Alcohol, Phenols, and Ethers - Chemistry Most Important MDCAT MCQs With Explanation

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QUESTION: Phenol is known as:
A. Carpolic acid
B. Carbonylic acid
C. Carbolic acid
D. Carbolylic acid
EXPLANATION
The other name for phenol is Carbolic acid.

QUESTION: Phenol is more acidic than alcohols because of the following reason:
A. Delocalization of negative charge in OH group
B. Delocation of positive charge on the carbon atom in ring
C. Delocalization of negative charge in the ring
D. Delocalization of positive charge in the OH group
EXPLANATION
Phenol is more acidic than alcohols due to stabilisation of phenoxide ion through resonance of negative charge in the ring. Presence of electron withdrawing group (COOH,CF3) increases the acidity of phenol by stabilising phenoxide ion while presence of electron releasing group (OH, NH2) decreases the acidity of phenol by destabilising phenoxide ion.

QUESTION: Acetophenone can be formed by which of the following reaction for benzene?
A. Alkylation
B. Acylation
C. Halogenation
D. Nitration
EXPLANATION
Benzene can be converted to acetophenone (methyl phenyl ketone) by Friedel-Crafts acylation. Firstly, we react ethanoyl chloride with aluminum trichloride (AlCl3) to obtain the electrophile CH3C+=O. The electrophile, when provided with the correct conditions, in the presence of benzene, will undergo a substitution reaction to form acetophenone.

QUESTION: Phenol is also called as ____.
A. Carbonic acid
B. Carbolic acid
C. Acetic acid
D. Hydroxy acid
EXPLANATION
Carbonic acid: H2CO3 Acetic acid: CH3COOH (ethanoic acid) Carbolic acid: C6H5OH (phenol) Hydroxy acid: a type of acid found in natural foods

QUESTION: Phenol is a ____ liquid.
A. Dense
B. Hard
C. Deliquescent
D. Intermittent
EXPLANATION
Phenol reacts with moisture in the air to give its smell.

QUESTION: Alcohol having 5% water is called as ________ ?
A. Absolute alcohol
B. Methylated alcohol
C. Rectified spirit
D. Pure spirit
EXPLANATION
Alcohol that is repeatedly purified and then distilled has 5% water in it and it is called rectified spirit.

QUESTION: When a nucleophilic reagent attacks on alcohols, what happens?
A. C - O bond breaks
B. H bond breaks
C. Increase in acidity
D. Dehydration occurs
EXPLANATION
The nucleophile is attracted to the positively charged carbon so the C=O bond breaks and the nucleophile forms a dative bond with the carbon.

QUESTION: Which phenol is most acidic in nature?
A. salicylic acid
B. picric acid
C. cresol
D. O-nitrophenol
EXPLANATION
In picric acid, 3 nitro groups are attached to the phenol, which increases its acidity.

QUESTION: Which of the following is termed as hydroxyl derivative of alkanes?
A. Carboxylic
B. Aldehydes
C. Phenols and ethers
D. Alcohols
EXPLANATION
Alcohols are the hydroxyl derivatives of alkanes in which the –OH group is attached to alkyl group.

QUESTION: Which of the following major product(s) is formed when phenol reacts with sulphuric acid at 100 °C?
A. Ortho-hydroxy benzene sulphonic acid
B. Para-hydroxy benzene sulphonic acid
C. O and p- benzene sulphonic acid
D. Both a and b
EXPLANATION
The image below shows the sulphonation of phenol. Since OH is a ortho para director, both of these form.

QUESTION: In IUPAC naming alcohols are named as ___ ?
A. Alkanal
B. Alkyl alcohols
C. Alkanol
D. Alkenol
EXPLANATION
Alkanols are alcohols and are compounds containing ONLY carbon, hydrogen, and oxygen atoms. Alcohols, which include the alkanols, contain the OH functional group, known as the hydroxy (or hydroxyl) functional group. In the IUPAC system, alcohols are named by changing the ending of the parent alkane name to -ol. Alcohols are classified according to the number of carbon atoms attached to the carbon atom that is attached to the OH group.

QUESTION: The method which is used on an industrial scale for the production of alcohol from alkene?
A. Hydrohalogenation of alkenes
B. Dehydration of alkenes
C. Hydration of alkenes
D. Hydroxylation of alkenes
EXPLANATION
Alkenes can be converted to alcohols by the net addition of water across the double bond.

QUESTION: Ethanol is used as ?
A. a drink
B. a fuel
C. a preservative
D. all of above
EXPLANATION
Ethanol has many uses some which include being a drink, fuel and food preservative.

QUESTION: What is optimum temperature for the process of fermentation?
EXPLANATION
Ethanol is prepared industrially by a process called fermentation which occurs in the presence of certain enzymes and under optimum conditions including optimum temperature which is equal to 25-35°C.

QUESTION: In order to get absolute alcohol the following is added to absorb moisture:
A. MgO
B. CaO
C. CO2
D. Cl2
EXPLANATION
Answer: B Reason: Quicklime (CaO) absorbs water from alcohols, where it opens up its double bonds and connects to two water molecules.

