“Chemistry plays a crucial role in NEET preparation, as it forms a strong link between Physics and Biology. Practicing previous year questions and topic-wise problems not only helps in understanding concepts but also improves accuracy and speed. This collection of NEET Chemistry questions and answers is designed to strengthen your fundamentals, clear doubts, and boost your confidence for the exam.”
Chemistry questions and answers
PART I
1. Who is the father of modern chemistry?
Antoine Lavoisier
2. Who proposed atomic theory?
John Dalton
3. Smallest particle of an element that retains its properties?
Atom
4. Subatomic particle with negative charge?
Electron
5. Subatomic particle with positive charge?
Proton
6. Subatomic particle with no charge?
Neutron
7. Who discovered electron?
J.J. Thomson
8. Who discovered proton?
Goldstein
9. Who discovered neutron?
James Chadwick
10. Who proposed planetary model of atom?
Niels Bohr
11. Number of protons in an atom is called?
Atomic number
12. Sum of protons and neutrons is called?
Mass number
13. Atoms of same element with different mass numbers are called?
Isotopes
14. Atoms of different elements with same mass number are called?
Isobars
15. Atoms with same number of neutrons are called?
Isotones
16. First element in the periodic table?
Hydrogen
17. Lightest gas?
Hydrogen
18. Most abundant element in the universe?
Hydrogen
19. Most abundant element in earth’s crust?
Oxygen
20. Most abundant element in human body?
Oxygen
21. Which element is known as “King of chemicals”?
Sulphuric acid (H₂SO₄)
22. Which acid is called “aqua fortis”?
Nitric acid (HNO₃)
23. Which acid is called “oil of vitriol”?
Sulphuric acid (H₂SO₄)
24. Which acid is present in vinegar?
Acetic acid
25. Which acid is present in lemon?
Citric acid
26. Which acid is present in curd?
Lactic acid
27. Which acid is present in apple?
Malic acid
28. Which acid is present in tomato?
Oxalic acid
29. Which acid is present in ant sting?
Formic acid
30. Which acid is present in grapes?
Tartaric acid
31. pH of pure water at 25°C?
7
32. pH of human blood?
About 7.4
33. Instrument used to measure pH?
pH meter
34. Logarithm of hydrogen ion concentration is called?
pH
35. A substance which turns red litmus blue?
Base
36. A substance which turns blue litmus red?
Acid
37. Which gas is known as “laughing gas”?
Nitrous oxide (N₂O)
38. Which gas is known as “marsh gas”?
Methane (CH₄)
39. Which gas is known as “tear gas”?
Chloropicrin (CCl₃NO₂)
40. Which gas is used in balloons?
Helium
41. Which gas is used in advertisements and neon signs?
Neon
42. Which gas is used in welding?
Acetylene (C₂H₂)
43. Which gas is used for ripening of fruits?
Ethylene
44. Which gas is produced during photosynthesis?
Oxygen
45. Which gas is produced during respiration?
Carbon dioxide
46. Which gas is produced during fermentation?
Carbon dioxide
47. Which gas is called “greenhouse gas”?
Carbon dioxide
48. Which gas is known as “ozone layer gas”?
Ozone (O₃)
49. Which gas is responsible for acid rain?
Sulphur dioxide (SO₂)
50. Which gas is responsible for Bhopal gas tragedy?
Methyl isocyanate (MIC)
51. Who gave the law of constant proportions?
Joseph Proust
52. Who gave the law of multiple proportions?
Dalton
53. Who gave the periodic law?
Mendeleev
54. Modern periodic law is based on?
Atomic number
55. Periodicity in properties occurs after?
Same number of electrons in outer shell
56. Which element is most electronegative?
Fluorine
57. Which element is least electronegative?
Francium
58. Which element has maximum ionization energy?
Helium
59. Which element has minimum ionization energy?
Francium
60. Which element has largest atomic radius?
Francium
61. Which element has smallest atomic radius?
Helium
62. Which element has highest electron affinity?
Chlorine
63. Which element has lowest electron affinity?
Francium
64. Which element has maximum metallic character?
Francium
65. Which element has maximum non-metallic character?
Fluorine
66. Which is most reactive alkali metal?
Francium
67. Which is least reactive halogen?
Iodine
68. Which halogen is used in water purification?
Chlorine
69. Which noble gas is used in lamps?
Neon
70. Which noble gas is used in high-voltage electric bulbs?
Argon
71. Which element is liquid at room temperature?
Mercury (Hg) and Bromine (Br₂)
72. Atomic number of Oxygen?
8
73. Atomic number of Hydrogen?
1
74. Atomic number of Carbon?
6
75. Atomic number of Nitrogen?
7
76. Atomic number of Sodium?
11
77. Atomic number of Magnesium?
12
78. Atomic number of Aluminium?
13
79. Atomic number of Silicon?
14
80. Atomic number of Phosphorus?
15
81. Atomic number of Sulfur?
16
82. Atomic number of Chlorine?
17
83. Atomic number of Argon?
18
84. Atomic number of Potassium?
19
85. Atomic number of Calcium?
2
86. Who proposed octet rule?
Gilbert Lewis
87. Valency of Hydrogen?
1
88. Valency of Oxygen?
2
89. Valency of Nitrogen?
3
90. Valency of Carbon?
4
91. Valency of Sulfur?
2, 4, or 6 (depends on compound)
