductivities at infinite dilution of various electrolytes. Which one of them represents the correct equation? aligned & ( _m^0 )_ N a B r - ( _m^0 )_ N a C l = ( _m^0 )_ KCl - ( _m^0 )_ KBr & ( _m^0 )_ HCl + ( _m^0 )_ KOH - ( _m^0 )_ KCl = ( _m^0 )_ H ₂ O & ( _m^0 )_ KBr - ( _m^0 )_ NaBr = ( _m^0 )_ NaBr - ( _m^0 )_ Nal & ( _m^0 )_ N H₄ Cl - ( _m^0 )_ NH ₄ NO ₃ = ( _m^0 )_
Options
- AEquation 4
- BEquation 1
- CEquation 2
- DEquation 3
Correct answer
C. Equation 2
Step-by-step solution
Using Kohlrausch's law, expanding Equation 2 LHS: (A^0_m)_ HCl + (A^0_m)_ KOH - (A^0_m)_ KCl = [ ^0(H^+) + ^0(Cl^-)] + [ ^0(K^+) + ^0(OH^-)] - [ ^0(K^+) + ^0(Cl^-)] = ^0(H^+) + ^0(OH^-) = (A^0_m)_ H₂O = RHS Equation 2 is correct. The cancellation of ^0(Cl^-) and ^0(K^+) on both sides confirms LHS = RHS.