QUESTION: What is the IUPAC name of isopropyl alcohol?
A. 2-propanol
B. 1- propanol
C. 2 - ethanol
D. 2 - propane-1-ot
EXPLANATION
Answer: A Reason: Isopropyl alcohol is another name for 2-propanol.

QUESTION: Which of the following shows maximum boiling point?
A. Primary alcohol
B. Secondary alcohol
C. Tertiary alcohol
D. All of above
EXPLANATION
Answer: A Reason: Primary alcohols have the most exposed OH groups. This means that they are more readily able to form hydrogen bonds. Hydrogen bonds need more energy to be broken and therefore more heat. This results in a higher boiling point.

QUESTION: Which at following can be prepared by the reaction of Grignard reagent with aldehydes?
A. Ketones
B. Hydrocarbons
C. Alcohols
D. Ethers
EXPLANATION
Option C is correct since aldehydes and ketones on reaction with grignard reagent give alcohols (no exceptions), thus all other options are wrong. Reference; http://www.organicchemistrytutorials.com/wp-content/uploads/2019/12/Blog_3_02.jpg

QUESTION: Which of the following is formed when phenol reacts with acetyl chloride?
A. Alcohol
B. Carboxylic acids
C. Esters
D. Amines
EXPLANATION
Option C is correct. Phenol in presence of NaOH reacts with acetyl chloride to form phenyl acetate which is an ester. Phenol can’t form either alcohol or carboxylic acid.

QUESTION: A naphthol has
A. Alcoholic OH
B. -CHO
C. -COOH
D. Phenolic - OH
EXPLANATION
Option D is correct. Reference; https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.researchgate.net%2Ffigure%2FScheme-1-Formation-of-1-naphtol-and-2-hydroxy-1-4-naphtoquinone-byexcitation-of_fig2_331532424&psig=AOvVaw2rJSWDhyC_lej2eDjyrDR&ust=1635693370441000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCIiy7Om28vMCFQAAAAAdAAAAABAD

QUESTION: Tertiary alcohols can change into alkenes by
A. Combustion reaction
B. Oxidation
C. Elimination reaction
D. Addition reaction
EXPLANATION
Option C is correct since treating tertiary alcohol with acidified KMNO4 instead of oxidizing it causes elimination into alkene. Same effect is seen when tertiary alcohol is dehydrated with Hot Alumina or Conc. H2SO4.

QUESTION: Which of the following ions is stable?
A. Ethoxide ion
B. Tertiary alkoxide ion
C. Secondary anion
D. Phenoxide ion
EXPLANATION
Answer: D Reason: Phenoxide ion is relatively stable because of the delocalisation of negative charge due to the resonance in the benzene ring.

QUESTION: The alkenes can be formed by alcohols in the presence of ____.
A. Acidified KMnO4
B. Acidified K2Cr2O7
C. Acidified CuCl2
D. Pyridine
EXPLANATION
Answer: B Reason: Tertiary alcohols are resistant to oxidation. In the presence of acid dichromate (K2Cr2O7) they undergo elimination reactions to give alkenes.

QUESTION: In industries, methanol is prepared from?
A. Marsh gas
B. Carbon dioxide and Water
C. Water gas
D. Methane+H2
EXPLANATION
Option C is correct as water gas is subjected to 200 atm of pressure and passed over a mixture of a heated catalyst consisting of ZnO and Cr2O3 at 40000C to 45000C. This reaction forms gaseous methanol, which is condensed to a liquid.

QUESTION: A substance formed by reduction of phenol with Zn is?
A. Picric acid
B. Benzene
C. Cresol
D. Carbolic acid
EXPLANATION
Option B is correct as Phenol gives out a proton and forms phenoxy anion. This anion later gives out oxygen radical to form a phenyl-free radical. On the other hand, zinc reacts with the oxygen radicals to form Zinc Oxide (ZnO). Finally, hydrogen free radical (formed from hydrogen ion) joins with phenyl-free radical to form Benzene.

QUESTION: Phenol is changed into cyclohexanol by the following method:
A. Hydrogenation
B. Reaction with formaldehyde
C. Nitration
D. Halogenation
EXPLANATION
Option A is correct as Phenol is a benzene ring with an OH group bonded to one carbon, if we hydrogenate the ring, the carbons will use the free valence electrons and bond to hydrogen forming cyclic hexanol.

QUESTION: When C-O bond breaks in alcohol, the most reactive is:
A. Primary alcohol
B. Secondary alcohol
C. Tertiary alcohol
D. Methanol
EXPLANATION
Option C is correct as tertiary alcohols are more reactive because the increased number of alkyl groups increases the positive inductive effect. So, the charge density on the carbon atom increases and hence around the oxygen atom.

QUESTION: Which of the following enzymes present in yeast helps out in fermentation?
A. Diastase
B. Maltase
C. Zymase
D. All of the above
EXPLANATION
Option D The enzymes involved in the fermentation process, present in yeast are Invertase, Zymase, Diastase, Maltase.