92. Valency of Chlorine?
1
93. Valency of Phosphorus?
3 or 5
94. Valency of Sodium?
1
95. Valency of Magnesium?
2
96. Valency of Aluminium?
3
97. Valency of Silicon?
4
98. Who gave law of electrolysis?
Faraday
99. Faraday’s first law of electrolysis?
Mass of substance deposited ∝ Charge passed
100. Faraday’s second law of electrolysis?
Mass of substances deposited by same quantity of electricity ∝ Equivalent weight
Part II
101. Who discovered the electron?
J.J. Thomson
102. Who proposed the plum pudding model of atom?
J.J. Thomson
103. Who proposed Rutherford model of atom?
Ernest Rutherford
104. Who proposed Bohr’s model of atom?
Niels Bohr
105. Bohr’s model explains which spectrum?
Hydrogen atomic spectrum
106. Atomic number = ?
Number of protons in nucleus
107. Mass number = ?
Protons + Neutrons
108. Isotopes have same?
Atomic number
109. Isotopes have different?
Mass number
110. Isobars have same?
Mass number
111. Isobars have different?
Atomic number
112. Electronic configuration of Oxygen (Z=8)?
1s² 2s² 2p⁴
113. Electronic configuration of Carbon (Z=6)?
1s² 2s² 2p²
114. Electronic configuration of Sodium (Z=11)?
1s² 2s² 2p⁶ 3s¹
115. Electronic configuration of Chlorine (Z=17)?
1s² 2s² 2p⁶ 3s² 3p⁵
116. Electronic configuration of Magnesium (Z=12)?
1s² 2s² 2p⁶ 3s²
117. Electronic configuration of Aluminium (Z=13)?
1s² 2s² 2p⁶ 3s² 3p¹
118. Electronic configuration of Fluorine (Z=9)?
1s² 2s² 2p⁵
119. Electronic configuration of Neon (Z=10)?
1s² 2s² 2p⁶
120. What is ionization energy?
Energy required to remove an electron from gaseous atom
121. What is electron affinity?
Energy change when an atom gains an electron
122. Electronegativity of Fluorine?
4.0 (highest)
123. Electronegativity of Francium?
0.7 (lowest)
124. Which element has maximum metallic character?
Francium
125. Which element has maximum non-metallic character?
Fluorine
126. Which is the most reactive alkali metal?
Francium
127. Which is the least reactive halogen?
Iodine
128. Which halogen is used in water purification?
Chlorine
129. Which noble gas is used in lamps and signboards?
Neon
130. Which noble gas is used in high-voltage electric bulbs?
Argon
131. Which is the only metal that is liquid at room temperature?
Mercury (Hg)
132. Which is the only non-metal that is liquid at room temperature?
Bromine (Br₂)
133. Atomic mass of Carbon?
12 u
134. Atomic mass of Hydrogen?
1 u
135. Atomic mass of Oxygen?
16 u
136. Atomic mass of Nitrogen?
14 u
137. Valency of Hydrogen?
1
138. Valency of Oxygen?
2
139. Valency of Carbon?
4
140. Valency of Nitrogen?
3
141. Valency of Sulfur?
2, 4, or 6 (depends on compound)
142. Valency of Phosphorus?
3 or 5
143. Valency of Chlorine?
1
144. Valency of Sodium?
1
145. Valency of Magnesium?
2
146. Valency of Aluminium?
3
147. Valency of Silicon?
4
148. Who gave Faraday’s laws of electrolysis?
Michael Faraday
149. Faraday’s first law states?
Mass of substance deposited ∝ Charge passed
150. Faraday’s second law states?
Mass of substances deposited by same quantity of electricity ∝ Equivalent weight
151. What is electrolysis?
Decomposition of a compound using electricity
152. Unit of electric current?
Ampere (A)
153. Unit of electric charge?
Coulomb (C)
154. Unit of resistance?
Ohm (Ω)
155. Unit of potential difference?
Volt (V)
156. Unit of capacitance?
Farad (F)
157. Unit of magnetic field?
Tesla (T)
158. Unit of inductance?
Henry (H)
159. Law of constant composition states?
A compound always contains the same proportion of elements by mass
160. Law of multiple proportions states?
Elements combine in small whole number ratios to form different compounds
161. Who proposed periodic law?
Mendeleev
162. Modern periodic law is based on?
Atomic number
163. Group in periodic table represents?
Number of valence electrons
164. Period in periodic table represents?
Number of shells
165. Most reactive alkali metal?
Francium
166. Most reactive halogen?
Fluorine
167. Most electronegative element?
Fluorine
168. Least electronegative element?
Francium
169. Element with highest ionization energy?
Helium
170. Element with lowest ionization energy?
Francium
171. Element with largest atomic radius?
Francium
172. Element with smallest atomic radius?
Helium
173. Element with maximum metallic character?
Francium
174. Element with maximum non-metallic character?
Fluorine
175. Which element is used in nuclear reactors as moderator?
Carbon (graphite)
176. Which element is used as control rods in nuclear reactors?
Cadmium
177. Which element is used in thermite reaction?
Aluminium
178. Which element is used in Bunsen burner flame test for red color?
Strontium
179. Which element is used in Bunsen burner flame test for yellow color?
Sodium
180. Which element is used in Bunsen burner flame test for violet color?
Potassium
181. Which element is used in Bunsen burner flame test for green color?
Copper
182. Which acid is called “aqua regia”?
Mixture of HCl and HNO₃ in 3:1 ratio
183. Which acid is called “oil of vitriol”?
Sulphuric acid (H₂SO₄)
184. Which acid is found in vinegar?
Acetic acid (CH₃COOH)
185. Which acid is found in lemon?
Citric acid
186. Which acid is found in tomato?
Oxalic acid
187. Which acid is found in apple?
Malic acid
188. Which base is used in soap making?
Sodium hydroxide (NaOH)
189. Which base is used in paper industry?
Calcium hydroxide [Ca(OH)₂]
190. Which base is used in water purification?
Calcium hydroxide [Ca(OH)₂]
191. Which base is used in baking powder?
Sodium bicarbonate (NaHCO₃)
192. pH of neutral solution?
7
193. pH of human blood?
