JEE Main2010ChemistryIonic EquilibriumActual
Solubility product of silver bromide is 5.0 10⁻¹³ . The quantity of potassium bromide (molar mass precipitation of AgBr is
Options
- A1.2 10⁻¹⁰ ~g
- B1.2 10⁻⁹ ~g
- C6.2 10⁻⁵ ~g
- D5.0 10⁻⁸ ~g
Correct answer
B. 1.2 10⁻⁹ ~g
Step-by-step solution
Ag ⁺+ Br ⁻ AgBr Precipitation starts when ionic product just exceeds solubility product aligned & K _ sp = [ Ag ⁺ ] [ Br ⁻ ] & [ Br ⁻ ]= K _ sp [ Ag ⁺ ] = 5 10⁻¹³ 0.05 =10⁻¹¹ aligned i.e., precipitation just starts when 10⁻¹¹ moles of KBr is added to 1 ~L of AgNO ₃ solution. No. of moles of KBr to be added aligned weight of KBr to be added & =10⁻¹¹ 120 & =1.2 10⁻⁹ ~g aligned