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Multiple choice question for engineering

Set 1

1. Reactions which are bimolecular yet following ___________ order kinetics are called pseudo unimolecular reaction.
a) Zero
b) First
c) Second
d) Third

View Answer

Answer: b [Reason:] Reactions which are bimolecular yet following first order kinetics are called pseudo unimolecular reaction. Pseudo means pretentious. Inversion of cane sugar is an example of pseudo first order reaction.

2. Which of the following is an example of pseudo first order reaction?
a) Saponification of ester
b) Oxidation of hydrogen bromide
c) Gaseous decomposition of hydrogen iodide
d) Inversion of cane sugar

View Answer

Answer: d [Reason:] Inversion of cane sugar is an example of pseudo first order reaction. All the other options are not the example of pseudo first order reaction.

3. Which concentration plot is linear for a first order reaction? ( A is one of the reactant)
a) [A] versus time
b) [A]2 versus time
c) Ln[A] versus time
d) √[A] versus time

View Answer

Answer: c [Reason:] The ln[A] versus time plot is linear and other graphs are curved for a first order reaction . For a zero order reaction, [A] versus time concentration plot is linear. For a second order reaction, 1/[A] versus time concentration plot is linear.

4. Based on the collision model, the atoms at the top of the potential energy hill are called
a) Transition state
b) Energetic atom
c) Steric factor
d) Activation energy

View Answer

Answer: a [Reason:] Based on the collision model, the atoms at the top of the potential energy hill are called transition state. The transition state is the state corresponding to the highest energy along the reaction coordinate. It has more free energy in comparison to the substrate or product; thus, it is the least stable state

5. What does termolecular refer to?
a) 2 molecules colliding
b) 3 molecules colliding
c) 4 molecules colliding
d) 5 molecules colliding

View Answer

Answer: b [Reason:] Termolecular means collision of three molecules. Ter refers to three.

6. For a certain reaction, the rate = k[NO]2[O2], when the initial concentration of NO is tripled, the initial rate
a) Increases by a factor of nine
b) Increases by a factor of three
c) Increases by a factor of six
d) Decreases by a factor of nine

View Answer

Answer: a [Reason:] For a certain reaction, the rate = k[NO]2[O2], when the initial concentration of NO is tripled, the initial rate increases by a factor of nine. Here, the reaction is of the order 3.

7. In a series of reactions, the rate determining step is
a) Simplest
b) Fast and complex
c) Fastest
d) Slowest

View Answer

Answer: d [Reason:] In a series of reactions, the rate determining step is the slowest step. The rate determining step is the slowest step of a chemical reaction that determines the speed (rate) at which the overall reaction proceeds.

8. Threshold energy is the sum of
a) Internal energy and external energy of reactants
b) Activation energy and external energy of reactants
c) Activation energy and internal energy of reactants
d) Activation energy and thermal energy

View Answer

Answer: c [Reason:] Threshold energy is the sum of activation energy and internal energy of reactants. The threshold energy for production of a particle is the minimum kinetic energy a pair of traveling particles must have when they collide.

Set 2

1. The basis of reverse osmosis is
a) Osmotic pressure is greater than hydrostatic pressure
b) Osmotic pressure is equal to hydrostatic pressure
c) Hydrostatic pressure is greater than osmotic pressure
d) Osmotic pressure does not exist

View Answer

Answer: c [Reason:] The basis of reverse osmosis is that the hydrostatic pressure is greater than osmotic pressure. It is a process by which a solvent passes through a porous membrane in the direction opposite to that for natural osmosis when subjected to a hydrostatic pressure greater than the osmotic pressure.

2. Select the incorrect statement from the following option.
a) Osmosis is the phenomenon by virtue of which flow of solvent takes placefrom low concentration to high concentration through a semi-permeable membrane
b) The flow continues till the concentration is equal on both the sides
c) The driving force of osmosis is osmotic pressure
d) Osmosis is used for the treatment of waste water

View Answer

Answer: d [Reason:] Reverse osmosis is used for the treatment of waste water. All the other options are correct. Osmosis is the phenomenon by virtue of which flow of solvent takes placefrom low concentration to high concentration through a semi-permeable membrane.