About 7.4
194. pH of strong acid?
Less than 7
195. pH of strong base?
Greater than 7
196. Which gas is known as laughing gas?
Nitrous oxide (N₂O)
197. Which gas is known as marsh gas?
Methane (CH₄)
198. Which gas is known as tear gas?
Chloropicrin (CCl₃NO₂)
199. Which gas is used for ripening fruits?
Ethylene (C₂H₄)
200. Which gas caused Bhopal gas tragedy?
Methyl isocyanate (MIC)
Part III
201. Which element is most abundant in Earth's crust?
Oxygen
202. Which element is most abundant in human body?
Oxygen
203. Which element is used in light bulbs?
Tungsten
204. Which element is used in thermometers?
Mercury
205. Which element is used in nuclear reactors as fuel?
Uranium-235
206. Which element is used in photography?
Silver (Ag)
207. Which element is used in matches?
Phosphorus
208. Which element is used in fireworks?
Aluminium, Strontium, Barium, Magnesium (for colors)
209. Which is the most reactive alkali metal?
Francium
210. Which is the least reactive alkali metal?
Lithium
211. Which is the most reactive halogen?
Fluorine
212. Which is the least reactive halogen?
Iodine
213. Which noble gas is used in electric lamps?
Argon
214. Which noble gas is used in neon signs?
Neon
215. Which noble gas is most abundant in atmosphere?
Argon
216. Which compound is called “baking soda”?
Sodium bicarbonate (NaHCO₃)
217. Which compound is called “washing soda”?
Sodium carbonate (Na₂CO₃·10H₂O)
218. Which compound is called “slaked lime”?
Calcium hydroxide [Ca(OH)₂]
219. Which compound is called “quick lime”?
Calcium oxide (CaO)
220. Which acid is called “aqua regia”?
Mixture of HCl and HNO₃ in 3:1 ratio
221. Which acid is called “milk of magnesia”?
Magnesium hydroxide [Mg(OH)₂]
222. Which acid is called “oil of vitriol”?
Sulphuric acid (H₂SO₄)
223. Which acid is found in vinegar?
Acetic acid (CH₃COOH)
224. Which acid is found in lemon juice?
Citric acid
225. Which acid is found in tamarind?
Tartaric acid
226. Which acid is found in tomato?
Oxalic acid
227. Which acid is found in apple?
Malic acid
228. Which base is used in soap making?
Sodium hydroxide (NaOH)
229. Which base is used in water purification?
Calcium hydroxide [Ca(OH)₂]
230. Which base is used in baking powder?
Sodium bicarbonate (NaHCO₃)
231. Strong acid examples?
HCl, H₂SO₄, HNO₃
232. Strong base examples?
NaOH, KOH
233. Weak acid examples?
CH₃COOH, H₂CO₃
234. Weak base examples?
NH₄OH
235. pH of neutral solution?
7
236. pH of strong acid?
<7
237. pH of strong base?
>7
238. Electrolysis of water produces?
Hydrogen at cathode, Oxygen at anode
239. Faraday’s first law of electrolysis?
Mass of substance ∝ Quantity of electricity
240. Faraday’s second law of electrolysis?
Masses of substances ∝ Equivalent weight
241. Unit of electric current?
Ampere (A)
242. Unit of electric charge?
Coulomb (C)
243. Unit of resistance?
Ohm (Ω)
244. Unit of potential difference?
Volt (V)
245. Unit of capacitance?
Farad (F)
246. Unit of magnetic field?
Tesla (T)
247. Unit of inductance?
Henry (H)
248. Ohm’s law states?
V = IR
249. Resistance of a conductor depends on?
Length, cross-sectional area, material, temperature
250. Conductors and insulators examples?
Copper, Aluminum – Conductors; Glass, Ru
bber – Insulators
251. Which gas is liberated when acids react with metals?
Hydrogen (H₂)
252. Which gas is liberated when H₂CO₃ decomposes?
Carbon dioxide (CO₂)
253. Which gas is liberated when NaHCO₃ reacts with acid?
Carbon dioxide (CO₂)
254. Which gas is liberated in thermal decomposition of KClO₃?
Oxygen (O₂)
255. Which gas is responsible for global warming?
Carbon dioxide (CO₂)
256. Which gas is responsible for ozone layer depletion?
Chlorofluorocarbons (CFCs)
257. Which gas is used in welding?
Acetylene (C₂H₂)
258. Which gas is used in refrigerators?
Ammonia (NH₃)
259. Which gas is used in balloons?
Helium (He)
260. Which gas is used in fluorescent lamps?
Mercury vapor (Hg)
261. Which gas is used in fire extinguishers?
Carbon dioxide (CO₂)
262. Which gas is used in photosynthesis experiments?
Carbon dioxide (CO₂)
263. Which gas is produced in fermentation?
Carbon dioxide (CO₂) and Ethanol (C₂H₅OH)
264. Which gas is produced in respiration?
Carbon dioxide (CO₂)
265. Which gas is produced in combustion of hydrocarbons?
Carbon dioxide (CO₂) and Water (H₂O)
266. Which gas is toxic and colorless, produced in incomplete combustion?
Carbon monoxide (CO)
267. Which gas is used in greenhouses to enhance plant growth?
Carbon dioxide (CO₂)
268. Which gas is used to inflate aircraft tires?
Nitrogen (N₂)
269. Which gas is used in making fertilizers?
Ammonia (NH₃)
270. Which gas is liberated in photosynthesis?
Oxygen (O₂)
271. Which gas is used in acid rain studies?
Sulfur dioxide (SO₂)
272. Which gas is used in the Haber process?
Nitrogen (N₂) and Hydrogen (H₂)
273. Which gas is used in production of nitric acid?
Nitrogen dioxide (NO₂)
274. Which gas is called laughing gas?
Nitrous oxide (N₂O)
275. Which gas is used in sterilization?
Ethyl
ene oxide (C₂H₄O)
276. Which is the most electronegative element?
Fluorine (F)
277. Which element has the lowest electronegativity?
Francium (Fr)
278. Which element has highest ionization energy?
Helium (He)
279. Which element has lowest ionization energy?
Cesium (Cs)
280. Which element has highest electron affinity?
Chlorine (Cl)
281. Which element has lowest electron affinity?
Noble gases (He, Ne, etc.)
