Alcohols Phenols and Ethers Test

Result

Alcohols Phenols and Ethers Test - 26

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

$$C_{2}H_{5}OH\overset{X}{\rightarrow}C_{2}H_{4}$$
In the given reaction, $$X$$ is:

A
acidic oxide of phosphorous

B
amphoteric oxide of zinc

C
basic oxide of calcium

D
amphoteric oxide of aluminium

Solution

$$Al_2O_3$$ is an effective deydrating agent promoting elimination reaction.
$$CH_3CH_2OH \longrightarrow CH_2=CH_2 + H_2O$$
Question 2
1 / -0

Which reagent can be used to convert ethanol to diethyl ether?

A
$$Al_{2}O_{3}$$ at $$250^{0}C$$

B
conc. $$H_{2}SO_{4}$$ at $$170^{0}C$$

C
conc. $$H_{2}SO_{4}$$ at $$130^{0}-140^0C$$

D
$$Al_{2}O_{3}$$ at $$350^{0}C$$

Solution

In this case, the ethanol is treated by concentrated sulphuric acid $$(H_2SO_4)$$ to form diethyl ether. The acid in an aqueous medium produces hydronium $$H_3O^+$$ ion.

$$H^+$$ protonate the oxygen atom of ethanol and the ethanol molecule gets a positively charged oxygen. After that, the oxygen atom of unprotonated ethanol abstracts a $$H_2O$$ molecule from ethanol and produces diethyl ether.

$$CH_3CH_2OH + H_2SO_4 \xrightarrow {140^oC} CH_3CH_2OH_2^+ + H_2O$$

$$CH_3CH_2OH_2^++CH_3CH_2OH \rightarrow CH_3CH_2OCH_2CH_3 + H_2O + H^+$$

So, the correct option is C
Question 3
1 / -0

Assertion: Dehydration of alcohols can be carried out with conc. $$H_{2}SO_{4}$$ but not with conc. $$HCl$$.
Reason: $$H_{2}SO_{4}$$ is dibasic while $$HCl$$ is monobasic.

A
Both Assertion and Reason are true and Reason is the correct explanation to Assertion

B
Both Assertion and Reason are true and Reason is not the correct explanation to Assertion

C
Assertion is true but Reason is false

D
Assertion is false but Reason is true

Solution

Dehydration of alcohols can be carried out with conc. $$H_2SO_4$$ as it is a dehydrating agent and removes a molecule of water from alcohols resulting in the formation of alkenes at higher temperatures. Conc. $$HCl$$ is not a dehydrating agent.
$$H_2SO_4$$ is indeed a dibasic acid and $$HCl$$ is not. But it is not the reason that $$HCl$$ is not a dehydrating agent.

So, both assertion and reason are true but the reason is not the correct explanation to assertion.
The correct option is 'B'.
Question 4
1 / -0

Which group can be completely displaced by a halogen group?

A
Hydroxyl group(OH)

B
Aldehyde $$(-CHO)$$ group

C
Nitro $$(-NO_{2})$$ group

D
Keto $$(C=O)$$ group

Solution

Hydroxyl group (-OH) present in an alcohol or an acid can be completely displaced by a halogen atom.
$$2C_2H_5OH+PCl_3 \rightarrow 2C_2H_5Cl + H_3PCl_3$$
Question 5
1 / -0

$$(CO+H_{2})+H_{2}\overset {673k,300atm,/Cr_{2}O_{3}-ZnO} {\rightarrow}$$
The above shown reaction may by used for manufacture of:

A
$$HCHO$$

B
$$CH_{3}COOH$$

C
$$HCOOH$$

D
$$CH_{3}OH$$

Solution

Methanol is prepared on an industrial scale from a mixture of CO and H2. The mixture is subjected to 200atm pressure and passed over ZnO and Cr2O3 catalyst at 400 to 450 degrees celsius.
Question 6
1 / -0

The most suitable method of separation of equal ($$1:1$$) mixture of ortho-nitrophenol and para-nitrophenol is:

A
Crystallisation

B
Distillation

C
Sublimation

D
Chromatography

Solution

The compound, o-nitrophenol shows intramolecular hydrogen bonding, whereas p-nitrophenol shows intermolecular hydrogen bonding.

Two molecules of p-nitrophenol associate to form a dimer. Such dimer formation is not possible in o-nitrophenol.

Hence, p-nitrophenol boils at a higher temperature because of this dimer formation.

Thus, the boiling point of o-nitrophenol is much lower than the boiling point of p-nitrophenol. Hence, these two isomers can be separated by distillation.

