Category: Engineering Chemistry Objective Questions

Engineering Chemistry Multiple Choice Questions on “Conformations”.

1. Conformations are different arrangements of atoms that can be converted into one another by rotation about ___________
a) Covalent bond
b) Double bond
c) Single bond
d) Triple bond
Answer: c
Clarification: Conformational isomerism is a form of stereoisomerism in which the isomers can be interconverted exclusively by rotations about formally single bonds. Such isomers are generally referred to as conformational isomers or conformers and, specifically, as rotamers.

2. The energy required to rotate n-butane molecule about the carbon-carbon bond is called ___________
a) Rotational energy
b) Torsional energy
c) Enantiomeric energy
d) Potential energy
Answer: b
Clarification: The energy required to rotate n-butane molecule about the carbon-carbon bond is called torsional energy. Torsion energy can be used to solve problems of general relativity especially the singularity problem.

3. The rotation about the (C₂ – C₃) carbon-carbon bond of n-butane requires the energy of about ___________
a) 100 kJ/mol
b) 50 kJ/mol
c) 10 kJ/mol
d) 3 kJ/mol
Answer: d
Clarification: The rotation about the (C₂ – C₃) carbon-carbon bond of n-butane requires the very less energy of about 3kJ/mol. It requires very less amount of energy.

4. The infinity of intermediate conformations are called ___________
a) Skew conformations
b) Staggered conformations
c) Eclipsed conformations
d) Gauche
Answer: a
Clarification: The infinity of intermediate conformations are called skew conformations. Three conformations of cyclohexane, designated as chair, boat, and skew (or twist), are essentially free of angle strain.

5. The potential energy of n-butane is minimum for ___________
a) Skew conformations
b) Staggered conformations
c) Eclipsed conformations
d) Gauche
Answer: b
Clarification: The potential energy of n-butane is minimum for staggered conformations. It is because of no steric hindrance.

6. The potential energy of n-butane is maximum for ___________
a) Skew conformations
b) Staggered conformations
c) Eclipsed conformations
d) Gauche
Answer: c
Clarification: The potential energy of n-butane is maximum for eclipsed conformations. It is because of overlapping of functional groups.

7. The relative instability of any of the intermediate skew conformations is due to ___________
a) Lateral strain
b) Shear strain
c) Longitudinal strain
d) Torsional strain
Answer: d
Clarification: The relative instability of any of the intermediate skew conformations is due to torsional strain. Torsion energy can be used to solve problems of general relativity especially the singularity problem.

8. In gauche conformations, the methyl groups are ___________
a) 60⁰ apart
b) 90⁰ apart
c) 180⁰ apart
d) 360⁰ apart
Answer: a
Clarification: In gauche conformations, the methyl groups are 60⁰ apart. In general a gauche rotamer is less stable than an anti-rotamer.

9. Both anti and gauche conformations are free of torsional strain.
a) True
b) False
Answer: a
Clarification: Both anti and gauche conformations are free of torsional strain. In general, a gauche rotamer is less stable than an anti-rotamer.

10. Gauche conformation is less stable due to _______________
a) Hydrogen bonding
b) Covalent bonding
c) Vander Waal’s repulsion
d) Torsional strain
Answer: c
Clarification: Gauche conformation is less stable due to Vander Waal’s repulsion. Vander Waal’s are weak forces of attraction which results in lesser stability of gauche conformer.

11. Which of the following is least stable?
a) Anti conformation
b) Gauche conformation
c) Staggered conformation
d) Eclipsed conformation
Answer: d
Clarification: Eclipsed conformation is the least stable due to its high torsional energy. The potential energy of n-butane is maximum for eclipsed conformations.

12. Potential energy remains same during the rotation about the carbon-carbon of n-butane.
a) True
b) False
Answer: b
Clarification: Potential energy changes during the rotation about the carbon-carbon of n-butane. The potential energy of n-butane is maximum for eclipsed conformations and minimum for staggered conformations.

Engineering Chemistry Multiple Choice Questions on “Chromatography Applications”.

1. What are the uses of partition chromatography?
a) Separation of amino acids
b) Analysis of closely related aliphatic alcohols
c) Separation of sugar derivatives
d) All of the mentioned
Answer: d
Clarification: The uses of partition chromatography are separation of amino acids, analysis of closely related aliphatic alcohols and separation of sugar derivatives.

2. Which type of chromatography is used for the structural analysis?
a) Column chromatography
b) Paper chromatography
c) Partition chromatography
d) Affinity chromatography
Answer: b
Clarification: Paper chromatography is used for structural analysis. Paper chromatography is an analytical method that is used to separate colored chemicals or substances.

