Question 1
For a reaction at 300 K, the equilibrium constant is 10 and ΔH° = −11.5 kJ mol⁻¹. What is ΔS° for the reaction? (Take 2.303RT = 5.75 kJ mol⁻¹ at 300 K.)
NEET negative marking: when to answer and when to leave it blank
A correct answer earns 4 marks and an incorrect one loses 1, so a guess between two options you could not split earns 1.5 marks on average, and even a guess among all four earns 0.25. Leave a question blank only when you have a better use for the time.
| Correct | +4 |
|---|---|
| Incorrect | Minus 1 |
| Blank | 0 |
| Our papers | Two 45-question Chemistry papers, marked this way |
The arithmetic of a guess
- Two options left: half the time +4, half the time minus 1, an average of 1.5 marks.
- Three options left: one time in three +4, two in three minus 1, an average of about 0.67 marks.
- All four options left: one in four +4, three in four minus 1, an average of 0.25 marks, with a wide spread.
Where marks are really lost
Most lost marks are not blind guesses but confident wrong answers: an assertion-reason question where the reason was true but did not explain, or a statement misread. Our practice papers show each wrong answer with the reason it was wrong, so you can see which of these costs you most.
Try 2 questions
Question 2
Given below are two statements: one is labelled Assertion A and the other is labelled Reason R.
Assertion A: The second ionisation enthalpy of silicon is higher than that of aluminium, following the general rise across period 3.
Reason R: The Al⁺ ion has the configuration [Ne]3s², while the Si⁺ ion has the configuration [Ne]3s²3p¹.
In the light of the above statements, choose the correct answer.
Next step
Questions people ask
Does a blank answer lose marks in NEET?
No. An unanswered question scores 0. Only a marked incorrect option loses 1 mark.