JEE Main 2018ChemistryIonic EquilibriumMediumMCQ

JEE Main 2018 — Ionic Equilibrium Question with Solution

JEE Main 2018 (08 Apr)

Question

An aqueous solution contains an unknown concentration of Ba2+. When 50 mL of a 1 M solution of Na2SO4 is added, BaSO4 just begins to precipitate. The final volume is 500 mL. The solubility product of BaSO4 is 1×10-10. What is the original concentration of Ba2+?

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Show full solutionCorrect option: D
Correct answer
D1.1×10-9M

Step-by-step explanation

Ba+2+SO42−⇌BaSO4(s)ppt

Final conc. of [SO42−]=MV1V1+V2=1×50500=0.1M

Final conc.of [Ba+2] When BaSO4 start precipitating

KSP=QSP=[Ba+2][SO42−]

10−10=[Ba+2](0.1M)

Initial conc. [Ba+2]; initial volume was =500-50=450 ml
M1V1=M2V2

M1=M2V2V1=10−9×500450

M1=1.1×10−9M
 

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About this question

This is a previous-year question from JEE Main 2018, covering the Ionic Equilibrium chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.