Category: Engineering Chemistry Objective Questions

Engineering Chemistry Multiple Choice Questions on “Gaseous Fuels – 1”.

1. Which of the following is a disadvantage of gaseous fuel?
a) Gaseous fuels are very difficult to operate
b) Gaseous fuels are highly inflammable
c) Gaseous fuels cannot be ignited instantly
d) They produce lot of smoke on combustion
Answer: b
Clarification: The particles in gaseous fuels are separated from each other, due to which their combustion becomes very easy. This increases the inflammability of the gaseous fuel. Special care should be taken to avoid fire hazards.

2. Which of the following is a major advantage of gaseous fuel over liquid and solid fuel?
a) Gaseous coal does not form ash
b) Gaseous coal can be manufactured at a central place
c) Oxidising and reducing atmospheres can be easily maintained
d) They are economic than solid and liquid fuels
Answer: a
Clarification: Ash content is present in the fuel itself. Due to the presence of ash content in solid and liquid fuels, its rate of combustion decreases. Also, a lot of smoke is generated due to the presence of ash content.

3. Which of the following is a primary gaseous fuel?
a) Water gas
b) Oil gas
c) Refinery gas
d) Liquefied petroleum gas
Answer: d
Clarification: Primary gaseous fuel are those, which are already present in nature and secondary gaseous fuels are those which are obtained from primary gaseous fuels. Natural gas is also a primary gaseous fuel.

4. Which of the following compound is present in natural gas?
a) Urea
b) Benzoyl peroxide
c) Methane
d) Sulphonic acid
Answer: c
Clarification: Natural gas is mainly composed of methane and small quantities of ethane and other hydrocarbons. Urea consists of nitrogen due to which it is not present in natural gas.

5. Which type of natural gas is called wet natural gas?
a) Containing lower hydrocarbon with more ethane
b) Containing higher hydrocarbon with more ethane
c) Containing lower hydrocarbon with more methane
d) Containing higher hydrocarbon with more methane
Answer: d
Clarification: If higher hydrocarbons are present along with methane, then the natural gas is called “Rich” or “Wet” natural gas. It is also called “Marsh gas” because it majorly contains methane.

6. From which of the following natural gas is majorly obtained?
a) From oil fields
b) From coal fields
c) From seas
d) From sun
Answer: a
Clarification: Most of the natural gas used as fuel is derived from oil fields. However, sometimes, the gas is evaporated from the oil and diffused through rocks, is trapped by impervious dome shaped structure.

7. Which of the following natural gas has the highest ignition temperature?
a) Natural gas obtained from oil fields
b) Natural gas obtained from coal fields
c) Natural gas obtained from rocks
d) Natural gas obtained from sea
Answer: c
Clarification: The natural gas produced from rocks by the diffusion of oil constituents a gas field that may be under high pressure. Due to this high pressure, the flow potential of gas increase, which produces static electricity and increases the ignition temperature which is hazardous for us.

8. How much percentile of propane is present in natural gas?
a) 5.5 %
b) 3.7 %
c) 1.8 %
d) 0.5 %
Answer: b
Clarification: At an average 88.5 % of methane is present in natural gas. 5.5 % of ethane, 3.7 % of propane and 1.8 % of butane are present in natural gas. The higher hydrocarbons are present at about 0.5 %.

9. H₂S is not present in natural gas.
a) True
b) False
Answer: b
Clarification: H₂S is present in small quantity in natural gas. If it is present in an appreciable amount, then it is called as “Sour” natural gas. At the maximum 15 % of H₂S in found in natural gas till now.

10. Which of the following process is used to recover vapours of liquid hydrocarbons in wet natural gas?
a) Evaporation
b) Distillation
c) Cracking
d) Adsorption
Answer: d
Clarification: The vapours of liquid hydrocarbons can be recovered by condensation, absorption in oil and by adsorption on charcoal, silica or alumina gel. The liquid so recovered is called casinghead gasoline.

Engineering Chemistry test focuses on “Factors Influencing Corrosion”.

