MCQGeeks
0 : 0 : 1
CBSE
JEE
NTSE
NEET
English
UK Quiz
Quiz
Driving Test
Practice
Games
NEET
NEET Chemistry MCQ
Aldehydes, Ketones Mcq Neet Chemistry
Quiz 6
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Q.1
on Q151) Which of the following compounds containing carbonyl group will give coloured crystalline compound with
0%
a) CH3COCNH2
0%
b) CH3COCH3
0%
c) CH3COCl
0%
d) CH3COOC2H5
Explanation
Only aldehyde and ketones react with 2,4-dinitrophenyl hydrazine (DNP) to produce characteristic red or orange colour solution Answer : (b)
Q.2
Which statement is incorrect in the case of acetaldehyde and acetone?
0%
a) Both reduce ammonical silver nitrate to silver
0%
b) Both react with hydrazine to form hydrazones
0%
c) Both react with hydroxylamine to form oximes
0%
d) Both react with sodium bisulphite to form addition product
Explanation
Only aldehydes reduce Tollens reagent Answer : (a)
Q.3
Which one of the following undergoes reaction with 50% sodium hydroxide solution to give the corresponding alcohol and acid? ... ...[ AIEEE 2004]
0%
a) phenol
0%
b) benzoic acid
0%
c) butanal
0%
d) benzaldehyde
Explanation
Answer : (d)
Q.4
On heating calcium acetete and calcium format, the major product formed is
0%
a) CH3COCH3
0%
b) CH3CHO
0%
c) HCHO + CaCO3
0%
d) CH3CHO + CaCO3
Explanation
Answer : (d)
Q.5
Assertion: Benzaldehyde forms two oximes on reacting with NH2OH Reason: The two oximes are formed due to geometrical isomerism arised in product
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
0%
b) The Assertion and Reason are true but Reason is not correct explanation of Assertion
0%
c) Assertion is true but, Reason is false
0%
d) Assertion is false but, Reason is true
Explanation
Answer : (b)
Q.6
Which of the following would produce secondary alcohol?
0%
a)
0%
b)
0%
c)
0%
d)
Explanation
Answer : (a)
Q.7
Assertion: The major products formed by heating C6H5CH2OCH3 with HI are C6H5CH2I and CH3OH Reason: Benzyl cation is more stable than methyl cation
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
0%
b) The Assertion and Reason are true but Reason is not correct explanation of Assertion
0%
c) Assertion is true but, Reason is false
0%
d) Assertion is false but, Reason is true
Explanation
Answer : (a)
Q.8
A typical compound undergoes Cannizzaro's reaction as well as aldol condensation. The possible compound is
0%
a) C6H5CHO
0%
b) (CH3)2CHCHO
0%
c) CH3CH2CHO
0%
d) HCHO
Explanation
Certain aliphatic monoalylated aldehydes having α-hydrogen atom show aldol condensation as well as Cannizzaro reaction when heated with aqueous NaOH at 150-200°C Answer : (b)
Q.9
The difference between aldol condensation and Cannizzaro's reaction is that
0%
a) the former takes place in the presence of β-H-atom
0%
b) the former takes place in the presence of α-H-atom
0%
c) the former takes place in the absence of α-H-atom
0%
d) none of the above
Explanation
Aldol condensation: recation takes place in presence of α-H-atom Cannizzaro's reaction: recation takes place in absence of α-H-atom Answer : (c)
Q.10
Aldol condensation between the following comounds followed by dehydration gives methyl vinyl ketone
0%
a) methanal and ethanal
0%
b) two mole of formaldehyde
0%
c) methanal and propanone
0%
d) two mole of ethanal
Explanation
Answer : (c)
Q.11
The product(s) obtained via oxymercuration (HgSO4+H2SO4) of 1-butyne would be ... ..[ IIT 1999]
0%
b) CH3CH2CH2CHO
0%
c) CH3CH2CHO + HCHO
0%
a) CH3CH2COCH3
0%
d) CH3CH2COOH + HCOOH
Explanation
Answer : (a)
Q.12
C6H5CHO on reacting with Cl2 gives
0%
a) C6H5COCl
0%
b) C6H5CH2OH
0%
c) C6H5COOH
0%
d) C6H5CHCl2
Explanation
Answer : (a)
Q.13
Which of the following is correct?
0%
a) Aldehydes are more susceptible to oxidation than ketones
0%
b) Formaldehyde forms CH2(OH)NH2 with NH3
0%
c) All aldehydes undergo Cannizzaro's reaction
0%
d) Aldehydes are more susceptible to oxidation than ketones
Explanation
Answer : (a)
Q.14
The most reactive compound towards formation of cyanohydrin on treatment with HCN followed by acidification is
0%
a) p-Nitrobenzealdehyde
0%
b) p-Hydroxybenzaldehyde
0%
c) Benzaldehyde
0%
d) Phenyl acetaldehyde
Explanation
Presence of electron withdrawing group increases the reactivity of aromatic aldehydes towards nucleophilic addition reaction. Answer : (a)
Q.15
Which of the following contains ketene group? [ DEC 2005]
0%
a) -CH2 - CHO
0%
b) >C=C=O
0%
c) HCN
0%
d) -CH2-OH
Explanation
The compounds containing carbon-carbon double bond which has a cumulative relationship to the carbonyl >C=C=O Answer : (b)
Q.16
han One Correct Answer Q166) When a mixture of calcium acetate and calcium formate is heated, it yield(s)
0%
a) acetone
0%
b) acetaldehyde
0%
c) formic acid
0%
d) acetic acid
Explanation
Answer : (a,b)
Q.17
Which of the following has most acidic proton? ... [ Harayana CEET 1998]
0%
a) (CH3)2C = CH2
0%
b) (CH3CH2)3CH
0%
c) CH3COCH3
0%
d) CH3COCH2COCH3
Explanation
Proton of active methylene group is acidic in nature. has two electron withdrawing groups around -CH2 - which make it active methyl group Answer : (d)
Q.18
Reaction of metyl formate with excess of CH3MgI followed by hydrolysis gives
0%
a) ethanal
0%
b) iso-propyl alcohol
0%
c) n-propyl alcohol
0%
d) propanal
Explanation
Answer : (b)
Q.19
han One Correct Answers Q169) Which of the following reagents can be used to distinguish between an aldehyde and ketone?
