Chapters
Ionic Equilibrium
WeakBehind the roomChemistry · Physical · 36% · 5/12 in 60 days · last 8 Nov
In his tests
36%
5 of 14 right · room 47%
Chapter tests
–
Past papers
8/10
4 right · 1 wrong · 0 starred
Revisions
0
none yet
Marks lost
−7
to wrong answers in tests
Time a question
2m 21s
average in tests
Against the room
Share right on these exact questions, in his tests. His batch is the closer comparison.Him
36%
His batch
47%
Everyone who sat it
47%
Why they went wrong
His reasons on 7 of 13 not right.
Concept gap 4Careless 1Time trap 2
Chapter tests and sets
Chapter tests and the sets sat in Plus4 on this chapter. The score is his questions on this chapter only. Tap one to go over it.1 sitting, newest first
Short notes
Formulas, traps, what to remember. Every version is kept. The coach adds a trap when his tests show one the note misses, and says why.Revised by the coach 14 Nov: Added the trap from the buffer doubt · 2 versions
1 · Formulas and when each holds
- pH = −log[H⁺]; pH + pOH = 14 at 25 °C.
- Weak acid: [H⁺] = √(Ka·C), when the degree of dissociation is small.
- Buffer (Henderson): pH = pKa + log([salt]/[acid]).
- Salt of weak acid and strong base: pH = 7 + ½(pKa + log C).
2 · Question types and the first step
- Buffer questions: find the ratio of salt to acid before anything else.
- Solubility product: write s in terms of Ksp from the formula of the salt.
3 · Traps
Common ion: solubility falls in a solution that already holds one of the ions.
Buffer on dilution: he diluted the acid alone. Rule: dilution changes salt and acid equally, so the ratio and the pH stay.
4 · My additions
- Check the temperature before using 14.
Full revision notes
The whole NCERT chapter at about a quarter of its length, with what JEE Main adds beyond the book. For a proper revision pass; the short note above is for the last week.5,477 words · about 27 min
His questions on this chapter
Newest first. Tap a question to open it.22 from tests and sets · 13 not right
Every time it came up
6 Sep 2026
20 Sep 2026
27 Sep 2026
4 Oct 2026
18 Oct 2026
25 Oct 2026
1 Nov 2026
3 Nov 2026
8 Nov 2026
RightWrongSkippedStarredToo few to read a trend into: read the dots, not a slope.
Concept gaps
A gap closes only when he answers an unseen question on it right, on a later day.1 open
- pH of a buffer after dilutionOpenFound 14 Nov in a doubt · 4 marks at risk2 check questions named; not tried yet.
His doubts
Newest first, as the coach logged them.1 on this chapter
- Why the pH of a buffer barely changes when it is dilutedSolution given14 Nov · Class module, ionic equilibrium exercise · Concept gap · pH of a buffer after dilution · 3 steps of help · 18 minHe had tried: Diluted the acid alone and recomputed its pH.Worked solution given: A class test on the chapter is two days away.The key idea, in his words: pH depends on the ratio of salt to acid; dilution changes both equally.
The whole conversation
- Where he stopped: treated the buffer as the acid alone.
- Hint 1: what does the Henderson equation depend on? He wrote it out.
- Hint 2: what happens to that ratio on dilution? Not yet clear to him.
- Worked solution given: the class test is close; the twin set checks it tomorrow.
Revisions
None logged.