QUESTION: Which of the following methods is used to prepare alcohols from alkenes?
A. Reaction of alkenes with X2/water
B. Reaction of alkene with water
C. Reaction of alkene with H2SO4/water
D. Reaction of alkene with Ni
EXPLANATION
Option C Alkenes react with water in the presence of concentrated sulphuric acid to form alcohols CH2=CH2 + H2SO4 —--------> CH3-CH2-O-SO3H CH3-CH2-O-SO3H + H2O —----> CH3-CH2-OH + H2SO4

QUESTION: Rectified spirit is converted into the absolute alcohol by ____.
A. Crystallization
B. Distillation
C. Re-distillation
D. Fractional distillation
EXPLANATION
Option C Alcohol obtained by fermentation is only upto 12%and never exceeds 14%because beyond this limit enzymes become inactive , this alcohol is re-distilled to obtain 95% alcohol which is called rectified spirit.

QUESTION: Aldehydes and ketones can be obtained by the _____.
A. Reduction of alcohol
EXPLANATION
Option B Oxidation of alcohol converts them into aldehydes and ketones. The best reagent for this purpose is acidified potassium dichromate.

QUESTION:  What is optimum temperature for the process of fermentation?
A. 10-15 degrees
B. 25-30 degrees
C. 25-35 degrees
D. 25-40 degrees
EXPLANATION
Option C is correct since 25-35 degrees is the perfect range for the process of fermentation. 32-35 degrees Celsius is the ideal temperature range. Option A is incorrect since 10-15 degrees celsius is too low for the process of fermentation. Option B is incorrect since 25-30 degrees celsius is not the ideal range. Since the optimum temperature for fermentation is between 32-35 degrees celsius. Option D is incorrect since 25-40 degrees celsius is too high for the process of fermentation. Every degree above this range (32-35) depresses fermentation.

QUESTION: When O-H bond breaks in alcohol, the order of reactivity is
A. Primary alcohol ) secondary alcohol ) tertiary alcohol
B. Methyl alcohol ) primary alcohol ) secondary alcohol ) tertiary alcohol
C. Primary alcohol ( secondary alcohol ( tertiary alcohol
D. Ethanol ) primary alcohol ) secondary alcohol ) tertiary alcohol
EXPLANATION
Option B is correct since the order of reactivity of alcohols when the O-H bond breaks are methyl alcohol(greatest degree of cleavage) --- primary alcohol---secondary alcohol and tertiary alcohol (lowest degree of cleavage) due to the greater electron-donating effect of three alkyl groups rather than one. Option A is incorrect since it does not talk about the methyl alcohol. Option C is incorrect since it states the order of reactivity in the reverse order. Option D is incorrect since it mentions ethanol which can be included in primary alcohol rather than methanol.

QUESTION: Glycerol can also be termed as
A. 1- butanol
B. 1, 2, 3 - propanetriol
C. 2 - methyl - propanol
D. ISObutyl alcohol
EXPLANATION
Glycerol can also be termed as 1,2,3,propanetriol.Glycerol is a trihydroxy sugar alcohol with three carbon atoms and three hydroxyl groups. The presence of multiple hydroxyl groups and carbon atoms makes it an organic polyol compound.

QUESTION: Which of the following alcohol give iodoform test?
A. Propanol
B. Methanol
C. Ethanol
D. Butanol
EXPLANATION
Ethanol shows positive result with iodoform test. Ethanol has a hydrogen atom attached to the carbon with the -OH group. Yellow precipitates are observed after the reaction.

QUESTION: A polymer called Bakelite is formed by the reaction of phenol with:
A. Hydrogen
B. Ethers
C. Carboxylic acid
D. Formaldehyde
EXPLANATION
The reaction is condensation polymerisation. In the case of bakelite, phenol and formaldehyde condense to form the monomer giving out H2O as by product.

QUESTION: Which organic compound will form yellow crystals during iodoform test?
A. Phenols
B. Acetone
C. Ethanol
D. Methanol
EXPLANATION
Option C is correct since Ethanol is the only primary alcohol that gives a positive iodoform test. All other options do not give yellow precipitate during the iodoform test.

QUESTION: Which of following is trihydric alcohol
A. Glycol and cyclohexanol
B. glycerol
C. ethylene glycol
D. resorcinol
EXPLANATION
This option is correct because trihydric is the compound having three hydroxyl groups (OH). Thus glycerol is having three OH groups. Option A is incorrect because glycol is not trihydric but dihydric alcohol while cyclohexanol is having one OH group. Option C is also incorrect because ethylene glycol is not trihydric but a dihydric alcohol. Option D is also incorrect because resorcinol is a meta isomer of benzenediol with a formula of C6H4(OH)2.It is not a trihydric alcohol.