282. Which element has largest atomic radius?
Francium (Fr)
283. Which element has smallest atomic radius?
Helium (He)
284. Which element is most metallic?
Francium (Fr)
285. Which element is least metallic?
Fluorine (F)
286. Which element is called lightest metal?
Lithium (Li)
287. Which element is called heaviest metal?
Osmium (Os)
288. Which element is used in atomic clocks?
Cesium (Cs)
289. Which element is used in water softening?
Calcium (Ca)
290. Which element is used in antiseptics?
Iodine (I)
291. Which element is used in balloons and airships?
Helium (He)
292. Which element is used in making dry cell batteries?
Zinc (Zn)
293. Which element is used in making light bulbs?
Tungsten (W)
294. Which element is used in nuclear reactors as moderator?
Graphite (Carbon, C)
295. Which element is used in fertilizer production?
Nitrogen (N)
296. Which element is used in making thermite mixture?
Aluminium (Al)
297. Which element is used in fireworks for red color?
Strontium (Sr)
298. Which element is used in fireworks for green color?
Barium (Ba)
299. Which element is used in fireworks for yellow color?
Sodium (Na)
300. Which element is used in antiseptic solution “tincture of iodine”?
Iodine (I)
Part IV
301. Which element is most electronegative?
Fluorine (F)
302. Which element has lowest electronegativity?
Francium (Fr)
303. Which element has highest ionization energy?
Helium (He)
304. Which element has lowest ionization energy?
Cesium (Cs)
305. Which element has highest electron affinity?
Chlorine (Cl)
306. Which element has lowest electron affinity?
Noble gases
307. Which element has largest atomic radius?
Francium (Fr)
308. Which element has smallest atomic radius?
Helium (He)
309. Which element is most metallic?
Francium (Fr)
310. Which element is least metallic?
Fluorine (F)
311. Lightest metal?
Lithium (Li)
312. Heaviest metal?
Osmium (Os)
313. Element used in atomic clocks?
Cesium (Cs)
314. Element used in water softening?
Calcium (Ca)
315. Element used in antiseptics?
Iodine (I)
316. Element used in balloons and airships?
Helium (He)
317. Element used in dry cell batteries?
Zinc (Zn)
318. Element used in light bulbs?
Tungsten (W)
319. Element used in nuclear reactors as moderator?
Graphite (C)
320. Element used in fertilizer production?
Nitrogen (N)
321. Element used in thermite mixture?
Aluminium (Al)
322. Element in fireworks for red color?
Strontium (Sr)
323. Element in fireworks for green color?
Barium (Ba)
324. Element in fireworks for yellow color?
Sodium (Na)
325. Element in “tincture of iodine”?
Iodine (I)
326. What is the valency of hydrogen?
1
327. What is the valency of oxygen?
2
328. What is the valency of nitrogen?
3
329. What is the valency of carbon?
4
330. What is the valency of chlorine?
1
331. Which is the lightest noble gas?
Helium (He)
332. Which is the heaviest noble gas?
Radon (Rn)
333. Which metal reacts vigorously with water?
Potassium (K)
334. Which metal is least reactive with water?
Gold (Au)
335. Which gas is used in making ammonia?
Nitrogen (N₂)
336. Which gas is used in making nitric acid?
Nitrogen dioxide (NO₂)
337. Which metal is used in galvanization?
Zinc (Zn)
338. Which metal is liquid at room temperature?
Mercury (Hg)
339. Which non-metal is used in matches?
Phosphorus (P)
340. Which non-metal is used in water purification?
Chlorine (Cl₂)
341. Which acid is present in stomach?
Hydrochloric acid (HCl)
342. Which acid is called oil of vitriol?
Sulfuric acid (H₂SO₄)
343. Which acid is called aqua regia?
Mixture of HCl + HNO₃ (3:1)
344. Which base is used in soap making?
Sodium hydroxide (NaOH)
345. Which base is used in water purification?
Calcium hydroxide [Ca(OH)₂]
346. Which base is used in baking powder?
Sodium bicarbonate (NaHCO₃)
347. pH of neutral solution?
7
348. pH of acidic solution?
<7
349. pH of basic solution?
>7
350. Strong acid examples?
HCl, H₂SO₄, HNO₃
351. Strong base examples?
NaOH, KOH
352. Weak acid examples?
CH₃COOH, H₂CO₃
353. Weak base examples?
NH₄OH, CH₃NH₂
354. Neutralization reaction produces?
Salt + Water
355. Example of neutralization reaction?
HCl + NaOH → NaCl + H₂O
356. Salt formed from strong acid and strong base?
Neutral salt (e.g., NaCl)
357. Salt formed from strong acid and weak base?
Acidic salt (e.g., NH₄Cl)
358. Salt formed from weak acid and strong base?
Basic salt (e.g., Na₂CO₃)
359. Electrolysis of water produces?
H₂ at cathode, O₂ at anode
360. Electrolysis of NaCl (brine) produces?
Cl₂ at anode, H₂ at cathode, NaOH in solution
361. Faraday’s first law of electrolysis?
Mass ∝ Charge
362. Faraday’s second law of electrolysis?
Mass ∝ Equivalent weight
363. Unit of conductivity?
Siemens/m (S/m)
364. Strong electrolyte example?
HCl, NaOH
365. Weak electrolyte example?
CH₃COOH, NH₄OH
366. pH of 0.01 M HCl?
