12th class (Fsc) Chemistry unit 12 MCQs
26. When formaldehyde is heated with 50% of NaOH solution it undergoes:
a. Wurtz;s reaction
b. Cannizzaro;s reaction
c. Hydrolysis
d. Aldol condensation
27. Haloform reactions are only given by:
a. Acetaldehydes
b. Methyl ketones
c. Both a and b
d. None of these
28. Which one of the following reagents will react with both aldehydes and ketones?
a. Fehling’s reagent
b. Grignard reagent
c. Benedict’s reagent
d. Tollen’s reagent
29. The formation of cyanohydrin from a ketone is an example of:
a. Nucleophlic addition
b. Electrophilic substitution
c. Electrophilic addition
d. Nucleophlic substitution
30. Cannizzao’s reaction is not carried out by:
a. 2,2-Dimethyl propanal
b. Methanal
c. Ethanal
d. Benzaldehyde
31. Which one of the secondary alcohols gives iodoform test?
a. 3-pentanol
b. 2-propanol
c. 2-hexanol
d. 2-butanol
32. Which haloform test does not occur?
a. Flouroform test
b. Bromoform test
c. Iodoform test
d. Chloroform test
33. Disproportionation reaction is not given by:
a. Benzaldehyde
b. Formaldehyde
c. None of these
d. Acetaldehyde
34. Aldol compound consist of:
a. Carbooxylic group
b. Aldehyde group
c. None of these
d. Hydroxy group
35. Haloform test is given by the following aldehyde?
a. Benzaldehyde
b. Acetaldehyde
c. Formaldehyde
d. All
36. Which of the following compound will not iodoform test on treatment with I2 /NaOH:
a. 2-butanone
b. Acetaldehyde
c. 3-pentanone
d. Acetone
37. Acetaldehyde ammonia is used as:
a. Rubber accelerator
b. An antiseptic in halent in nasal infections
c. Decolorizing agent in vat dying
d. Hypnotic drugs
38. What is formation?
a. Formaldehyde+galactose
b. Formaldehyde+glucose
c. Formaldehydelactose
d. Formaldehyde+Maltose
39. Which is used as hypontic drugs?
a. Urea- Formaldehyde
b. Ethanal trimer
c. Chloral hydrate
d. Both b and c
40. In Fehling’s solution test an alkaline solutionis used which contain a?
a. Cupric lactate complex ion
b. Cupric tertarate complex ion
c. Cupric succinate complex ion
d. Cupric citrate complex ion
41. Formamint is used as:
a. Throat lozenges
b. Respiratory, antiseptic in lungs infection
c. An antiseptic in halent in nasal indections
d. None of these
42. Which one of the following is strong oxidizing agent?
a. Benedict’ solution
b. Fehling’s solution
c. Tollen’s solution
d. None of these
43. Which one of the following is used as urinary antiseptic?
a. Bakelite
b. Urea
c. Fromalin
d. Urotropine
44. The reduction of aldehydes and ketones can be done in the presence of which catalyst?
a. Ni
b. Pd
c. Any one of the given
d. Pt
45. Which one of the following used as ink preservative:
a. Ether
b. Alcohol
c. Phenol
d. Aldehyde
46. Which one of the followings compounds is not derivative of NH:
a. Phnyl hydrazine
b. Aniline
c. Picric acid
d. Hydrazine
47. Aldehydes and ketones with 2,4-dinitrophenyl hydrazine solution to give precipitate of the color:
a. White or red
b. Yellow or red
c. Black or red
d. Orange or red
48. Acetaldehyde polymerizes in the presence of dilute H2SO4 to form:
a. Protodormaldehyde
b. Metaformaldeyde
c. Bakelite
d. Paraldehyde
49. The reduction of ketone always gives:
a. Secondary alcohol
b. Ketal
c. Primary alcohol
d. Carboxylic acid
50. Aldehydes and ketones from hydrocarbons by:
a. Clemmensen’s reactions
b. Rosenmund’s reduction
c. None of these
d. Cannizzaro’s reaction