Test: Tests And Distinction Of Alcohols


19 Questions MCQ Test Chemistry Class 12 | Test: Tests And Distinction Of Alcohols


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This mock test of Test: Tests And Distinction Of Alcohols for Class 12 helps you for every Class 12 entrance exam. This contains 19 Multiple Choice Questions for Class 12 Test: Tests And Distinction Of Alcohols (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Tests And Distinction Of Alcohols quiz give you a good mix of easy questions and tough questions. Class 12 students definitely take this Test: Tests And Distinction Of Alcohols exercise for a better result in the exam. You can find other Test: Tests And Distinction Of Alcohols extra questions, long questions & short questions for Class 12 on EduRev as well by searching above.
QUESTION: 1

Only One Option Correct Type

Direction (Q. Nos. 1-8) This section contains 8 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONLY ONE is correct.

Q. 

Which reagent can best distinguishes 3-pentanol and 3-methyl-3-pentanol?

Solution:

Chromic acid oxidises 3-pentanol but does not oxidise 3-methyl-3-pentanol (3°). Hence, 3-pentanol would change colour of chromic acid from orange to blue green but 3-methyl-3-pentanol does not.

QUESTION: 2

An organic compound X (C5H12O) gives effervescence with NaH. X on treatment with acidic CrO3 solution turns solution to blue-green forming C5H10O2. Also X can be resolved into enantiomers. The correct statement regarding X is

Solution:

X is a primary, chiral alcohol.

QUESTION: 3

An organic compound C4H10O (X) on reaction with I2/red-P give s C4H9I which on further reaction with AgNO2 gives C4H9NO2 (Y). Y on treatment with HNO2 forms a blue solution which turns to red on making solution slightly alkaline. The possible identity of X is

Solution:

X must be a primary alcohol as indicated by Victor Meyer's test. Both (a) and (b) are primary satisfy the condition.

QUESTION: 4

An organic compound X (C7H16O) on treatm ent with concentrated HCI solution forms immediate turbidity even in the absence of ZnCl2. Also, X is resolvable into enantiomers. The correct statement concerning X is

Solution:

QUESTION: 5

Which reagent given below does not produce any visible change when added to ethylene glycol?

Solution:

H2CO forms cyclic acetal with ethylene glycol but the change cannot be observed visually, in all other cases, change can be observed visually-effervescence with NaNH2 and NaH while colour change with CrO3 -H2SO4.

QUESTION: 6

Which of the following is least likely to form turbidity with HCI in the presence of ZnCI2 at room temperature?

Solution:

Although it is secondary alcohol, it forms a very unstable carbocation (Cl is electron withdrawing group), hence it does not give turbidity with Lucas reagent in cold condition.

QUESTION: 7

The correct statement regarding 3-ethyl-3-hexanol is

Solution:

All alcohols react (1°, 2° and 3°) with cerric nitrate and a colour change from yellow to red is observed.

QUESTION: 8

An alcohol has molecular formula C6H12O X and it gives immediate turbidity with cold, concentrated HCI even in the absence of ZnCI2. X can also be obtained by treatment of an ether with excess of CH3MgBr followed by acid hydrolysis. Hence, the correct statement regarding X is

Solution:

*Multiple options can be correct
QUESTION: 9

One or More than One Options Correct Type

Direction (Q. Nos. 9-12) This section contains 4 multiple choice questions. Each question has four choices (a), (b), (c) and (d), out of which ONE or MORE THAN ONE are correct.

Q. 

Which reagent(s) can be used to differentiate between 2-pentanol and 1-pentanol?

Solution:

2-pentanol forms yellow precipitate of CHI3 with I2/NaOH but 1-pentanol does not. 2-pentanol give immediate turbidity with Lucas reagent but 1 -pentanoi does not gives turbidity with Lucas reagent at room temperature. Both alcohols (1° and 2°) change colour of chromic acid solution from orange to blue green and both give effervescence of NH3(g) with NaNH2, hence these reagents cannot be used for distinction between 1° and 2° alcohols.

*Multiple options can be correct
QUESTION: 10

Alcohols given below that behaves like 1°-aliphatic alcohol in Lucas test is/are

Solution:

Both have electron withdrawing groups, destabilises carbocation, do not form turbidity with Lucas reagent at room temperature like primary alcohols. Option (b) and option (d) have electron donating groups, stabilises benzylic carbocation, forms immediate turbidity with Lucas reagent like 2° and 3° alcohols.