2
367. pH of 0.01 M NaOH?
12
368. Buffer solution resists change in?
pH
369. Example of acidic buffer?
CH₃COOH + CH₃COONa
370. Example of basic buffer?
NH₄OH + NH₄Cl
371. Solubility product constant (Ksp)?
Product of ion concentrations at saturation
372. Common ion effect?
Solubility decreases in presence of common ion
373. Oxidation state of H in H₂O?
+1
374. Oxidation state of O in H₂O?
–2
375. Oxidation state of S
in H₂SO₄?
+6
376. Which gas is known as laughing gas?
Nitrous oxide (N₂O)
377. Which gas is used in welding?
Acetylene (C₂H₂)
378. Which gas is used in balloons?
Helium (He)
379. Which gas is used for sterilization?
Ethylene oxide (C₂H₄O)
380. Which gas is used in refrigeration?
Ammonia (NH₃)
381. Which gas is responsible for ozone layer depletion?
CFCs (Chlorofluorocarbons)
382. Which gas is responsible for global warming?
CO₂
383. Which gas is used in soda water?
CO₂
384. Which gas is used in fire extinguishers?
CO₂
385. Which gas is used in anesthesia?
Nitrous oxide (N₂O)
386. Molecular formula of ozone?
O₃
387. Molecular formula of methane?
CH₄
388. Molecular formula of ammonia?
NH₃
389. Molecular formula of ethane?
C₂H₆
390. Molecular formula of ethylene?
C₂H₄
391. Molecular formula of acetylene?
C₂H₂
392. Molecular formula of benzene?
C₆H₆
393. Molecular formula of glucose?
C₆H₁₂O₆
394. Molecular formula of sucrose?
C₁₂H₂₂O₁₁
395. Molecular formula of ethanol?
C₂H₅OH
396. Molecular formula of acetic acid?
CH₃COOH
397. Which is the simplest alkane?
Methane (CH₄)
398. Which is the simplest alkene?
Ethylene (C₂H₄)
399. Which is the simplest alkyne?
Acetylene (C₂H₂)
400. Functional group of alcohol?
–OH
Part v
401. Functional group of aldehydes?
–CHO
402. Functional group of ketones?
–CO–
403. Functional group of carboxylic acids?
–COOH
404. Functional group of esters?
–COO–
405. Functional group of ethers?
–O–
406. Functional group of amines?
–NH₂
407. Functional group of amides?
–CONH₂
408. Functional group of halides?
–X (X = Cl, Br, I)
409. Alcohol functional group?
–OH
410. Phenol functional group?
–OH attached to aromatic ring
411. Aldehyde example?
Formaldehyde (CH₂O)
412. Ketone example?
Acetone (CH₃COCH₃)
413. Carboxylic acid example?
Acetic acid (CH₃COOH)
414. Ester example?
Ethyl acetate (CH₃COOCH₂CH₃)
415. Ether example?
Diethyl ether (CH₃CH₂OCH₂CH₃)
416. Amine example?
Methylamine (CH₃NH₂)
417. Amide example?
Acetamide (CH₃CONH₂)
418. Halide example?
Chloroethane (C₂H₅Cl)
419. Difference between saturated and unsaturated hydrocarbons?
Saturated: single bonds only; Unsaturated: double/triple bonds
420. Alkane general formula?
CnH2n+2
421. Alkene general formula?
CnH2n
422. Alkyne general formula?
CnH2n–2
423. Benzene formula?
C₆H₆
424. Aromatic compounds contain?
Conjugated π-electron ring (aromatic ring)
425. Example of aromatic compound?
Benzene (C₆H₆)
426. Which gas is released when acids react with carbonates?
Carbon dioxide (CO₂)
427. Which gas is released when metals react with acids?
Hydrogen (H₂)
428. Which gas is released in photosynthesis?
Oxygen (O₂)
429. Which gas is essential for respiration?
Oxygen (O₂)
430. Which gas is responsible for greenhouse effect?
Carbon dioxide (CO₂)
431. Which gas is responsible for acid rain?
Sulfur dioxide (SO₂)
432. Which gas is responsible for ozone layer depletion?
Chlorofluorocarbons (CFCs)
433. Which gas is used in welding?
Acetylene (C₂H₂)
434. Which gas is used in refrigerators?
Ammonia (NH₃)
435. Which gas is used in soda water?
Carbon dioxide (CO₂)
436. Which gas is used in lamps for balloons?
Hydrogen (H₂)
437. Which gas is called laughing gas?
Nitrous oxide (N₂O)
438. Which gas is used as a fuel in rockets?
Hydrogen (H₂)
439. Which gas is used in anesthesia?
Nitrous oxide (N₂O)
440. Which gas is responsible for global warming?
Carbon dioxide (CO₂)
441. Which gas is produced during fermentation?
Carbon dioxide (CO₂)
442. Which gas is used in fire extinguishers?
Carbon dioxide (CO₂)
443. Which gas is used in lamps for helium-neon laser?
Neon (Ne)
444. Which gas is used for sterilization of medical equipment?
Ethylene oxide (C₂H₄O)
445. Which gas is lighter than air?
Hydrogen (H₂)
446. Which gas is heavier than air?
Carbon dioxide (CO₂)
447. Which gas is used in balloons and airships?
Helium (He)
448. Which gas is responsible for smog formation?
Nitrogen dioxide (NO₂)
449. Which gas is used in welding and cutting metals?
Acetylene (C₂H₂)
450. Which gas is used in electric bulbs?
Argon (Ar)
451. What is Avogadro’s number?
6.022 × 10²³
452. Molar mass = ?
Mass of 1 mole of substance (g/mol)
453. 1 mole of gas at STP occupies?