3. Which of the following is not done using column chromatography?
a) The identification of unknown compounds
b) The determination of homogeneity of chemical substances
c) Separation of inorganic cations or complexes
d) Separation of geometric isomers
Answer: c
Clarification: Separation of inorganic cations or complexes is done using paper chromatography. Column chromatography is a method used to purify individual chemical compounds from mixtures of compounds.

4. Affinity chromatography is used for the analysis and isolation of ____________
a) Insoluble starch substances
b) Enzyme tyrosinase
c) Antibodies bound with a covalently-attached antigen on cellulose column
d) All of the mentioned
Answer: d
Clarification: Affinity chromatography is used for the analysis and isolation of insoluble starch substances, enzyme tyrosinase and antibodies bound with a covalently-attached antigen on cellulose column.

5. Purification of enzymes and proteins is done using ____________
a) Affinity chromatography
b) Liquid chromatography
c) Column chromatography
d) Thin layer chromatography
Answer: a
Clarification: Affinity chromatography is used for the purification of enzymes and proteins. Affinity chromatography is also used for the analysis and isolation of insoluble starch substances, enzyme tyrosinase and antibodies bound with a covalently-attached antigen on cellulose column.

6. Which of the following is not an application of high performance liquid chromatography?
a) Analysis of proteins, drugs and explosives
b) Separation of pharmaceutical drugs
c) Elimination of undesirable substances from blood
d) Separation of lipids, fatty acids and steroids
Answer: c
Clarification: Elimination of undesirable substances from blood is done using affinity chromatography. All the other options are the application of high performance liquid chromatography.

7. The checking of purity of samples is the application of thin layer chromatography.
a) True
b) False
Answer: a
Clarification: The checking of purity of samples is the application of thin layer chromatography. It is a chromatography technique used to separate non-volatile mixtures.

8. The analysis and separation of industrial products like soap and synthetic detergents is done using ____________
a) Thin layer chromatography
b) Gas chromatography
c) Ion exchange chromatography
d) Partition chromatography
Answer: b
Clarification: The analysis and separation of industrial products like soap and synthetic detergents is done using gas chromatography. It is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition.

9. Which of the following is the application of ion exchange chromatography?
a) The softening of hard water
b) The demineralisation of water
c) The separation and determination of anions
d) All of the mentioned
Answer: d
Clarification: The application of ion exchange chromatography is softening of hard water, demineralisation of water and the separation and determination of anions.

10. The quantitative analysis is done using ____________
a) Ion exchange chromatography
b) Thin layer chromatography
c) Gas chromatography
d) Liquid chromatography
Answer: c
Clarification: Gas chromatography is used for the quantitative analysis. It is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition.

Engineering Chemistry Multiple Choice Questions & Answers focuses on “Fission of Covalent Bond”.

1. A covalent bond between two atoms may be broken in different ways depending upon __________
a) Nature of given organic compound
b) Nature of attacking reagent
c) Reaction conditions
d) All of the mentioned
Answer: d
Clarification: A covalent bond between two atoms may be broken in different ways depending upon nature of given organic compound, nature of attacking reagent and reaction conditions.

2. Select the incorrect statement from the following option.
a) Fission of covalent bond leads to the generation of intermediate organic species
b) They are stable and long-lived
c) The presence of reactive intermediates is confirmed by their detection by spectroscopic methods
d) None of the mentioned
Answer: b
Clarification: The intermediate species are unstable and short-lived. All the other options are correct. Fission of covalent bond leads to the generation of intermediate organic species. The presence of reactive intermediates is confirmed by their detection by spectroscopic methods.

3. The breaking of a covalent bond in such a way that each atom separates with one electron of the shared pair is called __________
a) Homolytic fission
b) Heterolytic fission
c) Monolytic fission
d) Morpholytic fission
Answer: a
Clarification: The breaking of a covalent bond in such a way that each atom separates with one electron of the shared pair is called homolytic fission. Homo refers to same and in this fission every atom has same number of electrons.

4. The breaking of a covalent bond in such a way that both the electrons of shared pair are carried away by one of atom is called __________
a) Morpholytic fission
b) Monolytic fission
c) Heterolytic fission
d) Homolytic fission
Answer: c
Clarification: The breaking of a covalent bond in such a way that both the electrons of shared pair are carried away by one of atom is called heterolytic fission. Hetero refers to different and in this fission every atom has different number of electrons.