3. Semi-permeable membrane is selective membrane which does not permit the passage of dissolved ________ particles.
a) Solvent
b) Solute
c) Anhydrous
d) Saturated

View Answer

Answer: b [Reason:] Semi-permeable membrane is selective membrane which does not permit the passage of dissolved solute particles. It is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by diffusion

4. Which of the following is not used for semi-permeable membrane?
a) Polymethyl sulphate
b) Cellulose acetate
c) Polyamide polymer
d) Polymethyl acrylate

View Answer

Answer: a [Reason:] Polymethyl sulphate is not used for semi-permeable membrane. Cellulose acetate, polyamide polymer and polymethyl acrylate are used as semi-permeable membranes.

5. The pressure which is applied to separate the water from its contaminants is of the order
a) 5-10 kg/cm2
b) 15-40 kg/cm2
c) 50-100 kg/cm2
d) 100-150 kg/cm2

View Answer

Answer: b [Reason:] The pressure which is applied to separate the water from its contaminants is of the order 15-40 kg/cm2. It does not require very high pressure.

6. The process of reverse osmosis is also known as
a) Hyper-filtration
b) Double-filtration
c) Double-osmosis
d) Hyper-osmosis

View Answer

Answer: a [Reason:] The process of reverse osmosis is also known as super- or hyper-filtration. It is a process by which a solvent passes through a porous membrane in the direction opposite to that for natural osmosis when subjected to a hydrostatic pressure greater than the osmotic pressure.

7. Which of the following is not an application of reverse osmosis?
a) Desalination
b) Reclamation of minerals
c) For dialysis in hospitals
d) For industrial use

View Answer

Answer: d [Reason:] Reverse osmosis is not used for industrial purpose. All the other options are correct. It is used for desalination, reclamation of minerals and for dialysis in hospitals.

8. Select the incorrect statement about reverse osmosis from the following option.
a) It is simple and reliable process
b) It is relatively energy efficient
c) It operates at a comparatively high temperature
d) The life of a SPM is about 2 years and it can be easily replaced within a few minutes

View Answer

Answer: c [Reason:] Reverse osmosis operates at a comparatively low temperature. All the other options are correct. It is simple and reliable process, relatively energy efficient. The life of a SPM is about 2 years and it can be easily replaced within a few minutes.

9. The pH for the potable water should be in the range of
a) 5-6
b) 7-8.5
c) 9-10
d) 12-13

View Answer

Answer: b [Reason:] The pH for the potable water should be in the range of 7-8.5. It should not be acidic and also should not have high value of basicity. Hence, it’s value should be in the neutral range.

10. The total hardness of the potable water should be less than
a) 500 ppm
b) 700 ppm
c) 900 ppm
d) 1000 ppm

View Answer

Answer: a [Reason:] The total hardness of the potable water should be less than 500 ppm. Water having hardness more than 500 ppm is not safe for consumption.

Set 3

1. Which of the following is not a priority rule for R, S-Configuration?
a) If the four atoms attached to the chiral centre are all different, priority depends on atomic number, with the atom of lower atomic numbers getting lower priority
b) If the two atoms attached to chiral centre are same, the atoms attached to each of these first atoms are compared
c) When there is a double bond or triple bond, both atoms are considered to be duplicated or triplicated
d) If the four atoms attached to the chiral centre are all different, priority depends on atomic number, with the atom of higher atomic numbers getting lower priority

View Answer

Answer: d [Reason:] If the four atoms attached to the chiral centre are all different, priority depends on atomic number, with the atom of lower atomic numbers getting lower priority.

2. If our eyes travel in counter clockwise direction from the ligand of highest priority to the ligand of lowest priority, the configuration is
a) R-Configuration
b) S-Configuration
c) E-Configuration
d) C-Configuration

View Answer

Answer: b [Reason:] In S-Configuration, our eyes travel in counter clockwise direction from the ligand of highest priority to the ligand of lowest priority.

3. According to the selection rules, the decreasing order of preference is
a) –NH2 > -C6H5 > -CH(CH3)2 > -H
b) –CH(CH3)2 > -C6H5 > -H> -NH2
c) –NH2 > -CH(CH3)2 > -C6H5 > -H
d) -C6H5 > -CH(CH3)2 >–NH2 > -H

View Answer

Answer: a [Reason:] The atom of higher atomic numbers gets higher priority. So, –NH2 group has the highest priority of all.

