Generic selectors
Exact matches only
Search in title
Search in content
Search in posts
Search in pages
Filter by Categories
nmims post
Objective Type Set
Online MCQ Assignment
Question Solution
Solved Question
Uncategorized

Multiple choice question for engineering

Set 1

1. Hybridisation of Acetylene is
a) sp
b) sp2
c) sp3
d) dsp2

View Answer

Answer: a [Reason:] The Acetylene molecule is C2H2. It is sp hybridised.

2. Shape of PCl5 molecule is
a) Tigonal Planar
b) Linear
c) Trigonal bipyramidal
d) Tetrahedral

View Answer

Answer: c [Reason:] PCl5 is trigonal bipyramidal with its bond angle equal to 1200 and 900.

3. Predict the shape of the H2O compound based upon concepts of hybridisation.
a) Tetrahedral
b) Angular or bent structure
c) Trigonal Planar
d) Pyramidal

View Answer

Answer: b [Reason:] The water molecule has angular or bent structure due to the presence of two lone pairs which repels strongly.

4. Which of the following is an example of sp3d2 hybridised molecule?
a) HCHO
b) ClO4
c) SF6
d) PF5

View Answer

Answer: c [Reason:] The SF6 molecule is sp3d2 hybridised and the shape is regular octahedron.

5. Number of chlorine atoms which form equatorial bonds in PCl5 molecule are
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: c [Reason:] In PCl5 molecule, three chlorine atoms which lie at an angle of 1200 in the same plane forms equatorial bonds and the other two atoms forms axial bonds at an angle of 900.

6. Due to unsymmetrical structure, the molecules having sp3d hybridisation are
a) more stable and more reactive
b) less stable and more reactive
c) more stable and less reactive
d) less stable and less reactive

View Answer

Answer: b [Reason:] In sp3d hybridisation, due to its unsymmetrical structure the molecules are in the shape of trigonal bipyramidal which is less stable and more reactive.

7. The bond angles in sp3d2 hybridisation is
a) 900
b) 1200
c) 109.50
d) 1800

View Answer

Answer: a [Reason:] All the bond angles are equal in sp3d2 hybridisation i.e., 900.

8. The percentage p-character in sp3 hybridisation is
a) 25%
b) 50%
c) 75%
d) 66.67%

View Answer

Answer: c [Reason:] In sp3 hybridisation, s-character is 25% and p-character is 75%.

9. All the hybridised orbital are not equal in energy and shape.
a) True
b) False

View Answer

Answer: b [Reason:] All the hybridised orbital are equal in energy and shape. They are similar to each other and possess equal energy levels.

10. The hybridisation of BeF3– is
a) sp3
b) sp
c) sp2
d) d2sp3

View Answer

Answer: c [Reason:] The hybridisation of BeF3– is sp2 and it is trigonal planar.

Set 2

1. Which of the following is known as Baker-Nathan effect?
a) Mesomeric effect
b) Inductive effect
c) Hyperconjugation
d) Electromeric effect

View Answer

Answer: c [Reason:] Hyperconjugation is also known as Baker-Nathan effect. Hyperconjugation is the stabilising interaction that results from the interaction of the electrons in a σ-bond (usually C-H or C-C) with an adjacent empty or partially filled p-orbital or a π-orbital to give an extended molecular orbital that increases the stability of the system.

2. Hyperconjugation involves the delocalisation of
a) σ bond orbital
b) π bond orbital
c) Both σ and π bond orbital
d) None of the mentioned

View Answer

Answer: a [Reason:] Hyperconjugation involves the delocalisation of σ bond orbital. It is the stabilising interaction that results from the interaction of the electrons in a σ-bond (usually C-H or C-C) with an adjacent empty or partially filled p-orbital or a π-orbital to give an extended molecular orbital that increases the stability of the system.

3. Number of hyperconjugation structures in isopropyl radical is
a) 3
b) 6
c) 9
d) 12

View Answer

Answer: b [Reason:] Number of hyperconjugation structures in isopropyl radical is 6. Isopropyl is C3H7.

