JEE Main Pattern Practice Questions

Stop Reading. Start Scoring.

Sections 1 to 16 taught the chapter. They gave you the equilibrium constant and the algebra that reverses, scales and adds it, the conversion between $K_p$ and $K_c$, the ICE table, the reaction quotient, the link to $\Delta G^{\circ}$, Le Chatelier's principle with its inert-gas trap, the pH scale, $K_a$ and $K_b$, Ostwald's dilution law, hydrolysis, buffers and the solubility product. That was the teaching half.

This section is the other half. It finds out whether you can use any of it with a clock running.

That gap is real and it is where marks are lost. A student who can derive $K_p = K_c(RT)^{\Delta n}$ on a quiet afternoon still writes $\Delta n = +2$ for ammonia synthesis at minute thirty of a paper. A student who knows Henderson-Hasselbalch still puts acid over salt. The only way to find your own version of that gap is to sit an actual timed set and then look at what you got wrong.

Key Point: Sit with a blank sheet, a pen and a timer. Attempt all 30 questions in one unbroken sitting, writing down a choice for every question you attempt, before you read a single explanation. Peeking at an explanation halfway through converts a diagnostic test into a reading exercise, and a reading exercise tells you nothing about what you can do under pressure.

Two rules make the negative marking work for you rather than against you. First, a question you have narrowed to two options is worth attempting: a coin flip between two options returns $+1.5$ on average. A question where all four still look possible is worth leaving, because a blind guess returns $+0.25$ and costs you the eighty seconds you spent on it. Second, when a calculation stalls, mark the question and move on. Equilibrium papers are full of two-line questions sitting behind a four-line one, and the commonest way to lose twenty marks is to spend nine minutes on a cubic.

No tables are allowed, so carry these log values in your head: $\log 2 = 0.301$, $\log 3 = 0.477$, $\log 5 = 0.699$, $\log 5.9 = 0.771$, $\log 6 = 0.778$, $\log 7 = 0.845$. Most of the pH arithmetic in this set reduces to one of those.

[JEE Main] Keep your working on the rough sheet in question order and number it. When you mark yourself, the working is what tells you whether a wrong answer was a concept you do not have or an arithmetic slip you can fix in a week.

How to mark yourself

Apply the scheme exactly: $+4$, $-1$, $0$. Do not give yourself credit for a question you would have got right with thirty more seconds, and do not excuse a sign error as carelessness. Sign errors on $\Delta n$ and on $\Delta G^{\circ}$ are concept errors wearing a disguise.

A negative or near-zero total almost always means over-attempting rather than not knowing. Count how many you attempted. If you attempted twenty-eight and scored under forty, the fix is selection, not content.

Now the part that actually raises your score. Take every question you got wrong and write next to it the section it came from, using the tags on the explanation. Wrong answers cluster. Six wrong answers scattered across six topics is an arithmetic problem and a week of drilling fixes it. Six wrong answers all sitting in hydrolysis and buffers is a concept hole, and no amount of extra questions will fill it until you go back and reread section 13. Read the full explanation for every wrong answer, including the sentence that says which slip produces the option you chose, and then check whether that slip is the one you actually made. Often it is not, and that is the more useful discovery.

One last habit. For every question you got right by elimination rather than by working, mark it. Those are the ones that will turn into wrong answers when the same idea appears with different numbers.