Option B is correct.
Question 7
1 / -0

The compound in which hydrogen bonding is not possible is:

A
$$CH_{3}OCH_{3}$$

B
$$CH_{3}CH_{2}OH$$

C
$$H_{2}O$$

D
$$CH_{3}COOH$$

Solution

Due to the presence of methyl groups that bounds to oxygen there is less tendency of hydrogen bonding in ethers.
Also, it does not have hydrogen attached to oxygen, so it can not form hydrogen bonds with itself.

The carboxylic acid, alcohol and water being polar show H-bonding.

Option A is correct.
Question 8
1 / -0

Which one of the following reagents can not cause $$C- O$$ bond fission in alcohols?

A
$$HCl /ZnCl_{2}$$

B
$$PCl_{5}$$

C
$$SOCl_{2}$$

D
Sodium

Solution

Unlike other reagents which promote a substitution reaction, Na only abstracts the proton. Hence, no $$C-O$$ bond fission takes place.
Question 9
1 / -0

Dehydration of alcohols can be done by using:

A
Conc. $$H_{2}SO_{4}$$

B
$$Al_{2}O_{3}$$

C
$$CaO$$

D
both A and B

Solution

Dehydration of alcohols can be done by:
a) Using aluminium oxide as catalyst.
This is a simple way of making gaseous alkenes like ethene. If ethanol vapour is passed over heated aluminium oxide powder, the ethanol is essentially cracked to give ethene and water vapour.

b) Using sulphuric acid at a temperature of 170°C.
Concentrated sulphuric acid produces messy results. Not only is it an acid, but it is also a strong oxidising agent. It oxidises some of the alcohol to carbon dioxide and at the same time is reduced itself to sulphur dioxide.

Both of these gases have to be removed from the alkene. It also reacts with alcohol to produce a mass of carbon. There are other side reactions as well.

Option D is correct.
Question 10
1 / -0

Which of the following pairs of reagents will not form ether?

A
$$C_{2}H_{5}Br+C_{2}H_{5}ONa$$

B
$$C_{2}H_{5}Br+CH_{3}ONa$$

C
$$CH_{3}Br+C_{2}H_{5}ONa$$

D
$$C_{2}H_{5}Br+HCOONa$$

Solution

If the reaction in D takes place, it will give esters and not ethers.

$$HCOONa + C_2H_5Br \rightarrow HCOOC_2H_5 +NaBr$$

Hence, D is the answer.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Alcohols Phenols and Ethers Test - 26

Result

Alcohols Phenols and Ethers Test - 26

Score

-

Rank

-

SHARING IS CARING

Question 1

acidic oxide of phosphorous

amphoteric oxide of zinc

basic oxide of calcium

amphoteric oxide of aluminium

Solution

Question 2

$$Al_{2}O_{3}$$ at $$250^{0}C$$

conc. $$H_{2}SO_{4}$$ at $$170^{0}C$$

conc. $$H_{2}SO_{4}$$ at $$130^{0}-140^0C$$

$$Al_{2}O_{3}$$ at $$350^{0}C$$

Solution

Question 3

Both Assertion and Reason are true and Reason is the correct explanation to Assertion

Both Assertion and Reason are true and Reason is not the correct explanation to Assertion

Assertion is true but Reason is false

Assertion is false but Reason is true

Solution

Question 4

Hydroxyl group(OH)

Aldehyde $$(-CHO)$$ group

Nitro $$(-NO_{2})$$ group

Keto $$(C=O)$$ group

Solution

Question 5

$$HCHO$$

$$CH_{3}COOH$$

$$HCOOH$$

$$CH_{3}OH$$

Solution

Question 6

Crystallisation

Distillation

Sublimation

Chromatography

Solution

Question 7

$$CH_{3}OCH_{3}$$

$$CH_{3}CH_{2}OH$$

$$H_{2}O$$

$$CH_{3}COOH$$

Solution

Question 8

$$HCl /ZnCl_{2}$$

$$PCl_{5}$$

$$SOCl_{2}$$

Sodium

Solution

Question 9

Conc. $$H_{2}SO_{4}$$

$$Al_{2}O_{3}$$

$$CaO$$

both A and B

Solution

Question 10

$$C_{2}H_{5}Br+C_{2}H_{5}ONa$$

$$C_{2}H_{5}Br+CH_{3}ONa$$

$$CH_{3}Br+C_{2}H_{5}ONa$$

$$C_{2}H_{5}Br+HCOONa$$

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.