1. Which of the following factor influences the rate and extent of corrosion?
a) Nature of metal only
b) Nature of the environment only
c) Both nature of metal and environment
d) Nature of reaction
Answer: c
Clarification: Both nature of metal and environment influence the rate and extent of corrosion as corrosion is a natural process, which converts a refined metal to a more stable form, such as its oxide, hydroxide, or sulfide.

2. Which of the following is not associated with the nature of metal?
a) Nature of oxide film
b) Nature of electrolyte
c) Purity
d) Physical state
Answer: b
Clarification: Nature of metal includes its purity, physical state, nature of oxide film, position in galvanic series, etc and hence it is not associated with the nature of electrolyte.

3. Which of the following is not associated with the nature of the environment?
a) Humidity
b) Temperature
c) Effect of pH
d) Volatility of corrosion products
Answer: d
Clarification: Nature of the environment includes temperature, humidity, effect of pH, nature of electrolyte, etc and hence volatility of corrosion product is not associated with it.

4. Lesser is the purity of the percentage of metal, faster is the rate of corrosion.
a) True
b) False
Answer: a
Clarification: Lesser is the purity of the percentage of metal, faster is the rate of corrosion. Pure metals does not corrose easily whereas impure metals corrode easily.

5. Rate of corrosion of anodic region is inversely proportional to the ___________
a) Cathodic area
b) Anodic area
c) Product of anodic area and cathodic area
d) Sum of anodic area and cathodic area
Answer: b
Clarification: Rate of corrosion of the anodic region is inversely proportional to the anodic area. Greater will be the anodic area, faster will be the corrosion at an anode.

6. Corrosion of zinc can be minimized by increasing the pH to ___________
a) 9
b) 10
c) 11
d) 12
Answer: c
Clarification: Corrosion of zinc can be minimized by increasing the pH to 11. pH 11 means it will be basic in nature and hence will be less prone to corrosion.

7. Which of the following medium is most corrosive?
a) Acidic
b) Alkaline
c) Neutral
d) Both acidic and basic
Answer: a
Clarification: Acidic medium is more corrosive than alkaline and neutral media. In acidic medium, metals are more reactive and more prone to corrosion.

8. Which of the following is an example of an inactive atmospheric suspended particle?
a) NaCl
b) (NH₄)₂ SO₄
c) AlCl₃
d) Charcoal
Answer: d
Clarification: Charcoal is an example of an inactive atmospheric suspended particle. Charcoal is obtained by removing water and other volatile constituents from animal and vegetation substances.

9. Excessive corrosion of metal takes place if corrosion product is ___________
a) Volatile
b) Non-volatile
c) Both volatile as well as non-volatile
d) Initially volatile and then non-volatile
Answer: a
Clarification: Excessive corrosion of metal takes place if corrosion product is volatile. When the corrosion product is volatile it easily escapes with gases and hence allowing more metal to corrode.

10. The specific volume ratios of W, Cr and Ni are 3.6, 2.0 and 1.6 respectively. Which of them will have the least rate of corrosion?
a) Ni
b) Cr
c) W
d) All will have the same rate of corrosion
Answer: c
Clarification: W will have the least rate of corrosion, even at higher temperatures because the specific volume ratio is inversely proportional to the rate of corrosion.

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Engineering Chemistry Multiple Choice Questions on “Catalysis Reactions”.

1. The following reaction is an example of _____________
2SO₂ + O₂ ⟶ 2SO₃
a) Homogeneous catalysis
b) Heterogeneous catalysis
c) Mixed catalysis
d) Demoivre catalysis
Answer: a
Clarification: We can see from the problem that all the individual species are in gaseous form. Since all the species are in the same phase, the reaction is an example of homogeneous reaction.

2. The following reaction is an example of _________
N₂ + 3H₂ ⟶ 2NH₃
a) Homogeneous catalysis
b) Heterogeneous catalysis
c) Mixed catalysis
d) Demoivre catalysis
Answer: b
Clarification: Since we can see from the reaction that ammonia which is formed at the right hand side is solid in phase and the other reactants are gaseous, the individual species are of different phases and hence it is an example of heterogeneous reaction.

