Category: Engineering Chemistry Objective Questions

250+ TOP MCQs on Petroleum – 1 and Answers

Engineering Chemistry Multiple Choice Questions on “Petroleum – 1”.

1. Which region of the world contains the highest reserves of petroleum?
a) Western hemisphere
b) Middle East
c) Eastern hemisphere
d) North Pole
Answer: b
Clarification: 60% of the world reserves of petroleum are in the Middle East which includes parts of Saudi Arabia, Syria etc. 15 % of the reserves are present in the western hemisphere which are mainly contributed by the USA.

2. Petroleum is found in _____________
a) Core of earth
b) In Seas
c) In air
d) Crust of the earth
Answer: d
Clarification: Petroleum is a dark viscous liquid that is formed by the decomposition of dead animals in the earth’s crust for a long period of time. It is a complex mixture of hydrocarbons with small quantities of oxygen, nitrogen and sulphur.

3. According to the inorganic theory in which form does the petroleum is found under the earth’s crust?
a) Metal fluorites
b) Metal pyrites
c) Metal carbides
d) Metal oxides
Answer: c
Clarification: According to the inorganic theory for origin of petroleum, the metal carbides are formed under the earth’s crust due to the interaction of metals and carbon under high temperature and pressure. These carbides reacts with steam or water giving lower hydrocarbons which on further hydrogenation and polymerisation gives complex mixtures.

4. Which of the following point does the inorganic theory of the origin of petroleum fails to explain?
a) Presence of sulphur and nitrogen in the petroleum
b) Presence of uranium carbide in the petroleum
c) Presence of paraffinic molecules in the petroleum
d) Presence of olefinic molecule in the petroleum
Answer: a
Clarification: The theory given by Moison explains the presence of uranium carbide. Apart from S and N, presence of chlorophyll, haemen, prophyrin, and optically active compounds was not explained.

5. According to the organic theory, from which kind of compound does the petroleum is formed?
a) Plant debris
b) Animal and vegetable debris
c) From the decomposers
d) From sunlight
Answer: b
Clarification: According to the organic theory, petroleum is generated from the animal and vegetable debris accumulated in sea basins and buried by sand and slit. The debris is further decomposed by anaerobic bacteria under reducing conditions.

6. What is the role of high temperature and pressure in the making of petroleum (organic theory)?
a) For smooth flowing of petroleum
b) For generating good quality of petroleum
c) For decreasing the time required for its production
d) For providing a suitable condition for decomposers
Answer: d
Clarification: By providing high temperature and pressure, it creates a suitable condition for anaerobic respiration which further removes most of the oxygen present in them. It helps the anaerobic bacteria to decompose animal debris.

7. What type of compounds does the paraffin base oil contains?
a) Paraffin, olefin and aromatic compound
b) Paraffin, nitrogen and sulphur
c) Paraffin, naphthenes and aromatic compound
d) Paraffin, sulphur and aromatic compound
Answer: c
Clarification: Saturated paraffinic hydrocarbons are formed from methane to solid waxes. On distillation of this oil, it leaves a residue of solid paraffin wax. Small amounts of naphthenes and aromatic compounds are generated.

8. Which type of oil is obtained by the distillation of paraffin base oil?
a) Lubricating oil
b) Kerosene
c) Vegetable oil
d) Diesel
Answer: a
Clarification: Lubricating oil obtained from paraffin wax usually has lower specific gravity and higher viscosity index than that obtained from asphaltic base oils. Also, more solid waxes separate from the paraffin base lubricating oil on cooling.

9. Which kind of oils contain asphaltic, naphthenic and aromatic hydrocarbons?
a) Paraffin base oil
b) Asphaltic base oil
c) Mixed base oil
d) Other oils
Answer: b
Clarification: Asphaltic base oil consists of non-paraffinic hydrocarbons such as aromatic and naphthenic hydrocarbons. This oil on distillation leave behind asphalt and bitumen.

10. Mixed base oil does not act as an intermediate between paraffin and asphaltic base oils.
a) True
b) False
Answer: b
Clarification: It acts as an intermediate between paraffin and asphaltic base oils producing varying proportions of asphaltic, naphthenic and aromatic hydrocarbons. It does not produce bitumen on its distillation.

250+ TOP MCQs on Combustion Calculation and Answers

Engineering Chemistry Multiple Choice Questions on “Combustion Calculation”.