4. The resonance energy (kCal/mol) of tertiary butyl is
a) 9
b) 10
c) 11
d) 12

View Answer

Answer: d [Reason:] The resonance energy of tertiary butyl is 12 kCal/mol. It is also called tert-butanol, is the simplest tertiary alcohol, with a formula of (CH3)3COH It is one of the four isomers of butanol.

5. Larger the number of hyperconjugation structures, the stability of free radicals will
a) Increase
b) Decrease
c) Remain same
d) None of the mentioned

View Answer

Answer: a [Reason:] Larger the number of hyperconjugation structures, greater will be the stability of free radicals.

6. Which of the following is consequence of Baker-Nathan effect?
a) It is helpful in explaining the directive influence of alkyl groups in aromatic alkyl benzene
b) It is helpful in explaining the relative stability of alkenes
c) It is helpful in explaining the relative stabilities of alkyl carbocations
d) All of the mentioned

View Answer

Answer: d [Reason:] Baker-Nathan effect is helpful in explaining the directive influence of alkyl groups in aromatic alkyl benzene. It is helpful in explaining the relative stability of alkenes and relative stabilities of alkyl carbocations.

7. On increasing the number of α-hydrogens, the number of hyperconjugation structures will
a) Decrease
b) Increase
c) Remain same
d) None of the mentioned

View Answer

Answer: b [Reason:] On increasing the number of α-hydrogens, the number of hyperconjugation structures will increase. Hyperconjugatio is directly proportional to the number of α-hydrogens. α-hydrogen is the hydrogen atom attached to the carbon which is attached to functional group.

8. When the contributing structure contains the same number of two-electron bonds as the normal lewis formula, it will be
a) Heterovalent hyperconjugation
b) Sacrificial hyperconjugation
c) Isovalent hyperconjugation
d) All of the mentioned

View Answer

Answer: c [Reason:] When the contributing structure contains the same number of two-electron bonds as the normal lewis formula, it will be isovalent hyperconjugation.

9. The compound that can be most readily sulphonated is
a) Benzene
b) Toluene
c) Nitrobenzene
d) Chlorobenzene

View Answer

Answer: b [Reason:] The compound that can be most readily sulphonated is toluene. Toulene contains a methyl group with benzene ring and is a colorless, water-insoluble liquid with the smell associated with paint thinners.

10. State true or false. Ethene is devoid of any alpha hydrogen so hyperconjugation is not possible.
a) True
b) False

View Answer

Answer: a [Reason:] Ethene is devoid of any alpha hydrogen so hyperconjugation is not possible because presence of alpha hydrogen is the necessary condition for hyperconjugation.

Set 3

1. Electronegativity is defined as the power of an atom in a molecule to
a) Repel electrons towards itself
b) Attract electrons towards itself
c) Expand itself
d) All of the mentioned

View Answer

Answer: b [Reason:] Electronegativity is defined as the power of an atom in a molecule to attract electrons towards itself. Fluorine is the most electronegative element.

2. The factors on which electronegativity depends upon
a) Valence state of atom
b) Hybridisation
c) Both valence state and hybridisation
d) None of the mentioned

View Answer

Answer: c [Reason:] The factors on which electronegativity depends upon is valence state of atom and hybridisation.

3. How does the electronegativiy gets affected with the negative oxidation state?
a) It decreases
b) It increases
c) It remains constant
d) None of the mentioned

View Answer

Answer: a [Reason:] Electronegativity decreases with the negative oxidation state since the tendency to attract an electron will decrease with the negative charge of the anion.

4. The electronegativity of sp2 hybridised atom will be
a) 3.29
b) 2.48
c) 3.69
d) 2.75

View Answer

Answer: d [Reason:] The electronegativity of sp2 hybridised atom will be 2.75. Fluorine is the most electronegative element.

5. Which of the following is a permanent electron displacement effect?
a) Inductomeric
b) Electromeric
c) Inductive
d) All of the mentioned

View Answer

Answer: c [Reason:] Inductive effect is the permanent electron displacement effect and inductomeric and electromeric are temporary electron displacement effect.

6. Arrange the following groups in the order of decreasing (+I) effect.
a) C6H5O > COO > CR3 > CHR2 > H
b) C6H5O > H > CR3 > CHR2 > COO
c) CR3 > C6H5O > H > COO > CHR2
d) C6H5O > COO > CHR2 > CR3 > H

View Answer

Answer: a [Reason:] The correct order is- C6H5O > COO > CR3 > CHR2 > H.