QUESTION: Alcohol is dehydrated by the following reaction
A. elimination reaction
B. oxidation reaction
C. combustion
D. decomposition
EXPLANATION
This option is correct because alcohol when heated with strong acid ( H2SO4, H3PO4) undergoes elimination reaction to generate alkene and water. This process is known as dehydration since water molecules are removed. Option B is incorrect since when alcohol is oxidized they form carbonyl compound. In this process dehydration does not occur. Option C is incorrect because combustion is also a type of oxidation in which energy is released with CO2.In this process dehydration may occur but in certain conditions. Option D is incorrect because during decomposition dehydration doesnt occur. In this process a single compound is broken down into more than one entity.

QUESTION: Ethanol obtained by the process of fermentation never exceeds to _________?
A. 0.12
B. 0.14
C. 0.2
D. 0.32
EXPLANATION
(In fermentation the ethanol obtained never exceeds more than 0.14)

QUESTION: When O-H bond breaks in alcohol is the order of reactivity
A. Primary alcohol ) secondary alcohol ) tertiary alcohol
B. methyl alcohol ) primary alcohol ) secondary alcohol ) tertiary alcohol
C. Primary alcohol ( secondary alcohol ( tertiary alcohol
D. ethanol ) primary alcohol ) secondary alcohol ) tertiary alcohol
EXPLANATION
This option is correct because it shows the correct order of reactivity of alcohol when O-H bond break. According to this methyl alcohol are more reactive because when O-H bond breaks down methoxide (alkoxide ) is formed. This methoxide is very unstable and immediately gains stability. Thus in this order tertiary alcohol are the most stable. Methyl alcohol>primary alcohol>secondary alcohol> tertiary alcohol.

QUESTION: The solution of phenol in water has a pH of about?
A. 4-5
B. 3-5
C. 2-4
D. 5-6
EXPLANATION
Option D is correct because: The pH of a typical dilute solution of phenol in water is around 5 - 6. Options A,B,C are incorrect because: Wrong pH.

QUESTION: Alcohol is dehydrated by the following reaction:
A. Elimination reaction
B. Oxidation reaction
C. Combustion
D. Decomposition
EXPLANATION
Option A is correct because: Tertiary alcohols in the presence of acid dichromate undergo elimination reactions to give alkenes. They get dehydrated to form alkenes. Option B is incorrect because: Oxidation of alcohols convert them into aldehydes and ketones. Option C is incorrect because: Complete combustion of alcohols produces carbon dioxide gas and water vapour. Option D is incorrect because: Most alcohol is broken down, or metabolised, by an enzyme in your liver cells known as alcohol dehydrogenase (ADH). ADH breaks down alcohol into acetaldehyde, and then another enzyme, aldehyde dehydrogenase (ALDH), rapidly breaks down acetaldehyde into acetate.

QUESTION: The organic compounds having close resemblance in structure as well as properties are:
A. Glycol and cyclohexanol
B. Formaldehyde and benzol
C. Diethyl ether and ethyl alcohol
D. Methanal and acetone
EXPLANATION
Option A is correct since glycol and cyclohexanol both bear the OH group and are similar in structure and properties. Option B is incorrect since formaldehyde is a methanol whereas benzol is an impure benzene. Option C is incorrect since diethyl is an ether and ethyl alcohol is an alcohol, they also differ in properties. Option D is incorrect since methanol refers to ethanol, which is poisonous to drink and acetone is the simplest ketone.

QUESTION: Phenols react with calcium carbonate and produce _________.
A. H2 gas
B. CO2 gas
C. O2
D. None of these options are correct
EXPLANATION
Option D is correct since none of the given options are correct. Options A, B, and C are incorrect since it does not evolve H2, CO2 or O2 gas.

QUESTION: Phenol was obtained for the first time from?
A. Coke
B. Pitch
C. Aromatic compounds
D. Coal tar
EXPLANATION
Option D is correct since phenol was first obtained from coal tar by Friedlieb Ferdinand Runge. Options A, B, and D are incorrect since phenol was not obtained from coke, pitch, or aromatic compounds.

QUESTION: Which of following is an example of electrophilic attack on alcohol?
A. C2H5OH + CH3COOH H2SI4
B. 2C2H50H + 2Na ____2CH50Na + H2
C. C2S5OH + HCl ZnClL2 C2H5CL+ H20
D. Both Options A and B are correct
EXPLANATION
Option D is correct since both Option A and B show electrophilic attack on alcohols. Option A is incorrect since not only this option shows electrophilic attack on alcohols. Option B is incorrect since not only this option shows electrophilic attack on alcohols. Option C is incorrect since the reaction is not an electrophilic attack on alcohols.

QUESTION: What is optimum temperature for the process of fermentation?
A. 10-15 degrees
B. 25-30 degrees
C. 25-35 degrees
D. 25-40 degrees
EXPLANATION
Ethanol is prepared industrially by a process called fermentation which occurs in the presence of certain enzymes and under optimum conditions including optimum temperature which is equal to 25-35°C.