1. Which of the following law is not used in combustion calculation?
a) The law of conservation of mass
b) The law of definite proportion
c) The law of multiple proportion
d) The law of conservation of energy
Answer: c
Clarification: According to the law of multiple proportion, “If two elements combine together to form more than one compound, than the ratios of masses of the second element which combines with a fixed mass of first element will be ratios of small whole number”. Since combustion does not involve multiple elements, this law is not required.

2. Which of the following cannot be calculated in combustion calculation?
a) Calorific value of fuel
b) Composition of fuel
c) Composition of the flue gas
d) Nature of combustion
Answer: a
Clarification: The calorific value of coal can be calculated by using bomb calorimeter. If two of the following are given from composition of fuel, composition of the flue gas and nature of combustion than the third one can be calculated in the combustion.

3. Which of the following is the ideal gas equation for 1 mol of gas?
a) PV = nRT
b) PV = 6.022nRT
c) PR = nVT
d) PV = RT
Answer: d
Clarification: The ideal gas equation is as follows-
PV = nRT, since n=1
Therefore, PV=RT.
where P is pressure, V is volume, R is gas constant, T is temperature and n is the number of moles.
The value of R is 8.314 J/mol K.

4. What is the gram molecular volume of all gases at normal temperature pressure?
a) 2.24 L
b) 22.4 L
c) 224 L
d) 2240 L
Answer: b
Clarification: According to the Avogadro law, The gram molecular volume of all gases at N.T.P. (i.e., 0 0C and 760 mm abs) is 22.4 litres. The corresponding volume in the English system is 359 cu. Ft.

5. Which of the following laws can be used for calculating the volume of gas at a given temperature and pressure?
a) Boyle’s and Avogadro law
b) Charle’s and Avogadro law
c) Charle’s and Dalton’s law
d) Boyle’s and Charle’s law
Answer: d
Clarification: Boyle’s and Charle’s law can be used for reducing the volume of a gas at a given temperature and pressure to the corresponding volume at any other specific conditions of temperature and pressure with the help of the equation-
(PV)/T = (P1V1)/T1.

6. What is the absolute temperature of gases at N.T.P.?
a) -2730C
b) 2730C
c) -273 K
d) 273 K
Answer: a
Clarification: At N.T.P. the temperature is 0 0C. Therefore at absolute condition, the temperature will be, -2730C. The temperature will be equal to 0 K.

7. Which of the following reaction is not involved in combustion calculations?
a) CH4 + 2O2 → CO2 + 2H2O
b) 2C + O2 → 2CO
c) N2 + O2 → 2NO
d) 2H2 + O2 → 2H2O
Answer: c
Clarification: Combustion means conversion of a reactant in the form of CO2 and H2O. The CO obtained in 2C + O2 → 2CO option is again oxidized to form CO2. The calculation of combustion in done by taking number of moles in consideration.

8. Analysis for combustion of solids is always done on weight basis.
a) True
b) False
Answer: a
Clarification: The particles in solid are very closely packed due to which its volume does not gives accurate values of combustion. To overcome this problem, the combustion for solid is always calculated on the basis of weight. For gases and liquid the analysis is done on volume basis.

9. Find the volume of air required for complete combustion of 1 m3 of acetylene and the weight of air necessary for the combustion of 1 kg of fuel?
a) 10.6 m3 and 12.526 kg
b) 12.1 m3 and 15.5 kg
c) 11.9 m3 and 13.378 kg
d) 12.0 m3 and 14.965 kg
Answer: c
Clarification: The reaction involved in this reaction will be-
2C2H2 + 5O2 → 4CO2 + 2H2O
Therefore air required per m3 of C2H2 = 2.5 × (100/21) = 11.9 m3
Now oxygen supplied per kg of fuel = (162/52)
Therefore, air supplied per kg of C2H2 = (160/52) × (100/23) = 13.378 kg.

10. The % analysis by volume of product gas is H2 – 18.3%, CH2 – 3.4%, CO – 25.4%, CO2 – 5.1% and N2 – 47.8%. Calculate the volume of air required m3 of the gas?
a) 1.3643 m3
b) 1.5646 m3
c) 1.7643 m3
d) 1.9643 m3
Answer: a
Clarification: Total moles of O2 required = 28.65
Therefore, air required for 100 moles of fuel gas = 28.65 × (100/21) = 136.43 mols
Therefore air required per m3 of gas = (136.43/100) = 1.3643 m3.

250+ TOP MCQs on Applications of Electroplating and Answers

Engineering Chemistry Multiple Choice Questions on “Applications of Electroplating”.

