Free Benzene and Aromatic Compounds MCQs with Answers
172 Benzene and Aromatic Compounds MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Benzene has a planar ring of delocalised π electrons, giving aromatic stability and equal carbon-carbon bond lengths. The topic covers resonance, electrophilic substitution reactions such as nitration, halogenation, sulphonation and Friedel-Crafts reactions, along with substituent effects and the distinction between substitution in benzene and addition in ordinary alkenes.
Last updated
172 questions · page 8 of 9
- A. Acetyl chloride
- B. Acetic acid
- C. Ethyl benzene
- D. Ethanoic acid
Explanation: The benzene reacts with acetyl chloride in presence of anhydrous aluminum chloride to form acetophenone.
Correct answer: Acetyl chloride- A. Nitration
- B. Ammonolysis
- C. Sulphonation
- D. Reduction of benzene
Explanation: Nitration reactions are the addition of a nitro group into an organic compound.
Correct answer: Nitration- A. Acylation
- B. Carbonyl reduction
- C. Alkylation
- D. Formylation
Explanation: The introduction of an RC(O)+ group (also called an acyl group) in benzene is called acylation.
Correct answer: Acylation- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: We are asked to describe the possible product of bromination. From the question, we can possibly conclude that the OH group is already…
Correct answer: Option C- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: This set of reaction is known as Friedal Craft Acylation and in this, CH3CH3COCl i.e propanoyl chloride reacts with benzene and the…
Correct answer: Option D- A. ii, iii, iv
- B. ii, iii
- C. i, iv
- D. i, ii, iv
Explanation: The 3 5 directing groups or Meta directing groups are as follows:Aldehyde (-CHO), Ketone (-CO-), Ester (-RCOOR'), Carboxyl Group (-COOH)…
Correct answer: ii, iii- A. CH3CO+
- B. AlCl3
- C. CH3+
- D. CH3COCl
Explanation: CH3COCl reacts with AlCl3 to form ----> AlCl4- and CH3CO+CH3CO+ has a positive charge thus it is an electrophile and attracted to…
Correct answer: CH3CO+- A. Electrophilic addition
- B. Electrophilic substitution
- C. Nucleophilic substitution
- D. Nucleophilic addition
Explanation: Benzene has an extended delocalised pi system above and below the ring which makes it highly attracted to electron-deficient species…
Correct answer: Electrophilic substitution- A. Br+
- B. FeCl4+
- C. Fe2+
- D. Fe3+
Explanation: Benzene reacts with bromine in an electrophilic substitution reaction, but only in the presence of a catalyst to yield bromobenzene.
Correct answer: Br+- A. Benzoic acid
- B. Methyl benzene
- C. Benzaldehyde
- D. Nitrobenzene
Explanation: Activating groups increase the reactivity of electrophilic substitutions, whereas deactivating groups decrease it.Activating groups are…
Correct answer: Methyl benzene- A. m-directing
- B. o-directing
- C. o -& p -directing & deactivating
- D. o -& p -directing & activating
Explanation: Chlorine has a lone pair, so it can donate electrons to the benzene ring.
Correct answer: o -& p -directing & deactivating- A. C2H5
- B. SO3H
- C. NH2
- D. CH3
Explanation: order of activating group (NH2, NHR, NHCOCH3, OCH3,CH3,C2H5(and deactivating group (NO2, CN, CHO, COR, COOH, COOR, SO3H)to increase and…
Correct answer: SO3H- A. A cyclic compounds
- B. Ali cyclic compounds
- C. Hetro cyclic compounds
- D. Aromatic compounds
Explanation: Aromatic compounds are a class of cyclic organic compounds that contain one or more rings with a special stability due to the…
Correct answer: Aromatic compounds- A. R
- B. OH
- C. COR
- D. NH2
Explanation: The acyl group (COR) is not ortho para directing and activating. It is a deactivating group due to the presence of the carbonyl group…
Correct answer: COR- A. -OH
- B. -OR
- C. -NH2
- D. -CN
Explanation: -CN (Cyano group) is a deactivating group. It withdraws electron density from the ring through the inductive effect, reducing the…
Correct answer: -CN- A. of its cyclic nature
- B. of having three double bonds
- C. of aromatic character
- D. of delocalization of electrons
Explanation: The correct answer is that benzene undergoes substitution reactions more easily due to the delocalization of electrons.
Correct answer: of delocalization of electrons- A. An aromatic compound cannot be completely converted into CO2 and other products during burning
- B. The available amount of oxygen present in the air is not sufficient to completely burn the available compound
- C. Aromatic compounds produce compounds on burning that are of black color
- D. None of the above
Explanation: Aromatic compounds produce a smoky flame when burned due to their high carbon content.
Correct answer: The available amount of oxygen present in the air is not sufficient to completely burn the available compound- A. slower rate
- B. faster rate
- C. same rate
- D. depends on the conditions
Explanation: Compared to benzene, nitration of toluene occurs at a faster rate due to the presence of the methyl group (-CH3), which is an…
Correct answer: faster rate- A. PVC
- B. Benzene
- C. Toluene
- D. Teflon
Explanation: Benzene is formed by the cyclic trimerization of three ethyne (acetylene) molecules in a chemical process that rearranges the atoms into a…
Correct answer: Benzene- A. They have ring structure of carbon atoms.
- B. They have a relatively high percentage of hydrogen atoms.
- C. They have a relatively high percentage of carbon atoms.
- D. They resist reactions with air/oxygen.
Explanation: The aromatic compound displays aromaticity. They burn with a strong sooty yellow flame.
Correct answer: They have a relatively high percentage of carbon atoms.