3. The following reaction is an example of __________________
Na + Cl ⟶ NaCl
a) Homogeneous catalysis
b) Heterogeneous catalysis
c) Mixed catalysis
d) Demoivre catalysis
Answer: c
Clarification: We can see from the above reaction that the sodium and chlorine atoms combine together to give a colourless solution that is the ions in this process and hence this reaction is an example of a mixed reaction.

4. The following reaction is an example of __________________
Sodium sulphite + oxygen ⟶ sodium sulphate
a) Homogeneous catalysis
b) Heterogeneous catalysis
c) Mixed catalysis
d) Demoivre catalysis
Answer: d
Clarification: We can see from the above reaction that the same component has transformed itself with more number of one types of atom (here it is oxygen). Thus this reaction is an example of Demoivre catalysis.

5. Which theory relatively suits or heterogeneous catalysis?
a) Intermediate
b) Absorption
c) Nucleate
d) Paratoid
Answer: b
Clarification: Since in a heterogeneous compound, more than one molecule is involved, the main component splits itself into sub parts before disintegration. This theory is called as absorption theory.

6. Which theory best suits for homogeneous catalysis?
a) Intermediate
b) Absorption
c) Nucleate
d) Paratoid
Answer: a
Clarification: Since in a homogeneous compound, only single atom is present, it will form either an intermediate carbocation or cabanion. This theory is called the intermediate theory.

7. Which theory best suits for mixed catalysis?
a) Intermediate
b) Absorption
c) Nucleate
d) Paratoid
Answer: c
Clarification: In the case of mixed catalysis, individual ion species are involved and they will form ionic solutions with solvents, and this reaction is called nucleate reaction.

8. Which theory best suits for Demoivre catalysis?
a) Intermediate
b) Absorption
c) Nucleate
d) Paratoid
Answer: d
Clarification: Since in Demoivre catalysis, the same component is converted into a form having a higher amount of specific molecule, such reaction holds good for paratoid theory.

9. Calculate the amount of intermediate formed from the following data.
Initial amount=10
Final amount=20
a) 2
b) 5
c) 10
d) 1
Answer: c
Clarification: We know that the amount of intermediate formed is nothing but the difference in the initial and final amount of the compound used. Hence here it is 20-10=10.

10. Calculate the amount of intermediate formed from the following data.
Initial amount=100
Final amount=900
a) 200
b) 800
c) 100
d) 1000
Answer: b
Clarification: We know that the amount of intermediate formed is nothing but the difference in the initial and final amount of the compound used. Hence here it is 900-100=800.

Engineering Chemistry Multiple Choice Questions on “Homonuclear and Heteronuclear Molecules”.

1. Which of the following molecule is not homonuclear?
a) H₂
b) N₂
c) NO
d) O₂
Answer: c
Clarification: NO is Heteronuclear diatomic molecule in which atomic number of nitrogen is 7 and that of oxygen is 8 i.e., total number of electrons = 15.

2. Bond order of NO⁺ molecule is _________
a) 2
b) 3
c) 2.5
d) 4
Answer: b
Clarification: Bond order = (10-4)/2 = 3.

3. Which of the following molecule is least stable?
a) NO⁺
b) N₂
c) NO
d) O₂
Answer: c
Clarification: In NO molecule there is a significant difference of about 250 kJ/mol in the energy of atomic orbitals involved.

4. The molecular orbital electronic configuration of HF molecule is _________
a) 1s² 2s² σ_spx² [2_py² 2_pz²] σ_spx*
b) 1s² 2s² σ_spx² [2_px² 2_py²] σ_spx*
c) 1s² 2s² σ_spx² [2_px² 2_pz²] σ_spx*
d) 1s² 2s² σ_spx² [2_px⁴] σ_spx*
Answer: a
Clarification: HF molecule has 10 electrons and its electronic configuration is 1s² 2s² σ_spx² [2_py² 2_pz²] σ_spx*.

5. From the following options, choose the heteronuclear diatomic molecules which are paramagnetic in nature?
a) HF and NO
b) HF and O₂
c) NO and O₂
d) Only NO
Answer: d
Clarification: HF is diamagnetic in nature and O₂ is homonuclear molecule. So, only NO is a heteronuclear diatomic molecule that is paramagnetic in nature.

