PPSC Lecturer Chemistry Test 18 Online Preparation MCQs

Leave a Comment / By Hassan / October 8, 2020

Given below on this Website Online Free Taleem is free online MCQ’s test related to PPSC of Lecturer Chemistry. All the individuals who are going to appear in PPSC Lecturer of Chemistry written test can attempt these tests in order to prepare for it in best possible way. Our tests include all the important questions MCQs of Lecturer of PPSC Chemistry, all Past Papers of Lecturer of Chemistry PPSC that have extremely high amount of chances for been included in the actual exam which make our test undoubtedly the best source of preparation.

Note:-

There will be 25 multiple choice question in the test.
Answer of the questions will change randomly each time you start this test.
Practice this test at least 5 times if you want to secure High Marks.
At the End of the Test you can see your Test score and Rating.
If you found any incorrect answer in Quiz. Simply click on the quiz title and comment below on that MCQ. So that I can update the incorrect answer on time.

Please Click Below START Button to Take this Lecturer Chemistry Test Online.

Test Instructions:-
Test Name	Lecturer Chemistry
Subject	Chemistry Test 18
Test Type	MCQs
Total Questions	25
Total Time	20 Minutes
Total Marks	100

You have 20 minutes to pass to the quiz.

PPSC Lecturer of Chemistry Practice Test 18

1 / 25

Grignard reagents do not show any reaction with:

Alkanones

Acyl halides

Alkyl alkanoates

Alkoxyalkanes

2 / 25

Predict the two most likely mechanisms which occur when 2-iodohexane is heated in ethanol:

E1 and SN1

SN2 and SN1

SN2 and E2

E1 and E2

3 / 25

Which of the alkyl chlorides listed below undergoes dehydrohalogenation in the presence of a strong base to give 2-pentene as the only alkene product?

1-chloropentane

1-chloro-2-methylbutane

3-chloropentane

2-chloropentane

4 / 25

Predict the two most likely mechanisms for the reaction of 2-iodohexane with sodium ethoxide:

E1 and E2

E1 and SN1

SN2 and SN1

SN2 and E2

5 / 25

Which of the following compounds will undergo an SN2 reaction most readily?

(CH3)3CCH2I

(CH3)2CHI

(CH3)2CHCH2CH2CH2I

(CH3)3CCl

6 / 25

Which of the following statements is correct for a saturated alkyl halide?

the C–X bond results from overlap of the p orbital of carbon and the p orbital of the halogen (X)

the C–X bond results from overlap of the s orbital of carbon and the p orbital of the halogen (X)

the C–X bond results from overlap of the sp2 orbital of carbon and the p orbital of the halogen (X)

the C–X bond results from overlap of the sp3 orbital of carbon and the p orbital of the halogen (X)

7 / 25

Which of the following correctly reflects relative stabilities of carbocations?

2° allylic > 2° > vinyl

3° allylic > 2° > 1° benzylic

3° benzylic > vinyl > 1°

methyl > 2° benzylic > 3°

8 / 25

Which of the following is the strongest nucleophile in an aqueous solution?

I–

HO–

Br–

9 / 25

Which of the following is not correct concerning substitution and elimination reactions of alkyl halides?

Compounds containing electron-donating groups bonded to an sp3 hybridized carbon undergo substitution and elimination reactions

The electronegative atom is replaced by another atom or group in substitution reactions

(a) and (b)

The electrophile replaces the leaving group

10 / 25

Which of the following is a secondary alkyl halide?

(CH3)2CHCH2Br

CH3Br

(CH3)3CBr

(CH3)2CHBr

11 / 25

Which of the following halides is most reactive in an E2 reaction with sodium methoxide?

(CH3)3CCH2I

(CH3)2CHCH2Cl

(CH3)2CHCH2Br

(CH3)2CHCHICH3

12 / 25

Which is the most reactive alkyl halide in a SN1 reaction?

CH3I

CH3Cl

CH3F

CH3Br

13 / 25

Which of the following factors has no effect on the rate of SN1 reactions?

the concentration of the nucleophile

the nature of the leaving group

the nature of the alkyl halide

the concentration of the alkyl halide

14 / 25

Which of the following best describes the carbon-chlorine bond of an alkyl chloride?

polar; δ+ at carbon and δ– at chlorine

ionic

polar; δ– at carbon and δ+ at chlorine

nonpolar; no dipole

15 / 25

Which of the following is the best leaving group?

Cl–

I–

Br–

F–

16 / 25

The Grignard reagent, CH3CH2MgBr, can be used to prepare:

Propanoic acid

All of these

Ethane

3-Ethyl-3-pentanol

17 / 25

How should CH3CHClCH2CH3 be classified?

tertiary alkyl halide

primary alkyl halide

quarternary alkyl halide

secondary alkyl halide

18 / 25

Dehydrohalogenation of 2-bromobutane in the presence of a strong base proceeds via which of the following mechanistic pathways?

SN1

SN2

19 / 25

Which of the following halides is least reactive in an E2 reaction with sodium methoxide?

(CH3)3CCH2I

(CH3)2CHCHICH3

20 / 25

Which of the following is the best nucleophile in water?

I–

CH3SCH3

Cl–

21 / 25

Which of the following is the rate law for SN1 mechanisms?

Rate = k1[Alkyl Halide] + k2[Nucleophile]

Rate = k[Alkyl Halide]

Rate = k[Nucleophile]

Rate = k[Alkyl Halide] [Nucleophile]

22 / 25

Which of the following species is most reactive in a SN2 reaction?

CH3CH2Br

CH3CH2Cl

CH3CH2I

CH3CH2F

23 / 25

There are 8 isomers that have the molecular formula C5H11Br. How many of these are tertiary alkyl bromides?

24 / 25

Which of the following statements concerning SN2 reactions of alkyl halides is not correct?

The rate of reaction depends on the concentration of the nucleophile

The rate of reaction of a particular alkyl bromide depends on the steric accessibility of the carbon of the C-Br bond

All alkyl iodides react more rapidly than all alkyl chlorides. Answer

The rate of reaction depends on the concentration of the alkyl halide

25 / 25

Which of the following will have the lowest boiling point?

CHCl3

CH2Cl2

CH4

CH3Cl

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PPSC Lecturer Chemistry Test 18 Online Preparation MCQs

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