JEE Main2009ChemistryIonic EquilibriumActual
Solid Ba ( NO ₃ )₂ is gradually dissolved in a 1.0 10⁻⁴ M Na ₂ CO ₃ solution. At what concentration of Ba ²⁺ will a precipitate begin to form ? ( K _ sp . for . Ba CO ₃=5.1 10⁻⁹ ) .
Options
- A4.1 10⁻⁵ M
- B5.1 10⁻⁵ M
- C8.1 10⁻⁸ M
- D8.1 10⁻⁷ M
Correct answer
B. 5.1 10⁻⁵ M
Step-by-step solution
aligned & Ba ( NO ₃ )₂+ CaCO ₃ BaCO ₃+2 NaNO ₃ & Here [ CO ₃⁻² ]= [ Na ₂ CO ₃ ]=10⁻⁴ M & K _ sp = [ Ba ⁺² ] [ CO ₃⁻² ] 5.1 10⁻⁹= [ Ba ²⁺ ] (10⁻⁴ ) [ Ba ⁺² ]=5.1 10⁻⁵ aligned At this value, just precipitation starts.