6. Calculate the number of σ and π bonds in cyclohexadiene. (C₆H₈)
a) σ bond = 2, π bond = 14
b) σ bond = 14, π bond = 2
c) σ bond = 12, π bond = 2
d) σ bond = 12, π bond = 4
Answer: b
Clarification: Cyclohexadiene molecule has two double bonds(hence two π-bonds) and one ring.

7. The combination of H (1s¹) and F (2px¹) gives _________
a) Bonding orbital
b) Antibonding orbital
c) Both bonding and antibonding orbital
d) None of the mentioned
Answer: c
Clarification: The combination of H (1s1) and F (2px1) gives both bonding (σ_spx) and antibonding (σ_spx*) orbitals.

8. Choose the incorrect option from the following.
a) Valence bond theory does not explain the paramagnetic nature of O₂
b) Molecular orbital theory explains the extra stability of O₂⁺ cation over O₂
c) Valence bond theory explains the ionization or gain of electrons, giving O₂⁺ and O₂^– ions, if O₂ has the stable octet
d) Resonance has no role in Molecular orbital theory
Answer: c
Clarification: Valence bond theory does not explain the ionization or gain of electrons, giving O₂⁺ and O₂^– ions, if O₂ has the stable octet.

9. Which of the following molecules have bond order equal to 1?
a) NO, HF, HCl, Li₂, CO
b) H₂, Li₂, B₂, HF, HCl
c) Li₂, B₂, CO, NO,He₂⁺
d) B₂, CO, He₂⁺, NO, HF
Answer: b
Clarification: He₂⁺ = 0.5, H₂, Li₂, B₂, HF, HCl = 1, NO = 2.5, CO = 3.

10. The interaction between a pair of orbitals of the same type is _________
a) Attractive
b) Repulsive
c) There is no interaction
d) None of the mentioned
Answer: b
Clarification: The interaction between pair of orbitals of the same type is repulsive like between σ_2s and σ_2p orbitals.

Engineering Chemistry Multiple Choice Questions on “Distillation”.

1. The process of heating a liquid mixture to form vapours and then cooling the vapours to get pure component is called ____________
a) Crystallisation
b) Distillation
c) Chromatography
d) Sublimation
Answer: b
Clarification: The process of heating a liquid mixture to form vapours and then cooling the vapours to get pure component is called distillation. Distillation is a process of separating the component substances from a liquid mixture by selective evaporation and condensation.

2. Porcelain pieces are put into the distillation flask to avoid ____________
a) Overheating
b) Uniform boiling
c) Bumping of the solution
d) None of the mentioned options
Answer: c
Clarification: Porcelain pieces are put into the distillation flask to avoid bumping of the solution due to uneven heating.

3. The boiling point of chloroform is ____________
a) 334 K
b) 286 K
c) 350 K
d) 298 K
Answer: a
Clarification: The boiling point of chloroform is 334 K. Chloroform is an organic compound with formula CHCl₃. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE and refrigerants.

4. The boiling point of aniline is ____________
a) 438 K
b) 370 K
c) 338 K
d) 457 K
Answer: d
Clarification: The boiling point of aniline is 457 K. Aniline is a toxic organic compound with the formula C₆H₅NH₂.

5. How aniline and chloroform can be separated?
a) Sublimation
b) Condensation
c) Distillation
d) Evaporation
Answer: c
Clarification: Aniline and chloroform can be separated through the distillation process. Aniline is a toxic organic compound with the formula C₆H₅NH₂. Chloroform is an organic compound with formula CHCl₃. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE and refrigerants.

6. Which of the following is not separated through distillation process?
a) Acetone and water
b) Aniline and chloroform
c) Impurities in Sea water
d) Milk and water
Answer: d
Clarification: Milk and water are not separated through the distillation process. All the other options can be separated through a distillation process.

7. Which of the following will vaporize faster?
a) Aniline
b) Chloroform
c) Water
d) Kerosene
Answer: b
Clarification: Chloroform will vaporize faster than aniline and water. Chloroform is an organic compound with formula CHCl₃. It is a colorless, sweet-smelling, dense liquid that is produced on a large scale as a precursor to PTFE and refrigerants.