1. What is the main principle of electroplating?
a) Hydrolysis
b) Neutralization
c) Esterification
d) Saturation
Answer: a
Clarification: Electroplating is the process by which a metal gets deposited over the other in the presence of metal salt (in aqueous solution). In this process, the water molecule is given out as the end product. Hence the principle behind electroplating is hydrolysis.

2. Which of the following is not an application of electroplating?
a) Decorative purposes
b) Coating of metal
c) Metal protection
d) Corrosion prevention
Answer: d
Clarification: Electroplating is the process by which a metal gets deposited over the other in the presence of metal salt (in aqueous solution). Hence it is used in decorative purposes, in coating other metals etc. It does not help in preventing corrosion (painting helps in preventing corrosion).

3. The process of modifying a metal’s properties is called _________________
a) Electrolysis
b) Electro deposition
c) Electro less plating
d) Electroplating
Answer: b
Clarification: Electroplating coats a thin layer of metal over the other metals but does not modify its properties. But electro deposition is the process by which the coating is permanent and the property of the coated metal changes.

4. What is a nickel strike?
a) Nickel deposition
b) Nickel coating
c) Nickel Plating
d) Nickel melting
Answer: a
Clarification: A strike layer, (also known as a flash layer), adhere to a thin layer of high-quality nickel plating to the base material (parent material). Once up to 0.1 millimeters of nickel coats the product, a lower quality current density is used to improve the speed of product completion towards electron deposition.

5. Saucepans can be prepared through electrolysis of __________________
a) Nickel
b) Galvanized zinc
c) Chromium
d) Copper
Answer: d
Clarification: In the manufacture of saucepan, a thin layer of copper is made as anode and a thick layer of copper is made of anode. Suitable metal to be coated is placed as a metal salt solution and the normal method of electrolysis is carried out.

7. Electroplating of chromium helps in preparing of ____________________
a) Car bumpers
b) Saucepans
c) Cutlery
d) Watches
Answer: a
Clarification: In the manufacture of bumpers a thin layer of chromium is made as anode and a thick layer of chromium is made of anode. Suitable metal to be coated is placed as a metal salt solution and the normal method of electrolysis is carried out.

8. Reactivity series of metals is called as the __________________________
a) Preferential series
b) Electrochemical series
c) Electrolytic series
d) Selective discharge series
Answer: b
Clarification: According to law of electrolysis, displacement series (ascending order of displacement capacity of different metals) is called electrolytic series. The reactivity series is hence called electrochemical series (ability to react more).

9. What happens if molten Lead Bromide (PbBr2) is electrolyzed?
a) At anode, brown fumes of bromide gas are given off
b) At anode, molten lead can be seen
c) At cathode, brown fumes can be seen
d) At cathode, lead bromide can be seen
Answer: a
Clarification: When molten lead bromide is electrolyzed, we get impurities on the cathode region and pure metal on the anode side. Also during deposition (due to high initial ignition), molten lead gets formed on the anode side.

10. Discharge difficulty is highest in _____________________
a) Calcium ions
b) Copper ions
c) Lead ions
d) Silver ions
Answer: a
Clarification: Since calcium is considered to be a heavy metal, usually discharge in the electrolysis of calcium far tedious as compared to other metals. (in the discharge scale, calcium has the highest discharge ability).

250+ TOP MCQs on Stereoselectivity and Stereospecificity and Answers

Engineering Chemistry Multiple Choice Questions on “Stereoselectivity and Stereospecificity”.

1. The reaction which gives exclusively one of several possible isomeric products is called ____________
a) Dynamicselective
b) Stereoselective
c) Regioselective
d) Stereospecific
Answer: c
Clarification: The reaction which gives exclusively one of several possible isomeric products is called regioselective reaction. Regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions.

2. The reaction that yields predominantly one enantiomer of a possible pair is called ____________
a) Dynamicselective
b) Stereoselective
c) Regioselective
d) Stereospecific
Answer: b
Clarification: The reaction that yields predominantly one enantiomer of a possible pair is called stereoselective reaction. Stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereo isomers during the non-stereo specific creation of a new stereo center or during the non-stereo specific transformation of a pre-existing one.

3. Stereoselectivity can be exhibited in various degrees.
a) True
b) False
Answer: a
Clarification: Stereoselectivity can be exhibited in various degrees like completely stereoselective, highly stereoselective, moderately stereoselective and so on.