7. Arrange the following groups in the order of decreasing (-I) effect.
a) CN > F > Br > Cl > COOH > I > H
b) COOH > CN > F > Br > Cl > I > H
c) H > COOH > CN > I > Cl > F > Cl
d) CN > COOH > F > Cl > Br > I > H

View Answer

Answer: d [Reason:] The correct order is- CN > COOH > F > Cl > Br > I > H.

8. Which of the following is application of inductive effect?
a) Bond length
b) Dipole moment
c) Strength of carboxylic acids
d) All of the mentioned

View Answer

Answer: d [Reason:] Bond length, dipole moment and strength of carboxylic acids are some of the applications of inductive effect.

9. Relative basic strength of amines does not depends upon
a) Inductive effect
b) Mesomeric effect
c) Steric effect
d) Stabilisation of cation by hydration

View Answer

Answer: b [Reason:] Relative basic strength of amines does not depends upon mesomeric effect. This effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures.

10. Due to presence of C – X polar bond in alkyl halide, alkyl halides are
a) More reactive than corresponding alkane
b) Less reactive than corresponding alkane
c) Equally reactive as corresponding alkane
d) None of the mentioned

View Answer

Answer: a [Reason:] Due to presence of C – X polar bond in alkyl halide, alkyl halides are more reactive than corresponding alkane.

Set 4

1. For a zero order reactions, the rate of reaction is independent of
a) Temperature
b) Nature of reactants
c) Concentration of reactants
d) Effect of catalyst

View Answer

Answer: c [Reason:] For a zero order reactions, the rate of reaction is independent of concentration of reactants. The rate law for a zero order reaction is R = K.

2. The half-life period of zero order reaction is directly proportional to the
a) Rate constant
b) Initial concentration of reactants
c) Final concentration of reactants
d) Concentration of products

View Answer

Answer: b [Reason:] The half-life period of zero order reaction is directly proportional to the initial concentration of reactants. It is given by: t1/2 = [A0] / 2K .

3. Which of the following is not an example of zero order reaction?
a) Photochemical combination of hydrogen and chlorine
b) Decomposition of ammonia over molybdenum surface
c) Thermal decomposition of HI on gold surface
d) Inversion of cane sugar in the presence of mineral acids

View Answer

Answer: d [Reason:] Inversion of cane sugar in the presence of mineral acids is not an example of zero order reaction. All the other options are the example of zero order reaction.

4. For a first order reaction, the half life period is independent of the
a) Initial concentration of the reactants
b) Final concentration of the reactants
c) Rate constant
d) Concentration of products

View Answer

Answer: a [Reason:] For a first order reaction, the half life period is independent of the initial concentration of the reactants. t1/2 = ln2 / K .

5. The thermal decomposition of nitrogen pentaoxide in gaseous phase is the example of
a) Zero order reaction
b) Half order reaction
c) First order reaction
d) Second order reaction

View Answer

Answer: c [Reason:] The thermal decomposition of nitrogen pentaoxide in gaseous phase is the example of first order reaction. A first order reaction depends on the concentration of only one reactant (a unimolecular reaction).

6. A compound decomposes according to the first order rate law with a half life period of 30 min. What will be the fraction of remaining compound after 120 min?
a) 0.625
b) 0.0625
c) 0.25
d) 0.025

View Answer

Answer: b [Reason:] k=0.693/t1/2 K= (2.303/t) log ([R0]/[Rt])

7. In a first order reaction, the time required for the completion of 99% is _______ for its 90% completion.
a) Same
b) Negligible
c) Thrice
d) Twice

View Answer

Answer: d [Reason:] In a first order reaction, the time required for the completion of 99% is twice for its 90% completion. ln [A] = -kt + ln [A0].

8. In a first order reaction, the time required for the completion of 99% is _______ times the time required for the completion of half of the reaction.
a) 5
b) 10
c) 20
d) 50

View Answer

Answer: b [Reason:] In a first order reaction, the time required for the completion of 99% is ten times the time required for the completion of half of the reaction. ln [A] = -kt + ln [A0].