8. The distilled water is collected in ____________
a) Receiver
b) Adapter
c) Condenser
d) Round bottom flask
Answer: a
Clarification: The distilled water is collected in the receiver. An installation for distillation, especially of alcohol, is a distillery. The distillation equipment is still.

9. The process of distillation is used for the liquids having ____________
a) Sufficient difference in their boiling point
b) Sufficient difference in their melting point
c) Sufficient difference in their solubility
d) None of the mentioned
Answer: a
Clarification: The process of distillation is used for the liquids having a sufficient difference in their boiling point. Distillation also permits the separation of air into its components.

10. The residue in the round bottom flask is ____________
a) Volatile
b) Non volatile
c) None of the mentioned
d) Volatile & Non volatile
Answer: b
Clarification: The residue salt int he round bottom flask is non volatile in nature. The process of distillation is used for the liquids having a sufficient difference in their boiling point. Distillation also permits the separation of air into its components.

Engineering Chemistry Online test focuses on “Vibrational Spectroscopy”.

1. Vibrational spectroscopy involves the transitions falling in the spectral range of ____________
a) 100-1000 cm^-1
b) 300-3000 cm^-1
c) 400-4000 cm^-1
d) 500-5000 cm^-1
Answer: c
Clarification: Vibrational spectroscopy involves the transitions falling in the spectral range of 400-4000 cm^-1 (infrared region).

2. Which of the region of IR spectra appears between (1400-600) cm^-1?
a) Functional group region
b) Fingerprint region
c) Low-frequency region
d) None of the mentioned
Answer: b
Clarification: Fingerprint region of IR spectra appears between (1400-600) cm^-1.

3. Select the correct statement from the following option.
a) Infrared spectra can identify the unknown materials
b) It can determine the amount of components in a mixture
c) It can also determine the quality of a sample
d) All of the mentioned
Answer: d
Clarification: Infrared spectra can identify the unknown materials. It can determine the amount of components in a mixture and can also determine the quality of a sample.

4. Which of the following molecule have infrared active vibrations?
a) NO
b) CH₄
c) H₂
d) All of the mentioned
Answer: a
Clarification: NO molecule have infrared active vibrations. Infrared spectra can identify unknown materials. It can determine the amount of components in a mixture and can also determine the quality of a sample.

5. Which of the following cannot show a vibrational absorption spectrum?
a) OCS
b) H₂O
c) CO₂
d) C H₂ = C H₂
Answer: d
Clarification: C H₂ = C H₂ cannot show vibrational absorption spectrum. OCS, H₂O and CO₂ can show a vibrational absorption spectrum.

6. Which of the following is not a type of bending molecular vibration?
a) Twisting
b) Stretching
c) Wagging
d) Rocking
Answer: b
Clarification: Stretching is not a type of bending molecular vibration. Twisting, wagging and rocking are types of bending molecular vibration.

7. What is the absorption frequency(cm^-1) of –C=N functional group?
a) 3610-3640
b) 1690-1760
c) 1180-1360
d) 2850-2960
Answer: c
Clarification: The absorption frequency for –C=N group is 1180-1360 cm^-1. Absorption spectroscopy refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample.

8. Presence of a functional group in a compound can be established by using _____________
a) Chromatography
b) IR spectroscopy
c) Mass spectroscopy
d) X-ray diffraction
Answer: b
Clarification: Presence of a functional group in a compound can be established by using IR spectroscopy. It is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light.

9. Select the incorrect option from the following option.
a) IR spectroscopy helps in the determination of purity
b) IR spectroscopy helps in the determination of force constant from vibrational spectrum
c) IR spectroscopy helps in identifying an unknown compound
d) None of the mentioned
Answer: d
Clarification: All the options are correct. IR spectroscopy helps in the determination of purity, force constant from the vibrational spectrum and identifying an unknown compound.

10. IR spectroscopy helps in detecting the presence of hydrogen bonding.
a) True
b) False
Answer: a
Clarification: IR spectroscopy helps in detecting the presence of hydrogen bonding. It is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light.

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