4. The reaction in which stereochemically different molecules react differently is called ____________
a) Dynamicselective
b) Stereoselective
c) Regioselective
d) Stereospecific
Answer: d
Clarification: The reaction in which stereochemically different molecules react differently is called stereospecific reaction. Stereospecificity is the property of a reaction mechanism that leads to different stereo isomeric reaction products from different stereo isomeric reactants, or which operates on only one of the stereo isomers.

5. Which of the following is an example of regioselective reaction?
a) Debromination of 2,3- dibromobutane
b) 2-bromo octane with sodium hydroxide
c) Addition of HI to propylene
d) Debromination of meso dibromobutane
Answer: c
Clarification: Addition of HI to propylene is an example of regioselective reaction. Regioselectivity is the preference of one direction of chemical bond making or breaking over all other possible directions.

6. Reaction of (±) 2,3- dibromobutane is slower than meso in which the two methyl groups are ____________
a) Skew
b) Anti
c) Gauche
d) Partially eclipsed
Answer: d
Clarification: Reaction of (±) 2,3- dibromobutane is slower than meso due to higher transition state in which the two methyl groups are partially eclipsed.

7. Dynamic stereochemistry helps in correlating conformation and reactivity and in stereoselective synthesis.
a) True
b) False
Answer: a
Clarification: Dynamic stereochemistry helps in correlating conformation and reactivity and in stereoselective synthesis. Stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereo isomers during the non-stereo specific creation of a new stereo center

8. R – C = C – R reacts in the presence of lindlar catalyst to give a syn product. This is an example of ____________
a) Dynamicselective
b) Stereoselective
c) Regioselective
d) Stereospecific
Answer: b
Clarification: The above mentioned reaction is an example of stereoselective reaction. Stereoselectivity is the property of a chemical reaction in which a single reactant forms an unequal mixture of stereo isomers during the non-stereo specific creation of a new stereo center

9. Under SN2 conditions, on reaction with NaOH, (R)-2-bromo octane gives ____________
a) (S)-2-octanol
b) (R)-2-octanol
c) Trans-2-butene
d) Cis-2-butene
Answer: a
Clarification: Under SN2 conditions, on reaction with NaOH, (R)-2-bromo octane gives (S)-2- octanol. In SN2 mechanism, one bond is broken and one bond is formed synchronously.

10. Under SN2 conditions, on reaction with NaOH, (S)-2-bromo octane gives (R)-2-octanol. This is an example of ____________
a) Dynamicselective
b) Stereoselective
c) Regioselective
d) Stereospecific
Answer: d
Clarification: Under SN2 conditions, on reaction with NaOH, (S)-2-bromo octane gives (R)-2-octanol. This is an example of stereospecific reaction. In SN2 mechanism, one bond is broken and one bond is formed synchronously.

11. Optical purity is defined as the ____________
a) Ratio of rotation of pure enantiomer to rotation of mixture
b) Ratio of rotation of mixture to rotation of pure enantiomer
c) Product of rotation of mixture and rotation of pure enantiomer
d) Sum of rotation of mixture and rotation of pure enantiomer
Answer: b
Clarification: Optical purity is defined as the ratio of rotation of mixture to rotation of pure enantiomer. It is expressed as a percentage. If the sample only rotates plane-polarized light half as much as expected, the optical purity is 50%.

12. The formula of enantiomeric excess is ____________
a) [(d+l)/(d-l)]*100
b) [(d)/(d+l)]*100
c) [(d-l)/(d)]*100
d) [(d-l)/(d+l)]*100
Answer: c
Clarification: The formula of enantiomeric excess is [(d-l)/(d+l)]*100. It gives the percentage of excess of an enantiomer.

250+ TOP MCQs on Thin Layer Chromatography and Answers

Engineering Chemistry Multiple Choice Questions on “Thin Layer Chromatography”.

1. The principle on which thin layer chromatography is based is that the ____________
a) Different compounds are absorbed on an absorbent to different degrees
b) Different compounds are absorbed on an absorbent to same degrees
c) Different compounds are adsorbed on an adsorbent to different degrees
d) Different compounds are absorbed on an absorbent to same degrees
Answer: c
Clarification: Thin layer chromatography is based on the fact that different compounds are adsorbed on an adsorbent to different degrees. It is a chromatography technique used to separate non-volatile mixtures.