5. Heterolytic fission takes place between two atoms of widely different __________
a) Conductivity
b) Viscosity
c) Electronegtivity
d) All of the mentioned
Answer: c
Clarification: Heterolytic fission takes place between two atoms of widely different electronegativity. The more electronegative atom will not attract the electron as compared to less electronegative atom.

6. Select the incorrect statement from the following option.
a) Heterolytic fission takes place generally in a polar solvent
b) Heterolytic fission takes place usually at higher temperatures
c) Cations and anions formed are generally carbon-based
d) None of the mentioned
Answer: b
Clarification: Heterolytic fission takes place usually at lower temperatures. All the other options are correct. Heterolytic fission takes place generally in a polar solvent and cations and anions formed are generally carbon-based.

7. Which of the following is intermediate organic species based on carbon formed by homolytic fission?
a) Carbenes
b) Carbo-cations
c) Carbanions
d) Free radicals
Answer: d
Clarification: Free radicals are intermediate organic species based on carbon formed by homolytic fission. Free radicals are different from cations and anions. They do not carry any charge with them.

8. Which of the following is intermediate organic species based on carbon formed by photolysis?
a) Carbenes
b) Carbo-cations
c) Carbanions
d) Free radicals
Answer: a
Clarification: Carbenes are intermediate organic species based on carbon formed by photolysis. A carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons.

9. Triplet carbene is more stable than singlet carbene.
a) True
b) False
Answer: a
Clarification: Triplet carbene is more stable than singlet carbene. A carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons.

10. The shape of carbanion is __________
a) Linear
b) Trigonal planar
c) Pyramidal
d) Bent
Answer: c
Clarification: The shape of carbanion is pyramidal. A carbanion is an anion in which carbon has an unshared pair of electrons and bears a negative charge usually with three substituents for a total of eight valence electrons.

To practice all areas of Engineering Chemistry,

Engineering Chemistry Multiple Choice Questions on “One Component System”.

1. With respect to one component system, what is the mixture present at the triple point?
a) Water
b) Ice
c) Water vapor
d) Water, ice, vapor
Answer: d
Clarification: Since at the triple point, all the states of water are in equilibrium, all the three states will stay together. At this point where the three phases exist is invariant where F=0.

2. Which of the following statements is incorrect about the triple point?
a) The point at which the solid, liquid and gaseous phases for a substance co-exist
b) The triple point exists for a substance at a specific temperature and pressure
c) The triple point exists at a single temperature and is not related with pressure
d) The system must be closed so that no vapor can escape
Answer: c
Clarification: The triple point for a pure substance occurs in a closed system at a particular temperature and pressure (i.e. one cannot be varied with the other). Hence the triple point is dependent on both the factors.

3. What does a horizontal arrest in a cooling system refer to?
a) Continuous cooling
b) Invariant reaction
c) Variant reaction
d) Bi variant reaction
Answer: b
Clarification: Horizontal arrest refers to the equilibrium state of the system where the degree of freedom is 0 (as all the phases co-exist) and hence this state is referred to as invariant reaction (unique point).

4. Calculate the degree of freedom for sublimation curve.
a) Does not exist
b) 1
c) 0
d) 2
Answer a
Clarification: Since in the sublimation curve, super cooled liquid exists along with Vapor and liquid states, this condition will not be applicable to normal Gibbs formula which states F = C-P+2.

5. Calculate the number of phases at the sublimation curve.
a) 2
b) 3
c) 4
d) 0
Answer: c
Clarification: Since in a sublimation state, all the phases exist together (solid, liquid, vapor and super cooled liquid), they contribute to individual species and hence the number of phases is four.

6. Under what condition is one component system converted to two component systems?
a) Decrease the temperature
b) Add a miscible liquid
c) Add an immiscible liquid
d) Decrease the pressure
Answer: b
Clarification: We know that two immiscible liquids form a heterogeneous mixture. Similarly, if a miscible liquid is added to the one component system, then under high temperature and pressure, it can be converted into two component systems.

7. Under what condition is two component systems converted to one component system?
a) Decrease the temperature
b) Add a miscible liquid
c) Add an immiscible liquid
d) Decrease the pressure
Answer: c
Clarification: We know that two miscible liquids form a homogeneous mixture. Similarly, if an immiscible liquid is added to the two component systems, then under high temperature and pressure, it can be converted into one component system.

8. Calculate the degree of freedom for the following reaction.
CH₄ ⟶ CO₂ (gas) + 2H₂0
a) 2
b) 3
c) 4
d) 6
Answer: a
Clarification: The number of components in this system is three. Also the number of phase in this reaction is three. Therefore the degree of freedom is given by F = C-P+2. Therefore F=2.