22.4 L
454. Ideal gas equation?
PV = nRT
455. Universal gas constant (R)?
0.0821 L·atm/mol·K or 8.314 J/mol·K
456. Boyle’s law?
P ∝ 1/V (at constant T)
457. Charles’ law?
V ∝ T (at constant P)
458. Avogadro’s law?
V ∝ n (at constant P, T)
459. Dalton’s law of partial pressure?
P_total = P₁ + P₂ + P₃ …
460. Density of gas = ?
d = PM/RT
461. Mole fraction = ?
χ = n_component / n_total
462. Molality (m) = ?
m = moles of solute / kg of solvent
463. Molarity (M) = ?
M = moles of solute / L of solution
464. Normality (N) = ?
N = equivalents of solute / L of solution
465. Equivalence point in titration?
When moles of acid = moles of base
466. End point in titration?
When indicator changes color
467. Primary standard criteria?
Pure, stable, non-hygroscopic, high molar mass
468. Example of primary standard?
Na₂CO₃, KHP, oxalic acid
469. Oxidizing agent gains or loses electrons?
Gains electrons
470. Reducing agent gains or loses electrons?
Loses electrons
471. Redox reaction?
Reaction involving both oxidation and reduction
472. Example of redox reaction?
Zn + CuSO₄ → ZnSO₄ + Cu
473. Electrochemical cell generates?
Electrical energy from chemical energy
474. Anode in galvanic cell?
Site of oxidation
475. Cathode in galvanic cell?
Site of reduction
476. Electrolyte conducts electricity because of?
Presence of ions
477. Strong electrolyte examples?
HCl, NaOH, NaCl
478. Weak electrolyte examples?
CH₃COOH, NH₄OH
479. pH of neutral solution?
7
480. pH of acidic solution?
<7
481. pH of basic solution?
>7
482. Buffer solution resists change in?
pH
483. Example of acidic buffer?
CH₃COOH + CH₃COONa
484. Example of basic buffer?
NH₄OH + NH₄Cl
485. Solubility product constant (Ksp)?
Product of ionic concentrations at saturation
486. Common ion effect?
Decreases solubility in presence of common ion
487. Henry’s law?
Solubility ∝ Pressure
488. Raoult’s law?
Partial vapor pressure ∝ mole fraction
489. Colligative properties depend on?
Number of solute particles
490. Examples of colligative properties?
Vapor pressure lowering, freezing point depression, boiling point elevation, osmotic pressure
491. Osmotic pressure formula?
π = MRT
492. Freezing point depression formula?
ΔTf = Kf·m
493. Boiling point elevation formula?
ΔTb = Kb·m
494. Electrochemical series helps to?
Predict oxidation and reduction
495. Galvanic cell generates?
Electrical energy from chemical energy
496. Electrolytic cell requires?
External electric current
497. Faraday’s first law?
Mass ∝ Charge
498. Faraday’s second law?
Mass ∝ Equivalent weight
499. 1 Faraday = ?
96500 C
500. Valency of hydrogen?
1
Part VI
501. Atomic number (Z) definition?
Number of protons in nucleus
502. Mass number (A) definition?
Number of protons + neutrons
503. Isotopes definition?
Same Z, different A
504. Isobars definition?
Same A, different Z
505. Isotones definition?
Same number of neutrons, different Z
506. Ion definition?
Charged atom or molecule
507. Cation?
Positively charged ion
508. Anion?
Negatively charged ion
509. Electronic configuration of Na?
1s² 2s² 2p⁶ 3s¹
510. Electronic configuration of O?
1s² 2s² 2p⁴
511. Valency definition?
Combining capacity of an element
512. Octet rule?
Atoms tend to have 8 electrons in outer shell
513. Atomic radius trend in periodic table?
Decreases across period, increases down group
514. Ionization energy trend?
Increases across period, decreases down group
515. Electronegativity trend?
Increases across period, decreases down group
516. Electron affinity trend?
Generally increases across period, decreases down group
517. Metallic character trend?
Decreases across period, increases down group
518. Non-metallic character trend?
Increases across period, decreases down group
519. First ionization energy of Hydrogen?
1312 kJ/mol
520. Covalent bond definition?
Sharing of electron pair between atoms
521. Ionic bond definition?
Electrostatic attraction between cation and anion
522. Coordinate bond definition?
Both electrons come from same atom
523. Electronegativity difference in ionic bond?
> 1.7
524. Electronegativity difference in covalent bond?
< 1.7
525. Polar covalent bond?
Unequal sharing of electrons
526. Non-polar covalent bond?
Equal sharing of electrons
527. Electronegativity of Hydrogen?
2.1
528. Electronegativity of Oxygen?
3.5
529. Electronegativity of Fluorine?
4.0
530. Bond length definition?
Distance between nuclei of two bonded atoms
531. Bond energy definition?
Energy required to break one mole of bond
532. Single bond energy example?
H–H = 436 kJ/mol
533. Double bond energy example?
O=O = 498 kJ/mol
534. Triple bond energy example?
N≡N = 945 kJ/mol
535. Bond angle of H₂O?
104.5°
536. Bond angle of CO₂?
180°
537. Bond angle of NH₃?
107°
538. VSEPR theory?
Predicts shape of molecule based on electron pair repulsion
539. Shape of CH₄?
Tetrahedral
540. Shape of NH₃?
Trigonal pyramidal
541. Shape of H₂O?
Bent
542. Shape of CO₂?
Linear
543. Hybridization of CH₄?
sp³
544. Hybridization of NH₃?
sp³
545. Hybridization of H₂O?
sp³
546. Hybridization of CO₂?
sp
547. Dipole moment definition?
Measure of separation of charges in a molecule
548. Dipole moment of CO₂?
0 D (non-polar)
549. Dipole moment of H₂O?
1.85 D (polar)
550. Intermolecular forces types?
London dispersion, Dipole-dipole, Hydrogen bonding
551. Arrhenius acid definition?
Substance that increases H⁺ ions in solution
552. Arrhenius base definition?
Substance that increases OH⁻ ions in solution
553. Bronsted-Lowry acid?
Proton donor
554. Bronsted-Lowry base?
Proton acceptor
555. Lewis acid?
Electron pair acceptor
556. Lewis base?
Electron pair donor
557. Strong acid examples?
HCl, HNO₃, H₂SO₄
558. Weak acid examples?
CH₃COOH, H₂CO₃
559. Strong base examples?
NaOH, KOH
560. Weak base examples?
NH₄OH
561. pH formula?