2. The size of a thin layer of adsorbent is about ____________
a) 0.1 mm
b) 0.2 mm
c) 0.3 mm
d) 0.4 mm
Answer: b
Clarification: The size of a thin layer of adsorbent is about 0.2 mm. TLC plates are usually commercially available, with standard particle size ranges to improve reproducibility.

3. The chromaplate or thin layer chromatography plate is made up of ____________
a) Glass
b) Wood
c) Fibre
d) Metal
Answer: a
Clarification: The chromaplate or thin layer chromatography plate is made up of glass. TLC plates are usually commercially available, with standard particle size ranges to improve reproducibility. They are prepared by mixing the adsorbent, such as silica gel, with a small amount of inert binder like calcium sulfate (gypsum) and water.

4. The eluant filled in the closed jar is ____________
a) Mixture of gases
b) Mixture of a liquid and a gas
c) Mixture of solids
d) Mixture of liquids
Answer: d
Clarification: The eluant filled in the closed jar is liquid or mixture of liquids.

5. Select the incorrect statement from the following options.
a) The spots of colorless compounds are invisible to the eyes
b) These spots can be detected by putting the plate under ultraviolet light
c) These spots can be detected by placing the plate in a covered jar containing iodine crystals
d) None of the mentioned
Answer: d
Clarification: All the mentioned options are correct. The spots of colorless compounds are invisible to the eyes, can be detected by putting the plate under ultraviolet light and can be detected by placing the plate in a covered jar containing iodine crystals.

6. The relative adsorption of each component of the mixture is expressed in terms of its ____________
a) Acceleration factor
b) Retardation factor
c) Both acceleration and retardation factor
d) None of the mentioned
Answer: b
Clarification: The relative adsorption of each component of the mixture is expressed in terms of its retardation factor (Rf).

7. Select the correct statement from the following.
a) Paper chromatography is a type of partition chromatography
b) A special quality paper is used in paper chromatography
c) Chromatography paper contains water trapped in it, which acts as stationary phase
d) All of the mentioned
Answer: d
Clarification: Paper chromatography is a type of partition chromatography. A special quality paper is used in paper chromatography which contains water trapped in it, which acts as a stationary phase.

8. Amino acids detected by spraying the plate with ninhydrin solution is an example of ____________
a) Column chromatography
b) Thin layer chromatography
c) Paper chromatography
d) Liquid chromatography
Answer: c
Clarification: Amino acids detected by spraying the plate with a ninhydrin solution is an example of paper chromatography. Paper chromatography is an analytical method that is used to separate colored chemicals or substances.

9. Paper chromatography is based on continuous differential partitioning of components of a mixture between stationary and mobile phases.
a) True
b) False
Answer: a
Clarification: Paper chromatography is based on a continuous differential partitioning of components of a mixture between stationary and mobile phases. It is an analytical method that is used to separate colored chemicals or substances.

10. Retardation factor is the ratio of ____________
a) Distance moved by substance from base line to distance moved by the solvent from base line
b) Distance moved by solvent from base line to distance moved by the substance from base line
c) Distance moved by substance from top line to distance moved by the solvent from top line
d) Distance moved by solvent from top line to distance moved by the substance from top line
Answer: a
Clarification: Retardation factor is the ratio of the distance moved by substance from base line to distance moved by the solvent from base line.

250+ TOP MCQs on Hyperconjugation and Answers

Engineering Chemistry Multiple Choice Questions on “Hyperconjugation”.

1. Which of the following is known as Baker-Nathan effect?
a) Mesomeric effect
b) Inductive effect
c) Hyperconjugation
d) Electromeric effect
Answer: c
Clarification: 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
Answer: a
Clarification: 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
Answer: b
Clarification: 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
Answer: d
Clarification: 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) Remains same
d) None of the mentioned
Answer: a
Clarification: Larger the number of hyperconjugation structures, greater will be the stability of free radicals.

6. Which of the following is a 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
Answer: d
Clarification: 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) Remains same
d) None of the mentioned
Answer: b
Clarification: On increasing the number of α-hydrogens, the number of hyperconjugation structures will increase. Hyperconjugation is directly proportional to the number of α-hydrogens. α-hydrogen is the hydrogen atom attached to the carbon which is attached to a 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
Answer: c
Clarification: 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
Answer: b
Clarification: 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. Ethene is devoid of any alpha hydrogen so hyperconjugation is not possible.
a) True
b) False
Answer: a
Clarification: Ethene is devoid of any alpha hydrogen so hyperconjugation is not possible because the presence of alpha hydrogen is the necessary condition for hyperconjugation.