QUESTION: Which of the following catalysts is used in the industrial preparation of methanol?
A. Zinc oxide and alumina
B. Alumina and silica
C. Silica and Chromium oxide
D. Zinc oxide and Chromium oxide
EXPLANATION
For the industrial preparation of methanol, zinc oxide and chromium oxide is used as a catalyst. CO + 2H2 >>>>ZnO + Cr2O3 + 450°C + 200atm>>>>>>>>>>> CH3OH

QUESTION: Organic compounds that are considered as derivatives of water are:
A. Aldehydes & Ketones
B. Alcohols and Phenols
C. Phenols and Ethers
D. Carboxylic acids
EXPLANATION
Alcohols, phenols, and ethers are much closer to water in structure and hence are considered as derivatives of water.

QUESTION: A substance formed by reduction of phenol with Zn is:
A. Picric acid
B. Benzene
C. Cresol
D. Carbolic acid
EXPLANATION
When phenol reacts with zinc in the presence of heat, phenol reduces to zinc. C6H6O +Zn → C6H6 + ZnO

QUESTION: What is the IUPAC name of isopropyl alcohol?
A. 2 - propanol
B. 1 - propanol
C. 2 - ethanol
D. 2 - propane-1-ot
EXPLANATION
The structure of isopropyl alcohol is CH3-CH(OH)-CH3. Its IUPAC name is 2-propanol.

QUESTION: Iso-Butyl alcohol has following carbon attached to hydroxyl group:
A. Tertiary
B. Secondary
C. Quaternary
D. Primary
EXPLANATION
Primary carbon is that carbon atom that is bonded to only one carbon atom. Secondary carbon is bonded to two carbon atoms. Tertiary carbon is bonded to three carbon atoms while Quaternary carbon is bound to four carbon atoms. Isobutyl alcohol, 2-Methyl-1-propanol, or isobutanol, is a three-carbon chain, with the OH group at the primary, end carbon, and a methyl group on the middle carbon.

QUESTION: Oxidation of alcohol gives:
A. Amines
B. Alkane
C. Aldehyde
D. Alkynes
EXPLANATION
Oxidation of alcohol results in the formation of aldehydes. R-OH gets converted to R-CHO after oxidation.

QUESTION: We can prepare alcohol using an ether. What is typically the reagent used for ether to break down to alcohol?
A. NaBH4
B. HBr
C. Na2Cr2O7
D. Grignard reagent
EXPLANATION
An ether can be broken down into alcohols if the reagent is strong enough to break the bond of the O atom. A strong acid such as HBr can break it to form an alcohol and an alkyl halide but the ratio should be 1:1. If there’s an excess HBr, it will form two alkyl halides and not an alcohol.

QUESTION: Which of the following is the correct order of increasing boiling point?
A. Methanol > Ethanol
B. Methanol < Ethanol
C. Methanol = Ethanol
D. None of these
EXPLANATION
The correct option is B. Boiling point increases as the molecular mass increases. So, ethanol have the greater molecular mass than methanol. So it has greater boiling point.

QUESTION: We can prepare alcohol using an ether. What is typically the reagent used for ether to break down to alcohol?
A. NaBH4
B. HBr
C. Na2Cr2O7
D. Grignard reagent
EXPLANATION
An ether can be broken down into alcohols if the reagent is strong enough to break the bond of the O atom. A strong acid such as HBr can break it to form an alcohol and an alkyl halide but the ratio should be 1:1. If there’s an excess HBr, it will form two alkyl halides and not an alcohol.

QUESTION: Which of the following is the correct order of increasing boiling point?
A. Methanol > Ethanol
B. Methanol < Ethanol
C. Methanol = Ethanol
D. None of these
EXPLANATION
The correct option is B. Boiling point increases as the molecular mass increases. So, ethanol have the greater molecular mass than methanol. So it has greater boiling point.

QUESTION: Oxidation of primary alcohol gives:
A. Ketone
B. Aldehyde
C. Ester
D. Amide
EXPLANATION
Oxidation of primary alcohol leads to the formation of aldehyde.

QUESTION: 3 Moles of ethanol react with 1 mole of PBr3 to form 3 moles of bromoethane and 1 mole of X. Which of the following is X?
A. H3PO4
B. H3PO2
C. HPO3
D. H3PO3
EXPLANATION
The reaction equation for the reaction of ethanol is given below according to it,the answer is H3PO3.  3C2H5OH+PBr3→3C2H5Br+H3PO3

QUESTION: The conversion of phenol to benzene in the presence of zinc involves:
A. Oxidation
B. Reduction
C. Dehydroxylation
D. Dehydrogenation
EXPLANATION
Benzene can be prepared from phenols too through their reduction. In this process vapours of phenol are passed over heated zinc dust. Zinc dust reduces them to form benzene.

QUESTION: Which one of the following pairs of substances react together forming an organic product that gives a neutral solution in water?
A. CH3 CO2 H and NaOH
B. C6H5OH and Na
C. C6H5NH2 and HCl
D. CH3CO2H and PCl5
E. CH3COCH3 and LiAlH4
EXPLANATION
Option E is correct because it leads to a reduction reaction of a ketone which forms a secondary alcohol which is a neutral substance.