9. Calculate the degree of freedom for decomposition of potassium permanganate.
a) 3
b) 2
c) 1
d) 0
Answer: b
Clarification: In this reaction, the number of phases is 3 (solid, liquid, gas). The number of components is also 3. Therefore the degree of freedom is given by F = C-P+2. Therefore F=2.

10. Calculate the degree of freedom for decomposition of charcoal.
a) 1
b) 2
c) 3
d) 0
Answer: c
Clarification: In this reaction, the number of phases is 2 and the number of components is 3. Hence the degree of freedom is given by F=C-P+2. Therefore here the degree of freedom is F=3-2+2=3.

Engineering Chemistry Multiple Choice Questions on “Thermosetting Polymers”.

1. The neighbouring polymeric chains in thermosets are held together by ____________
a) Vander Waal’s force
b) Hydrogen bond
c) Covalent bond
d) Electrovalent bond
Answer: c
Clarification: The neighbouring polymeric chains in thermosets are held together by covalent bonds. A covalent bond is bond by the sharing of electrons and has good strength.

2. Select the incorrect statement from the following option.
a) Thermosets have 3-dimensional, cross-linked network structure
b) Thermosets cannot be remoulded, reused or reclaimed
c) Thermosets are hard, strong and brittle
d) Thermosets are soluble in suitable solvents
Answer: d
Clarification: Thermosets are insoluble in any solvent. They have a 3-D cross-linked network structure and cannot be remoulded, reused or reclaimed. They are hard, strong and brittle.

3. Which of the following is not an example of thermosets?
a) Epoxy
b) Teflon
c) Vulcanised rubber
d) Bakelite
Answer: b
Clarification: Epoxy, vulcanised rubber, Bakelite are some of the examples of thermosets. Teflon is not an example of thermosets. PTFE (Teflon) is best known for its use in coating non-stick frying pans and other cookware.

4. The condensation product of phenol and formaldehyde is known as _________
a) Phenolic resins
b) Urea formaldehyde resins
c) Polyvinyl chloride
d) Polystyrene
Answer: a
Clarification: The condensation product of phenol and formaldehyde is known as phenolic resins or phenoplasts or PF resins. Phenoplasts include the expanded plastics obtained by introducing a blowing agent (foaming agent).

5. Which of the following condition is not true for the formation of Bakelite?
a) Excess of phenol
b) Excess of formaldehyde
c) Acid catalyst
d) Heat and curing agent
Answer: b
Clarification: Excess of formaldehyde is not required for the formation of Bakelite. Excess of phenol is required in the formation of Bakelite and it also requires an acid catalyst and heat and curing agent.

6. Which of the following condition is not true for the formation of Resite?
a) Excess of formaldehyde
b) Base catalyst
c) Acid catalyst
d) Neutral or acidic conditions and heat
Answer: c
Clarification: Acid catalyst is not used for the formation of the Resite. It requires a base catalyst and excess of formaldehyde. It also requires neutral or acidic conditions of heat.

7. Select the incorrect statement from the following option.
a) Phenolic resins are hard, rigid and strong
b) Phenolic resins have good abrasion resistance
c) Phenolic resins are usually dark coloured, pinkish brown
d) Phenolic resins have poor chemical resistance
Answer: d
Clarification: Phenolic resins have good chemical resistance. All the other options are correct. Phenolic resins are hard, rigid and strong and have good abrasion resistance. They are usually dark coloured, pinkish brown.

8. Which of the following is not an application of phenolic resins?
a) Finishing of cotton textiles
b) Distributor heads of car
c) Domestic plugs and switches
d) Adhesives for grinding wheels
Answer: a
Clarification: Distributor heads of car, domestic plugs and switches, adhesives for grinding wheels, etc are some of the applications of phenolic resins. It also includes the expanded plastics obtained by introducing a blowing agent (foaming agent).

9. Urea formaldehyde resins are used as adhesives for plywood and furniture.
a) True
b) False
Answer: a
Clarification: Urea formaldehyde resins are used as adhesives for plywood and furniture. These resins are used in adhesives, finishes, particle board, MDF, and molded objects. UF and related amino resins are considered a class of thermosetting resins of which urea-formaldehyde resins make up 80% produced globally.