9. The half life period of first order reaction is 15 min. Its rate constant will be equal to
a) 0.0462 min-1
b) 0.462 min-1
c) 0.00462 min-1
d) 0.562 min-1

View Answer

Answer: a [Reason:] k = 0.693/t1/2

10. State true or false. For a second order reaction, the rate is proportional to the square root of the concentration of the same reactant.
a) True
b) False

View Answer

Answer: b [Reason:] For a second order reaction, the rate is proportional to the square of the concentration of the same reactant.

11. Which of the following is not an example of second order reaction?
a) Oxidation of hydrogen bromide
b) Saponification of ester
c) Acid catalyzed hydrolysis of ester
d) Gaseous decomposition of hydrogen iodide

View Answer

Answer: c [Reason:] Acid catalyzed hydrolysis of ester is not an example of second order reaction. All the other options are the examples of second order reaction.

12. The half life period of nth order reaction varies inversely to ____________ th power of the initial concentration of the reactants.
a) n
b) 2n
c) (n+1)
d) (n-1)

View Answer

Answer: d [Reason:] The half life period of nth order reaction varies inversely to (n-1) th power of the initial concentration of the reactants. The half-life of a reaction describes the time needed for half of the reactant to be depleted.

13. The order of the reaction, if the time of half-completion is changed from 50 sec to 25 sec, when the initial concentration is changed from 0.5 to 1M will be
a) 0
b) 1
c) 2
d) 3

View Answer

Answer: c [Reason:] Tb / Ta = (a/b)n-1

Set 5

1. Ion-exchange resin is
a) Linear
b) Low molecular weight
c) Organic polymer with porous structure
d) Soluble

View Answer

Answer: c [Reason:] Ion-exchange resins are cross-linked, insoluble, high molecular weight, organic polymers with a porous structure.

2. Which of the following ion get released from the cation exchange column?
a) H+
b) Na+
c) K+
d) Ca+2

View Answer

Answer: a [Reason:] Only H+ ion get released from the cation exchange column.

3. Which of the following ion get released from the anion exchange column?
a) CO3-2
b) OH
c) Cl
d) SO4-2

View Answer

Answer: b [Reason:] Only OH ion get released from the anion exchange column.

4. Ion-free water coming out from the exchanger is known as
a) Potable water
b) Disinfected water
c) Coagulated water
d) Demineralised water

View Answer

Answer: d [Reason:] Ion-free water coming out from the exchanger is known as demineralised water as it is free from all the mineral impurities.

5. Which of the following statement is incorrect about the demineralised water?
a) It is as pure as distilled water
b) It is very good for use in high pressure boilers
c) It is fit for domestic use
d) It can be made either by distillation or by using cation and anion exchangers

View Answer

Answer: c [Reason:] Demineralised water is not recommended for domestic use such as drinking purposes. All the other options are correct.

6. The exhausted cation exchange column is regenerated by passing a solution of
a) Dil. HCl
b) Dil. NaCl
c) Conc. HCl
d) Conc. NaCl

View Answer

Answer: a [Reason:] The exhausted cation exchange column is regenerated by passing a solution of dil. HCl. Dil HCl is also known as brine solution.

7. The exhausted anion exchange column is regenerated by passing a solution of
a) Dil. KOH
b) Conc. KOH
c) Conc. NaOH
d) Dil. NaOH

View Answer

Answer: d [Reason:] By passing a solution of dil. NaOH, the exhausted anion exchange column is regenerated.

8. State true or false. The raw water used for ion-exchange process should be turbid.
a) True
b) False

View Answer

Answer: b [Reason:] The raw water used for ion-exchange process should be non-turbid and free from impurities.

9. In ion-exchange process, the capital cost is _________ and the operational expenses are ______________
a) Low, high
b) High, low
c) High, high
d) Low, low

View Answer

Answer: c [Reason:] In ion-exchange process, the capital cost is very high and the operational expenses are also high.

10. The residual hardness in ion-exchange process is
a) 0-2 ppm
b) 5-10 ppm
c) 10-15 ppm
d) 20-30 ppm

View Answer

Answer: a [Reason:] The residual hardness in ion-exchange process is 0-2 ppm. In waters containing more hardness than alkalinity, some hardness remains after treatment.