NEET 2027 Chemistry Part 5: Mixed High-Difficulty Practice Questions

NEET 2027
HIGH-WEIGHTAGE CHEMISTRY
PART 5 – SINGLE FILE
200 UNIQUE HIGH-DIFFICULTY MIXED QUESTIONS Numerical • Multi-Concept • Assertion Style • Most
Expected 2027

Zero overlap with Parts 1–4 | Final revision level

Why this Part 5?
✓ 200 brand-new questions – no repeat from any previous part
✓ Mixed high-difficulty style exactly as asked in recent NEET papers
✓ Numerical + conceptual + multi-chapter integration
✓ Single file as requested
✓ Completes your Chemistry practice bank (950 questions total)

, HOW TO USE PART 5
Exam Strategy
1. Attempt 40–50 questions in one sitting under timed conditions (45–50 min).
2. Do not look at answers until you finish the set.
3. Read both ‘why correct’ and ‘why others wrong’ – this is where real learning happens.
4. Note every concept you miss and revise that chapter from Parts 1–4.
5. Repeat weak areas after 3–4 days.

These 200 questions integrate Mole Concept, Atomic Structure, Bonding, Thermodynamics, Equilibrium, Electrochemistry,
Kinetics, Solutions, Coordination, GOC, Hydrocarbons, p-Block, d/f-Block, Alcohols–Carbonyls–Amines, Biomolecules,
Haloalkanes, Solid State, Surface, s-Block, Redox, Environmental and Everyday Chemistry – the full syllabus at NEET difficulty.




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, MIXED HIGH-DIFFICULTY QUESTIONS (Q1–Q200)
Q1. A compound contains 40% C, 6.7% H, 53.3% O. If molar mass is 180, molecular formula is:
A. CH■O
B. C■H■O■
C. C■H■■O■
D. C■H■O■
✓ Correct: C
Why correct: Empirical CH■O (mass 30); n=180/30=6 → C■H■■O■.
✗ Why others wrong:
• A is empirical; B n=2; D n=3.

Q2. Energy of electron in n=2 of H-atom is –3.4 eV. Energy required to excite it to n=3 is:
A. 1.51 eV
B. 3.4 eV
C. 1.89 eV
D. 0.66 eV
✓ Correct: C
Why correct: E■=–13.6/9=–1.51 eV. ∆E=–1.51–(–3.4)=1.89 eV.
✗ Why others wrong:
• A is |E■|; B is |E■|; D incorrect.

Q3. Which has maximum bond angle?
A. H■O
B. H■S
C. H■Se
D. H■Te
✓ Correct: A
Why correct: Bond angle decreases down group 16; H■O largest (~104.5°).
✗ Why others wrong:
• B, C, D progressively smaller.

Q4. For the reaction N■+3H■■2NH■, K■=K_c(RT)^x. Value of x is:
A. +2
B. –2
C. +1
D. 0
✓ Correct: B
Why correct: ∆n_g=2–4=–2 → K■=K_c(RT)^(–2).
✗ Why others wrong:
• A wrong sign; C, D wrong ∆n.

Q5. E°_cell for Zn|Zn²■||Cu²■|Cu is 1.10 V. ∆G° is approximately:
A. –212 kJ
B. +212 kJ
C. –106 kJ
D. 0
✓ Correct: A
Why correct: ∆G°=–nFE°=–2×96500×1.10≈–212300 J=–212 kJ.
✗ Why others wrong:
• B wrong sign; C for n=1.

Q6. Half-life of a first-order reaction is 10 min. Time for 99.9% completion is about:
A. 50 min
B. 100 min
C. 20 min
D. 10 min
✓ Correct: B
Why correct: 99.9% ≈ 10 half-lives → 10×10=100 min.
✗ Why others wrong:
• A is 5 half-lives (≈97%); C, D too short.

Q7. 0.1 M glucose and 0.1 M NaCl – which has higher osmotic pressure?
A. Glucose
B. NaCl
C. Equal
D. Cannot say




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, ✓ Correct: B
Why correct: NaCl i≈2 → effective concentration higher → higher π.
✗ Why others wrong:
• A i=1; C false.

Q8. [Ni(CN)■]²■ is diamagnetic. Hybridisation is:
A. sp³
B. dsp²
C. sp³d²
D. d²sp³
✓ Correct: B
Why correct: Square planar, diamagnetic → dsp².
✗ Why others wrong:
• A tetrahedral paramagnetic; C, D octahedral.

Q9. Most stable carbocation:
A. CH■■
B. (CH■)■CH■
C. (CH■)■C■
D. CH■CH■■
✓ Correct: C
Why correct: 3° carbocation maximum +I and hyperconjugation.
✗ Why others wrong:
• A methyl; B 2°; D 1°.

Q10. Which is aromatic?
A. Cyclobutadiene
B. Cyclooctatetraene
C. Pyridine
D. Cyclopropene
✓ Correct: C
Why correct: Pyridine: 6π, planar, Hückel (4n+2).
✗ Why others wrong:
• A, B anti/non-aromatic; D not aromatic.

Q11. ON of Cr in K■Cr■O■:
A. +3
B. +6
C. +4
D. +7
✓ Correct: B
Why correct: 2x+7(–2)=–2 → x=+6.
✗ Why others wrong:
• A, C, D do not balance.

Q12. Packing efficiency of bcc:
A. 52%
B. 68%
C. 74%
D. 90%
✓ Correct: B
Why correct: bcc packing efficiency ≈68%.
✗ Why others wrong:
• A sc; C fcc/hcp.

Q13. Hardy–Schulze: highest coagulating power for negative sol:
A. Na■
B. Ba²■
C. Al³■
D. Equal
✓ Correct: C
Why correct: Higher charge → higher coagulating power: Al³■>Ba²■>Na■.
✗ Why others wrong:
• A, B lower charge.

Q14. Temporary hardness removed by:



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