4. The process of removal of hardness of water, irrespective of whether it is temporary or permanent is termed as
a) Cleansing action of water
b) Hardness of water
c) Softening of water
d) Purity of water

View Answer

Answer: c [Reason:] The process of removal of hardness of water, irrespective of whether it is temporary or permanent is termed as softening of water. This process includes both temporary as well as permanent hardness.

5. The external treatment of water does not include
a) Lime-soda process
b) Sequestration
c) Zeolites
d) Ion-exchange process

View Answer

Answer: b [Reason:] The external treatments of water include lime-soda, zeolites and ion-exchange processes. It does not include sequestration.

6. Which of the following conditioning method is not used in internal treatment?
a) Colloidal
b) Calgon
c) Carbonate
d) Bicarbonate

View Answer

Answer: d [Reason:] Colloidal, calgon, phosphate and carbonate conditioning method are used in internal treatment. Bicarbonate is not used for this purpose.

7. Select the incorrect statement from the following option.
a) Internal treatment is carried out outside the boiler, before water enters into the boiler
b) Internal treatment methods are followed by blow-down operations
c) Internal treatment is required in low pressure boilers
d) Internal treatment is a corrective method

View Answer

Answer: a [Reason:] Internal treatment is carried out inside the boiler. All the other options are correct.

8. State true or false. External treatment is a preventive method and it is required in high pressure boilers.
a) True
b) False

View Answer

Answer: a [Reason:] External treatment is a preventive method and it is required in high pressure boilers. External treatment is carried out outside the boilers.

9. Potable water treatment does not involve
a) Disinfection
b) Demineralisation
c) Coagulation
d) Sedimentation

View Answer

Answer: b [Reason:] Potable water treatment does not involve demineralisation. It involves disinfection, coagulation and sedimentation processes.

10. The exhausted anion exchangers can be regenerated by working with
a) Acid solution.
b) Alcohol solution
c) Alkali solution
d) Water

View Answer

Answer: c [Reason:] The exhausted anion exchangers can be regenerated by working with alkali solution because alkali solution or basic solution does not contains reactive ions.

Set 4

1. Silicones are called inorganic polymers due to absence of _________________in the main backbone chain.
a) Nitrogen atom
b) Oxygen atom
c) Carbon atom
d) Hydrogen atom

View Answer

Answer: c [Reason:] Silicones are called inorganic polymers due to absence of carbon atoms in the main backbone chain. Carbon compounds are the basis of organic chemistry.

2. Silicones resemble inorganic polymers in having high % of
a) Ionic character of Si-O bond
b) Organic groups on silicon atoms
c) Controlled hydrolysis
d) Solubility

View Answer

Answer: a [Reason:] Silicones resemble inorganic polymers in having high % of ionic character of Si-O bond. The bond between silicon and oxygen molecule is very ionic in nature.

3. The catalyst used in the preparation of poly-siloxanes is
a) Benzoyl peroxide
b) Grignard reagent
c) Cumene hydroperoxide
d) Lewis acid

View Answer

Answer: b [Reason:] The catalyst used in the preparation of poly-siloxanes is Grignard reagent. The Grignard reaction is an organometallic chemical reaction in which alkyl, vinyl, or aryl-magnesium halides, CH3MgI (Grignard reagents) add to a carbonyl group in an aldehyde or ketone.

4. Which of the following is tri-functional?
a) Dimethyl silicon chloride
b) Trimethyl silicon chloride
c) Tetramethyl silicon chloride
d) Momethyl silicon chloride

View Answer

Answer: d [Reason:] Momethyl silicon chloride is tri-functional and gives cross-linking to the final polymer.

5. Which of the following gives linear chain silicones on polymerisation by controlled hydrolysis?
a) Dimethyl silicon chloride
b) Trimethyl silicon chloride
c) Tetramethyl silicon chloride
d) Momethyl silicon chloride

View Answer

Answer: a [Reason:] Dimethyl silicon chloride gives linear chain silicones on polymerisation by controlled hydrolysis. All the other options does not give such type of reaction.

6. Which of the following is mono-functional?
a) Dimethyl silicon chloride
b) Trimethyl silicon chloride
c) Tetramethyl silicon chloride
d) Momethyl silicon chloride

View Answer

Answer: b [Reason:] Trimethyl silicon chloride is mono-functional and hence, a chain-stopper.