10. Select the incorrect statement about the Urea formaldehyde resins from the following option.
a) They are clear and colorless
b) They have good adhesive characteristics
c) They have low hardness and tensile strength than PF resins
d) They have excellent abrasion resistance
Answer: c
Clarification: Urea formaldehyde resins have a better hardness and tensile strength than PF resins. All the other options are correct. They are colorless, clear and have good adhesive characteristics and excellent abrasion resistance.

Engineering Chemistry Question Paper focuses on “Determination of Calorific Value of Solid and Non-Volatile Liquid Fuels – 2”.

1. To calculate the calorific value of coal using bomb’s calorimeter, which of the following compound are formed after the bomb is removed from the calorimeter?
a) H₂S and CO₂
b) H₂SO₄ and HNO₃
c) H₂SO₄ and NO₂
d) SO₂ and HNO₃
Answer: b
Clarification: Since the vapours of H₂SO₄ and HNO₃ are formed during combustion of coal, that is why at last the amounts of H₂SO₄ and HNO₃ are calculated to find the gross calorific value of the coal.

2. Which of the following correction of bomb calorimeter is added to the observed raise in temperature?
a) Acid correction
b) Fuse wire correction
c) Cotton thread correction
d) Cooling correction
Answer: d
Clarification: Cooling correction is the product of time taken for the calorimeter to cool(x) and the rate of cooling (dt),
Cooling correction (t_c) = x.dt

3. On what basis does the acid correction is measured in bomb calorimeter?
a) Gases present in the bomb
b) Due to formation of the compound after adding water in the bomb
c) Due to the presence of excess oxygen
d) Due to the material of the bomb
Answer: b
Clarification: When water is added to the bomb, the gases present in it forms acid, due to which some heat is liberated which is not obtainable in practical use, thus this heat liberated has to be deducted from the value so as to get the exact value of GCV.

4. How is the heat liberated in fuse wire correction?
a) By the breakage of fuse wire
b) Due to the material of fuse wire
c) Due to the ignition of fuse wire
d) Due to the length of fuse wire
Answer: c
Clarification: When an electric current passes through the fuse wire, there is some heat liberated which is of no use of the bomb, so it has to be subtracted from the final value.

5. For which of the following correction we should use a larger sample mass?
a) Fuse wire correction
b) Cotton thread correction
c) Cooling correction
d) Acid correction
Answer: b
Clarification: This is because the cotton thread correction obtained is very small, due to which for small masses its value is negligible, therefore for calculating these corrections we should use larger mass sample.

6. In a bomb calorimeter experiment, following data was obtained: x = 0.85gm, W = 2.5kg, w = .5kg, observed rise in temperature = 2.25 ⁰C, t_A = 38.6 calories, t_F = 6.8 calories, t_T = 1.9 calories and t_C = 0.05 ⁰C. Calculate net calorific value if the coal contains 10 % hydrogen?
a) 7533.7 cal/gm
b) 5704.655 cal/gm
c) 8062 cal/gm
d) 8.062 cal/gm
Answer: a
Clarification: From the formulae,
GCV = [(W+w){(T₂ – T₁) + t_c} – (t_A + t_F + t_T)]/x
GCV = 8062 cal/gm
NCV = GCV – (0.09×587×%H)
NCV = 7533.7 cal/gm.

7. Which of the following correction are obtained in the largest amount in bomb calorimeter?
a) Fuse wire correction
b) Acid correction
c) Cotton thread correction
d) Cooling correction
Answer: b
Clarification: This is because the amount of heat liberated during the analysis if acid correction is maximum, which is why it has the largest value.

8. The correct cotton thread used for firing the charge is calculated from the weight of wet cotton thread.
a) True
b) False
Answer: b
Clarification: Dry cotton thread is used in calculating the calorific value of fuel in a bomb calorimeter.

9. Determine the water equivalent of the bomb calorimeter apparatus which gave following data during experiment: Weight of benzoic acid taken = 2.12 gm, Weight of water taken in calorimeter = 2.5kg, Initial temperature= 16.970, Final temperature = 18.650, Cooling correction = 0.035 ⁰C, fuse wire correction = 20 calories and cotton thread correction = 2.2 calories? (Calorific value of benzoic acid=6324)
a) 7253.22 gm
b) 8366.50 gm
c) 7830.36 gm
d) 5330.36 gm
Answer: d
Clarification: Heat evolved by benzoic acid = 13406.88 calories
Total amount of heat given to calorimeter = 13429.08 calories
Corrected rise in temperature = 1.715 ⁰C
Total water equivalent = 13429.08/1.715 = 7830.36 gm
Water equivalent of calorimeter = 5330.36 gm.

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