0%
a) Tollen's reagent
0%
b) 2,4-dinitrophenyl hydrazine
0%
c) Acidified aqueous potassium dichromate solution
0%
d) Fehling's reagent
Explanation
Tollens' reagent is a chemical reagent used to determine the presence of aldehyde and aromatic aldehyde functional groups along with some alpha-hydroxy ketone which can tautomerize into aldehydealcohol and ketone respectively are not differentiated by Tollen's reagent. Dinitrophenylhydrazine is a red to orange solid. It is a substituted hydrazine, and is often used to qualitatively test for carbonyl groups associated with aldehydes and ketones In an aqueous solution the color change exhibited can be used to test for distinguishing aldehydes from ketones. Aldehydes reduce dichromate from the +6 to the +3 oxidation state, changing color from orange to green. This color change arises because the aldehyde can be oxidized to the corresponding carboxylic acid. A ketone will show no such change because it cannot be oxidized further, and so the solution will remain orange. Fehling's solution is a chemical reagent used to differentiate between water-soluble carbohydrate and ketone functional groups, Answer : (b,c,d)
Q.20
Self condensation of acetaldehyde in the presence of dilute alkalies gives ... ... [ Punjab CET 1990]
0%
a) An acetal
0%
b) An aldol
0%
c) Mesitylene
0%
d) Propionaldehyde
Explanation
Answer : (b)
Q.21
When propanone reacts with chlorine, it forms
0%
a) hexachloro propanone
0%
b) trichloro propanal
0%
c) trichloro propanone
0%
d) trichloro ethanol
Explanation
CH3COCH3 + Cl2 → CCl3.COCH3 Halogen attacks α-carbon atom Answer : (c)
Q.22
Which of the following contains pungention odour?
0%
a) Esters
0%
b) Highly aldehydes
0%
c) Lower aldehydes
0%
d) None of these
Explanation
Answer : (c)
Q.23
han One Correct Answer Q173) For separation of aldehyde or ketone from a non-carbonyl compound, mixture is first treated with .... and further regenerated with Na2CO3 solution
0%
a) NaHSO4
0%
b) HCN
0%
c) H2NOH
0%
d)
Explanation
Answer : (a,c)
Q.24
Acetaldehyde on oxidation with SeO2 give
0%
a) C2H5OH
0%
b) CHO.CHO
0%
c) CH3COOH
0%
d) none of these
Explanation
Answer : (b)
Q.25
on More Than One Correct Answer Q175) The product(s) is/are
0%
a) CH3CH2CHO
0%
b) CH3CH=CH2OH
0%
c) CH3COCH3
0%
d) none of these
Explanation
Answer : (a,b,c)
Q.26
Acetaldehyde and acetone can be distinguished by ... [ DCE 2003]
0%
a) DNP test
0%
b) Fehling's solution test
0%
c) Nitroprusside test
0%
d) Iodoform test
Explanation
Acetaldehyde reduces Fehling's solution giving red ppt. while acetone does not Answer : (b)
Q.27
Assertion: Addition of KCN solution to carbonyl compounds decreases the pH of solution Reason: KCN in aqueous solution forms a basic solution due to hydrolysis of CN-. The nucleophilic addition on carbonyl and brings in a decrease in H+ ions or an increase in OH- ions
0%
a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion
0%
b) The Assertion and Reason are true but Reason is not correct explanation of Assertion
0%
c) Assertion is true but, Reason is false
0%
d) Assertion is false but, Reason is true
Explanation
Answer : (d)
Q.28
Aniline reacts with which of these to form Schiff's base?
0%
a) NH3
0%
b) Benzaldehyde
0%
c) Acetic acid
0%
d) Acetone
Explanation
Answer : (d)
Q.29
Formaldehyde on condensation in presence of Ca(OH)2 gives
0%
a) fructose
0%
b) maltose
0%
c) formose
0%
d) xylose
Explanation
Answer : (c)
Q.30
Formalin is an aqueous solution of
0%
a) Furfural
0%
b) Fluorescein
0%
c) Formaldehyde
0%
d) Formic acid
Explanation
Formalin is 40% aqueous solution of formaldehyde Answer : (c)
0 h : 0 m : 1 s
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Report Question
×
What's an issue?
Question is wrong
Answer is wrong
Other Reason
Want to elaborate a bit more? (optional)
Support mcqgeeks.com by disabling your adblocker.
×
Please disable the adBlock and continue.
Thank you.
Reload page