7. State true or false. The proportion of momethyl silicon chloride determines the amount of cross-linking that can be obtained in polymerisation.
a) True
b) False

View Answer

Answer: a [Reason:] The proportion of momethyl silicon chloride used in polymerisation determines the amount of cross-linking that can be obtained. It is made on an industrial scale as the principal precursor to dimethyl silicone and polysilane compounds.

8. On increasing the temperature, the viscosity of polysiloxanes
a) Increases
b) Decreases
c) Remain constant
d) First increases then decreases

View Answer

Answer: c [Reason:] The viscosity of polysiloxanes does not change appreciably with change in temperature.

9. The bond energy of Si-O bond is
a) 37 kJ/mol
b) 115 kJ/mol
c) 248 kJ/mol
d) 502 kJ/mol

View Answer

Answer: d [Reason:] The bond energy of Si-O bond is 502kJ/mol. The bond energy is a measure of the amount of energy needed to break apart one mole of covalently bonded gases and Si-O bond is very strong.

10. State true or false. Silicones have good electrical insulation because they are less stable to heat than organic polymers.
a) True
b) False

View Answer

Answer: b [Reason:] Silicones have good electrical insulation because they are more stable to heat than organic polymers.

Set 5

1. Soaps are _____________ based soapy detergents.
a) Water
b) Kerosene
c) Oil
d) Acid

View Answer

Answer: c [Reason:] Soaps are oil based soapy detergents. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution.

2. The saponification of a fat or oil is done using _______________ solution for hot process.
a) KOH
b) NaOH
c) HCl
d) NaCl

View Answer

Answer: b [Reason:] The saponification of a fat or oil is done using NaOH solution for hot process. Saponification to the sodium salt of myristic acid takes place with NaOH in water. NaOH gives hard soaps.

3. The saponification of a fat or oil is done using _______________ solution for cold process.
a) KOH
b) NaOH
c) HCl
d) NaCl

View Answer

Answer: a [Reason:] The saponification of a fat or oil is done using KOH solution for cold process. When potassium hydroxide (KOH) is used, a soft soap is formed. It cannot be used in hard water.

4. Soft soaps are the limitation of hot process because of their
a) High alkalinity
b) Low alkalinity
c) Low solubility in water
d) High solubility in water

View Answer

Answer: d [Reason:] Soft soaps are the limitation of hot process because of their greater solubility in water. When potassium hydroxide (KOH) is used, a soft soap is formed by cold process. It cannot be used in hard water.

5. Select the incorrect statement from the following option.
a) Hard soaps are the sodium carboxylates
b) Soft soaps are potassium carboxylates
c) Hard soaps are manufactured by cold process
d) Example of soft soap – shampoo and shaving cream

View Answer

Answer: c [Reason:] Hard soaps are manufactured by hot process and soft soaps are manufactured by cold process.

6. Which of the following is the residual product in the formation of soap?
a) Glyceraldehyde
b) Glycerol
c) Glycerine
d) Acrylonitrile

View Answer

Answer: b [Reason:] Glycerol is the residual product in the formation of soap. The immediate product is called an orthoester:

7. Which of the following is a typical soap molecule?
a) Calcium stearate
b) Potassium permanganate
c) Sodium bicarbonate
d) Sodium stearate

View Answer

Answer: d [Reason:] Sodium stearate is a typical soap molecule. Sodium stearate is the sodium salt of stearic acid. Sodium stearate has both hydrophilic and hydrophobic parts, the carboxylate and the long hydrocarbon chain, respectively.

8. The stearate ion has a ________ carbons long hydrocarbon chain.
a) 17
b) 19
c) 21
d) 23

View Answer

Answer: a [Reason:] The stearate ion has a 17 carbons long hydrocarbon chain, which is hydrophobic in nature.

9. Select the correct statement from the following options.
a) The soap micelle is unstable due to positive charge on its head
b) The soap micelle is stable due to positive charge on its head
c) The soap micelle is unstable due to negative charge on its head
d) The soap micelle is stable due to negative charge on its head

View Answer

Answer: d [Reason:] The soap micelle is stable due to negative charge on its polar head. It carries a negative charge due to attractive forces.

10. State true or false. Soaps do not act efficiently in hard water and in acidic solution.
a) True
b) False

View Answer

Answer: a [Reason:] Soaps do not act efficiently in hard water and in acidic solution due to their softness as compared to detergents. Soaps are the soft detergents and cannot be used in water containing calcium and magnesium salts..