QUESTION: A solid compound dissolves readily in water to give a weakly alkaline solution. On evaporation of the water, X was recovered unchanged. Which one of the following could be X?
A. CH3 NH3 Cl
B. CH3 O- Na+
C. C6H5 O-Na+
D. C6H5NH2
E. H2NCH2CO2H
EXPLANATION
Sodium phenoxide is a moderately strong base giving an alkaline solution upon dissolution in water.And on evaporation of water it can be recovered fully.

QUESTION: In t-butyl alcohol, the tertiary carbon is bonded to:
A. No H-atoms
B. One H-atoms
C. Three H-atoms
D. Four C-atoms
EXPLANATION
Tertiary alcohol has the hydroxyl group on a tertiary (3°) carbon atom, which is bonded to three other carbons.  A primary alcohol has the hydroxyl group on a tertiary (1°) carbon atom, which is bonded to one other carbon. Secondary alcohol has the hydroxyl group on a secondary (2°) carbon atom, which is bonded to two other carbons.

QUESTION: The question attached below belongs to the topic of phenols:
A. Resorcinol
B. Aspirin
C. Picric acid
D. Mesitol
EXPLANATION
The structure shown above is of Picric acid.

QUESTION: Which one of the following is NOT a meta directing group?
A. COOH
B. SO3H
C. CHO
D. OH
EXPLANATION
OH is not a meta directing group rather a ortho-para directing group.

QUESTION: Which one of the following does NOT give an iodoform test?
A. CH3OH
B. CHCH2OH
C. CH3CHO
D.  CHiCOCH3
EXPLANATION
Methyl alcohol CH3−OH does not form Iodoform as methyl alcohol cannot be oxidised to a compound containing methyl keto group as methyl alcohol has only one C atom.

QUESTION: Which of the following would be the best solvent for an SN2 reaction?
A. H2O
B. CH3CH2OH
C. CH3SOCH3
D. CH3CH2CH2CH2CH2CH3
EXPLANATION
Polar aprotic solvents are the best SN2 mechanism. Polar aprotic implies solvents that are polar but don’t give off protons in solutions, this perfectly fits option C. Option D is wrong because this hydrocarbon is not polar. Option B is wrong because it is protic same goes for H2O, which is also polar.

QUESTION: Which of the following would be the best solvent for an SN2 reaction?
A. H2O
B. CH3CH2OH
C. CH3SOCH3
D. CH3CH2CH2CH2CH2CH3
EXPLANATION
Polar aprotic solvents are the best SN2 mechanism. Polar aprotic implies solvents that are polar but don’t give off protons in solutions, this perfectly fits option C. Option D is wrong because this hydrocarbon is not polar. Option B is wrong because it is protic same goes for H2O, which is also polar.

QUESTION: The reaction between fat and NaOH called:
A. Esterification
B. Hydrogenolysis
C. Hydrogenation
D. Saponification
EXPLANATION
Saponification is a process that involves the conversion of fat, oil, or lipid, into soap and alcohol by the action of heat in the presence of aqueous alkali (e.g. NaOH).

QUESTION: Which structures show a primary alcohol that cannot be dehydrated to form an alkene?  CH3OH  CH3CH2OH  CH3CH(OH)CH3
A. Only I
B. Only I and II
C. Only II and III
D. Only I and III
EXPLANATION
For alkene, we need to have a double bond between two carbon atoms.CH3OH has only one carbon atom, so even if it is dehydrated it can not form an alkene. Hence it is our answer.

QUESTION: Phenol reacts with concentrated nitric acid to form?
A. O nitrophenol
B. 2,4,6-trinitrophenol
C. Does not react with concentrated nitric acid
D. Both a and b
EXPLANATION
With concentrated nitric acid, phenol is converted to 2,4,6-trinitrophenol. The product is commonly known as picric acid. The yield of the reaction product is poor. Nowadays picric acid is prepared by treating phenol first with concentrated sulphuric acid which converts it to phenol-2,4-disulphonic acid, and then with concentrated nitric acid to get 2,4,6-trinitrophenol.

QUESTION: Ethyl alcohol when treated with excess concentrated H2SO4 may give:
A. Only diethyl sulphate
B. Only diethyl ether
C. Ethene
D. All of the above
EXPLANATION
When excess ethanol is heated with sulphuric acid, we get Diethyl ether.

QUESTION: IUPAC name of the given compound is:
A. 1,4-Dimethyl hexanol
B. 2,4-Diethyl hexanol
C. 4,5-Dimethyl hexanol
D. 4-methyl,5 ethyl hexanol
E. 2,4-Dimethyl hexanol
EXPLANATION
The main chain of organic compound contains six carbon atoms as shown below:  Methyl group is present on 2nd carbon and 4th carbon. So the IUPAC name is 2,4-Dimethylhexanol. Hence the answer is E.

QUESTION: The question below belongs to the topic of Benzene:
A. meta-directing and deactivating group
B. ortho-para directing and deactivating group
C. ortho-para directing and deactivating group
D. ortho-directing and activating only
E. para-directing and deactivating only
EXPLANATION
NH2 is an ortho-para directing group which is an activating group.

