BITSAT2014ChemistryIonic EquilibriumActual
K_ c for the the reaction, [ Ag ( CN )₂ ] Ag ⁺+2 CN ⁻, the equillibrium constant at 25^ C is 4.0 10⁻¹⁹ then the silver ion concentration in a solution which was originally 0.1 molar in KCN and 0.03 molar in AgNO ₃ is:
Options
- A7.5 10¹⁸
- B7.5 10⁻¹⁹
- C7.5 10¹⁹
- D7.5 10⁻¹⁸
Correct answer
D. 7.5 10⁻¹⁸
Step-by-step solution
. array c 2 KCN + AgNO = [ 0.1 0.03 = [ array c Ag ( CN )₂ 0 array ]⁻ . (0.1-0.06) & 0 array ] array c KNO ₃+ K ₀⁺ (0.03) array [ Ag ( CN )₂ ]⁻= Ag ⁺+ a 0.03 a 2 CN (0.03- a ) a .04( left from KCN 0.04 0.04 K _ c =4 10⁻¹⁹= (0.04)² a 0.03 a =7.5 10⁻¹⁸