pH = –log[H⁺]
562. pOH formula?
pOH = –log[OH⁻]
563. Relation between pH and pOH?
pH + pOH = 14
564. Acidic solution pH?
<7
565. Basic solution pH?
>7
566. Neutral solution pH?
7
567. Buffer solution definition?
Resists change in pH
568. Acidic buffer example?
CH₃COOH + CH₃COONa
569. Basic buffer example?
NH₄OH + NH₄Cl
570. Solubility product (Ksp)?
Product of ionic concentrations at saturation
571. Common ion effect?
Decreases solubility of a salt
572. Raoult’s law?
Vapor pressure of solvent ∝ Mole fraction
573. Osmotic pressure formula?
π = MRT
574. Boiling point elevation formula?
ΔTb = Kb·m
575. Freezing point depression formula?
ΔTf = Kf·m
576. Electrolyte definition?
Substance that produces ions in solution and conducts electricity
577. Strong electrolyte examples?
HCl, NaOH, NaCl
578. Weak electrolyte examples?
CH₃COOH, NH₄OH
579. Faraday’s first law of electrolysis?
Mass ∝ Charge
580. Faraday’s second law of electrolysis?
Mass ∝ Equivalent weight × Charge
581. 1 Faraday = ?
96500 C
582. Electrode in electrolysis where oxidation occurs?
Anode
583. Electrode in electrolysis where reduction occurs?
Cathode
584. Electrochemical cell generates?
Electrical energy from chemical energy
585. Electrolytic cell requires?
External current
586. Nernst equation?
E = E⁰ – (0.0591/n) log Q
587. Redox reaction definition?
Reaction involving oxidation and reduction
588. Oxidizing agent gains or loses electrons?
Gains electrons
589. Reducing agent gains or loses electrons?
Loses electrons
590. Corrosion definition?
Gradual destruction of metal by chemical reaction with environment
591. Electroplating purpose?
Prevent corrosion, decorative coating
592.Electrolyte used in electroplating of silver?
AgNO₃
593.Electrolyte used in electroplating of copper?
CuSO₄
594. Electrochemical series helps to predict?
Oxidation and reduction tendencies
595. Conductivity of solution depends on?
Concentration and mobility of ions
596. Primary standard criteria?
Pure, stable, non-hygroscopic, high molar mass
597. Example of primary standard?
Na₂CO₃, KHP, oxalic acid
598. End point in titration?
Indicator changes color
599. Equivalence point in titration?
Moles of acid = Moles of base
600. pH at equivalence point for strong acid–strong base?
7
Part VII
601. Arrhenius definition of acids and bases?
Acid: increases H⁺ in solution; Base: increases OH⁻ in solution
602. Bronsted-Lowry definition of acids and bases?
Acid: proton donor; Base: proton acceptor
603. Lewis definition of acids and bases?
Acid: electron pair acceptor; Base: electron pair donor
604. Strong acid examples?
HCl, HNO₃, H₂SO₄
605. Weak acid examples?
CH₃COOH, H₂CO₃
606. Strong base examples?
NaOH, KOH
607. Weak base examples?
NH₄OH
608. pH formula?
pH = –log[H⁺]
609. pOH formula?
pOH = –log[OH⁻]
610. pH + pOH relation?
pH + pOH = 14
611. Buffer solution definition?
Resists change in pH
612. Acidic buffer example?
CH₃COOH + CH₃COONa
613. Basic buffer example?
NH₄OH + NH₄Cl
614. Solubility product (Ksp) definition?
Product of ionic concentrations at saturation
615. Common ion effect definition?
Decreases solubility of a salt in presence of common ion
616. Raoult’s law definition?
Vapor pressure of solvent ∝ mole fraction
617. Boiling point elevation formula?
ΔTb = Kb·m
618. Freezing point depression formula?
ΔTf = Kf·m
619. Osmotic pressure formula?
π = MRT
620. Electrolyte definition?
Conducts electricity in solution due to ions
621. Strong electrolyte examples?
HCl, NaOH, NaCl
622. Weak electrolyte examples?
CH₃COOH, NH₄OH
623. Faraday’s first law?
Mass ∝ Charge
624. Faraday’s second law?
Mass ∝ Equivalent weight × Charge
625. 1 Faraday = ?
96500 C
626. Electrolysis: anode reaction?
Oxidation occurs at anode
627. Electrolysis: cathode reaction?
Reduction occurs at cathode
628. Electroplating purpose?
Prevent corrosion, decorative coating
629. Electrolyte for silver plating?
AgNO₃
630. Electrolyte for copper plating?
CuSO₄
631. Redox reaction definition?
Reaction involving both oxidation and reduction
632. Oxidizing agent?
Gains electrons
633. Reducing agent?
Loses electrons
634. Corrosion definition?
Gradual destruction of metal by chemical reaction with environment
635. Electrochemical series purpose?
Predict oxidation and reduction tendencies
636. Primary standard criteria?
Pure, stable, non-hygroscopic, high molar mass
637. Examples of primary standards?
Na₂CO₃, KHP, Oxalic acid
638. End point in titration?
Indicator changes color
639. Equivalence point in titration?
Moles of acid = Moles of base
640. pH at equivalence point for strong acid–strong base?