QUESTION: The structural formula of picric acid is:
A. Option A
B. Option B.
C. Option C
D. Option D
E. Option E
EXPLANATION
This structure is just a factual recall:

QUESTION: For halogenation of benzene, which reagent is used:
A. H2SO4
B. AlCl3
C. HNO3
D. HCl
EXPLANATION
Benzene reacts with AlCl3 and Cl2 to form chlorobenzene. The catalyst AlCl3 is regenerated at the end of the reaction

QUESTION: The acidity of Phenol is due to its _______:
A. Nature of Benzene
B. Double bond in benzene ring
C. Nature of phenoxide
D. Hyoxal group
EXPLANATION
Phenoxide ion is a stable anion, it forms a weak conjugate base and therefore a stronger acid

QUESTION:  Which one of the following is the proper classification of formula given below:
A. Primary
B. Secondary
C. Tertiary
D. Polyhydride
EXPLANATION
Explanation will be added soon.

QUESTION: Which one of the following is an appropriate structure of product of bromination?
A. Option A
B. Option B
C. Option C
D. Option D
EXPLANATION
C, since it is an ortho para directing group.

QUESTION:  Which one of the following is an appropriate name of the compound given below?
A. 1,3,6-Trinitrophenol
B. m-Nitrophenol
C. Tartaric acid
D. Picric acid
EXPLANATION
A is the correct structural identification.

QUESTION: It is the general formula of:
A. 2, 4-Dinitrophenyl hydrazine
B. 1, 3-Dinitrophenyl hydrazone
C. Phenyl hydrazone
D. 2, 4-Dinitrophenyl hydrazone
EXPLANATION
Correct structural identification

QUESTION: Which one of the following is NOT able to denature the ethanol?
A. Methanol
B. Lactic acid
C. Pyridine
D. Acetone
EXPLANATION
Methanol, pyridine and acetone are able to denature ethanol.

QUESTION: How will you distinguish between methanol and ethanol?
A. By Lucas test
B. By silver mirror test
C. By oxidation
D. By Iodoform test
EXPLANATION
The solution in the ethanol test tube should go cloudy and then a yellow precipitate of tri-iodomethane (iodoform) should be seen. Methanol won’t react.

QUESTION: To produce absolute alcohol (100%) from rectified spirit (95.6% alcohol), the remaining 4.4% water must be removed by a drying agent such as
A. Calcium oxide
B. Calcium chloride
C. Calcium carbonate
D. Carbon monoxide
EXPLANATION
if we add lime (CaO) to the rectified spirit then the water of the mixture can be absorbed by the lime. As a result, the percentage of ethanol will be changed. So the mixture will not act as an azeotropic mixture. In this way, we can prepare absolute alcohol by using the distillation method from a rectified spirit.

QUESTION: Primary, secondary and tertiary alcohols can be identified and distinguished by
A. Lucas test
B. Iodoform test
C. Baeyer’s test
D. Silver mirror test
EXPLANATION
The Lucas test differentiates between primary, secondary, and tertiary alcohols. It works because secondary carbocations are more stable and form faster than primary carbocations, and tertiary carbocations are so stable that the reaction takes place almost immediately

QUESTION: Which one of the following alcohol is indicated by formation of yellow crystals in the Iodoform test?
A. MethanoL
B. Ethanol
C. Butanol
D. Propanol
EXPLANATION
Ethanol is the only primary alcohol to give the triiodomethane (iodoform) reaction. If R is a hydrocarbon group, then you have secondary alcohol. Lots of secondary alcohols give this reaction, but those that do all have a methyl group attached to the carbon with the -OH group. All other alcohols do not have -OH group attached to carbon attached to a methyl group

QUESTION: The formula of 2, 4, 6-tribromo phenol is
A. A
B. B
C. C
D. D
EXPLANATION
Carbons are numbered according to the placement of -OH group. The carbon to which the OH group is attached is C1. The bromines must be attached to C2, C4 and C6 on the benzene going in a clockwise direction from C1.

QUESTION: Which one of the following groups is indicated when HCl is formed by reaction of ethanol with phosphorus pentachloride
A. Amino group
B. Hydroxyl group
C. Halide group
D. Hydride group
EXPLANATION
When a -OH group(hydroxyl group) containing organic compound is reacted with with phosphorus pentachloride, it forms HCl an halogen by the reaction equation shown below:

QUESTION: In the following reaction, what product(s) may be formed? C2H5OH + PCl5 → ?
A. C2H5Cl only
B. C2H5Cl and HCl
C. C2H5Cl, POCl3 and HCl
D. C2H5Cl and POCl3
EXPLANATION
The following reaction occurs.

QUESTION: Aqueous phenol decolorizes bromine water to form a white precipitate. What is the structure of the white precipitate formed?
A. A
B. B
C. C
D. D
EXPLANATION
The following reaction occurs.