*Multiple options can be correct
QUESTION: 11

Consider the following reaction sequence,

R — OH  R — I R—NO2 Blue

Hence, R—OH could be

Solution:

Both primary and secondary alcohols form blue solution in Victor Meyer test due to the formation of respectively nitrolic acid and pseudonitrol. Tertiary alcohols form neither, hence no blue colouration is observed.

*Multiple options can be correct
QUESTION: 12

Consider the following reaction,

The correct statement(s) concerning X and Y is/are

Solution:


X neither oxidised by chromic acid nor gives iodoform.

QUESTION: 13

Comprehension Type

Direction (Q. Nos. 13-15) This section contains a passage describing theory, experiments, data, etc. Two questions related to the paragraph have been given. Each question has only one correct answer out of the given 4 options (a), (b), (c) and (d).

Passage

An organic compound X (C9H12O) gives the following reactions :
i. Na - Slow gas bubble formation
ii. Acetic anhydride - Pleasent smelling liquid
iii. CrO3-H2SO4 - Blue-green solution
iv. Hot KMnO4 - Benzoic acid
v. Br2-CCI4 - No decolouration
vi. I2 + NaOH - Yellow solid is formed
vii. X rotates the plane polarised light

Q. 

The structure of X is

Solution:


Also X, has CH3—CH(OH)—, gives iodoform test and it is chiral.

QUESTION: 14

An organic compound X (C9H12O) gives the following reactions :
i. Na - Slow gas bubble formation
ii. Acetic anhydride - Pleasent smelling liquid
iii. CrO3-H2SO4 - Blue-green solution
iv. Hot KMnO4 - Benzoic acid
v. Br2-CCI4 - No decolouration
vi. I2 + NaOH - Yellow solid is formed
vii. X rotates the plane polarised light

Q. 

If X is treated with HCI in the presence of ZnCI2, the major product would be

Solution:


Also X, has CH3— CH(OH)—, gives iodoform test and it is chiral.
 

QUESTION: 15

An organic compound X (C9H12O) gives the following reactions :
i. Na - Slow gas bubble formation
ii. Acetic anhydride - Pleasent smelling liquid
iii. CrO3-H2SO4 - Blue-green solution
iv. Hot KMnO4 - Benzoic acid
v. Br2-CCI4 - No decolouration
vi. I2 + NaOH - Yellow solid is formed
vii. X rotates the plane polarised light

Q. 

An isomer of X, Y was also found to be optically active. It showed the same reactions as X except (vi). Hence, Y is

Solution:


Also X, has CH3—CH(OH)—, gives iodoform test and it is chiral.

does not give iodoform test but gives all other reaction similar to X.

*Answer can only contain numeric values
QUESTION: 16

One Integer Value Correct Type

Direction (Q. Nos. 16-19) This section contains 4 questions. When worked out will result in an integer from 0 to 9 (both inclusive).

An organic compound X (C5H12O) is chiral. Also

Q.

How many primary hydrogens are present in X?


Solution:

X is a primary alcohol as indic ated by Victor Meyer test as well as it has a chiral carbon, hence

*Answer can only contain numeric values
QUESTION: 17

An alcohol X (C7H16O) gives immediate turbidity with HCI/ZnCI2 and can be resolved into enantiomers. Also X has a tertiary hydrogen. How many CH3— groups are present in X?


Solution:

Compound X satisfying the given criteria is

*Answer can only contain numeric values
QUESTION: 18

An alcohol X (C4H10O3) is chiral and absorbs two moles of HIO4 per mole of X. How many stereoisomers exist for X?


Solution:

X satisfying the given criteria is

Hence, X has four optically active isomers.

*Answer can only contain numeric values
QUESTION: 19

An organic compound X (C7H16O) gives effervescence with Na. X has both enantiomers and diastereomers. X gives yellow precipitate with alkaline iodine solution. With CrO3 - H2SO4 , X is converted into C7H14O (Y) which has enantiom ers but not diastereom ers. X on refluxing with H2SO4 isomerises to Z which neither gives yellow precipitate with alkaline iodine nor changes colour of CrO3 - H2SO4 . What is the minim um number of carbons that can be present in the parent chain of X ?


Solution:

From the give condition, structure of X is derived to be

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