7
641. pH at equivalence point for strong acid–weak base?
<7
642. pH at equivalence point for weak acid–strong base?
>7
643. Conductivity depends on?
Concentration and mobility of ions
644. Molality (m) formula?
m = moles of solute / kg of solvent
645. Molarity (M) formula?
M = moles of solute / L of solution
646. Mol fraction (X) formula?
X = moles of component / total moles
647. Mass percent formula?
(Mass of solute / Mass of solution) × 100
648. Normality (N) formula?
N = Equivalents / L of solution
649. Equivalents formula?
Equivalents = Mass / Equivalent weight
650. Equivalent weight formula?
Molecular weight / n (
number of electrons or H⁺ ions)
651. Electrolysis definition?
Chemical decomposition by electric current
652. Anode in electrolysis?
Positive electrode; oxidation occurs
653. Cathode in electrolysis?
Negative electrode; reduction occurs
654. Electroplating purpose?
Prevent corrosion, decorative coating
655. Electrolyte for silver plating?
AgNO₃
656. Electrolyte for copper plating?
CuSO₄
657. Faraday’s first law?
Mass ∝ Electric charge
658. Faraday’s second law?
Mass ∝ Equivalent weight × Charge
659. 1 Faraday = ?
96500 C
660. Redox reaction definition?
Oxidation + Reduction occurs simultaneously
661. Oxidizing agent?
Gains electrons
662. Reducing agent?
Loses electrons
663. Corrosion definition?
Gradual destruction of metal by chemical reaction
664. Primary standard criteria?
Pure, stable, non-hygroscopic, high molar mass
665. Example of primary standard?
Na₂CO₃, Oxalic acid, KHP
666. End point in titration?
Indicator changes color
667. Equivalence point in titration?
Moles of acid = Moles of base
668. pH at equivalence point (strong acid–strong base)?
7
669. pH at equivalence point (strong acid–weak base)?
<7
670. pH at equivalence point (weak acid–strong base)?
>7
671. Buffer solution definition?
Resists change in pH
672. Acidic buffer example?
CH₃COOH + CH₃COONa
673. Basic buffer example?
NH₄OH + NH₄Cl
674. Solubility product (Ksp) definition?
Product of ionic concentrations at saturation
675. Common ion effect definition?
Decreases solubility of salt in presence of common ion
676. Raoult’s law definition?
Vapor pressure of solvent ∝ Mole fraction of solvent
677. Boiling point elevation formula?
ΔTb = Kb·m
678. Freezing point depression formula?
ΔTf = Kf·m
679. Osmotic pressure formula?
π = MRT
680. Molarity formula?
M = moles of solute / L of solution
681. Molality formula?
m = moles of solute / kg of solvent
682. Mole fraction formula?
X = moles of component / total moles
683. Mass percent formula?
(Mass of solute / Mass of solution) × 100
684. Normality formula?
N = Equivalents / L of solution
685. Equivalent weight formula?
Molecular weight / n (electrons, H⁺, or OH⁻)
686. Electrolyte definition?
Conducts electricity by ion formation
687. Strong electrolyte examples?
HCl, NaOH, NaCl
688. Weak electrolyte examples?
CH₃COOH, NH₄OH
689. Electrolysis: anode reaction?
Oxidation occurs
690. Electrolysis: cathode reaction?
Reduction occurs
691. Electroplating purpose?
Prevent corrosion and decorative coating
692. Electrolyte for silver plating?
AgNO₃
693. Electrolyte for copper plating?
CuSO₄
694. Redox reaction definition?
Oxidation and reduction simultaneously
695. Oxidizing agent?
Gains electrons
696. Reducing agent?
Loses electrons
697. Corrosion definition?
Gradual destruction of metals by chemical reaction
698. Electrochemical series purpose?
Predict oxidation and reduction tendencies
699. Primary standard criteria?
Pure, stable, non-hygroscopic, high molar mass
700. Examples of primary standards?
Na₂CO₃, KHP, Oxalic acid
NEET Quick Revision Chemistry – Key Points & Formulas
Acids & Bases
- Arrhenius: Acid ↑H⁺, Base ↑OH⁻
- Bronsted-Lowry: Acid = proton donor, Base = proton acceptor
- Lewis: Acid = e⁻ acceptor, Base = e⁻ donor
- Strong acids: HCl, HNO₃, H₂SO₄; Strong bases: NaOH, KOH
- pH = –log[H⁺]; pOH = –log[OH⁻]; pH + pOH = 14
- Buffers: Acidic (CH₃COOH + CH₃COONa), Basic (NH₄OH + NH₄Cl)
Solutions & Colligative Properties
- Molarity: M = moles/L
- Molality: m = moles/kg
- Mole fraction: X = moles / total moles
- Normality: N = Equivalents/L
- ΔTb = Kb·m, ΔTf = Kf·m, π = MRT
Electrochemistry
- Electrolytes: Strong (HCl, NaOH), Weak (CH₃COOH)
- Electrolysis: Anode → Oxidation, Cathode → Reduction
- Faraday: 1 F = 96500 C; Mass ∝ Charge; Mass ∝ Eq. weight × Charge
- Electroplating: Ag → AgNO₃, Cu → CuSO₄
Redox & Corrosion
- Oxidizing agent → Gains e⁻; Reducing agent → Loses e⁻
- Corrosion: Gradual metal destruction
- Electrochemical series → Predict redox
Titration
- End point → Indicator color change
- Equivalence point → Moles acid = Moles base
- pH at equivalence: Strong acid–strong base = 7; Strong acid–weak base <7; Weak acid–strong base >