QUESTION: ,
A. A
B. B
C. C
D. D
EXPLANATION
Oxidation of phenyl ethanol gives acetophenone.  Please note that the oxidation of primary alcohols gives aldehydes, while the oxidation of secondary alcohols gives ketones. Tertiary alcohols cannot be oxidised at all.

QUESTION: The alkaline hydrolysis of bromoethane shown below gives alcohol as the product H3C―CH3―Br → H3C―CH2―OH. The reagent and the condition used in this reaction may be:
A. H2O at room temperature
B. Ethanol, heat
C. KOH in alcohol
D. Dilute NaOH(aq) warm
EXPLANATION
It is a nucleophilic substitution reaction in which the Br-ion is replaced by the OH- from NaOH.

QUESTION: . The dehydration of ethyl alcohol with concentrated H2SO4 at 140°C gives:
A. Ethene
B. Diethyl ether
C. Alcohol
D. Carboxylic acid
EXPLANATION
At 140°C in the presence of sulfuric acid two molecules of ethanol are dehydrated (lose a molecule of water) to form ether.

QUESTION: Ethanol can be converted in to ethanoic acid by:
A. Oxidation
B. Fermentation
C.  Hydration
D. Hydrogenation
EXPLANATION
The ethanol will first oxidize into acetaldehyde, which can be identified by its sweet smell. This reaction will also produce water. The mixture is then left to oxidize further. When oxidation is complete, acetaldehyde will convert into ethanoic acid which has a comparatively sharper smell – like vinegar.

QUESTION: The following structure is of a:
A. Secondary alcohol
B. Primary alcohol
C. Tertiary alcohol
D. Carboxylic acid
EXPLANATION
A secondary alcohol has the hydroxyl group on a secondary (2°) carbon atom, which is bonded to two other carbon atoms.

QUESTION: When ethanol is warmed with ethanoic acid in the presence of a strong acid catalyst, an ester ethyl ethanoate is formed.  CH3CH2OH + CH3CO2H → CH3CO2CH2CH3  During this reaction:
A. Alcohol is reduced
B. O-H bond in ethanoic acid is broken
C. O-H bond in ethanol is broken
D. Acid is oxidised
EXPLANATION
Ester hydrolysis is a reaction that breaks an ester bond with a molecule of water or a hydroxide ion to form a carboxylic acid and an alcohol.

QUESTION: Primary alcohols usually give us aldehydes when oxidized in the presence of Na2Cr3O7, what will the product be, when the secondary alcohols are oxidized in the same conditions?
A. Alkenes
B. Alkynes
C. Alkyl halides
D. Ketones
EXPLANATION
Secondary alcohols are oxidized to ketones - and thats it. For example, if you heat the secondary alcohol propan-2-ol with sodium or potassium dichromate(VI) solution acidified with dilute sulphuric acid, propanone is formed.

QUESTION: When CH3-CH2-OH is oxidized in the presence of K2Cr2O7 and H2SO4, the product formed is:
A. A
B. B
C. C
D. D
EXPLANATION
Aldehyde, when undergoes an oxidation reaction in the presence of acidified potassium dichromate or alkaline potassium permanganate, forms carboxylic acid as a product.

QUESTION: Which of the following is a secondary alcohol?
A. Option A
B. Option B
C. Option C
D. Option D
EXPLANATION
Carbon atom that carries the -OH group is attached to two alkyl groups

QUESTION: Which enzyme is involved in the fermentation of glucose:
A. Zymase
B. Invertase
C. Urease
D. Diastase
EXPLANATION
Zymase is the enzyme that catalyses the fermentation of sugar into ethanol and carbon dioxide.

QUESTION: Tertiary alcohols are not oxidized into carbon compounds because
A. They contain more alkyl group
B. They have no alpha-hydrogen
C. Suitable oxidizing agent is not available
D. None of the above
EXPLANATION
Tertiary alcohols (R3COH) are resistant to oxidation because the carbon atom that carries the OH group does not have a hydrogen atom attached but is instead bonded to other carbon atoms.

QUESTION: Which compound shows the highest boiling point
A. CH3COOH
B. C2 H5 OH
C. C2 H2-0 C2 H5
D. (CH3CH2)3N
EXPLANATION
(CH3CH2)3N has the highest boiling point.

QUESTION: The alcohol given 𝐶𝐻3 − 𝐶𝐻2 − 𝐶(𝐶𝐻3)2 −𝑂𝐻. If oxidized with a strong oxidizing agent given:
A. Aldehyde
B. Ketone
C. Ether
D. None of the above
EXPLANATION
As it is a primary alcohol so will give an aldehyde on oxidation (alcohol is on the terminal carbon)

QUESTION: Four beakers containing ethanol, ethanol, propanone and phenol separately. Aqueous bromine was added to each beaker. A white ppt was produced in one beaker. This beaker contains.
A. Ethanol
B. Phenol
C. Ethanal
D. Propanone
EXPLANATION
If bromine water is added to a solution of phenol in water, the bromine water/aqueous bromine is decolarized and a white precipitate is formed which smells of antiseptic. The precipitate is 2,4,6- tribromophenol.