Category: Engineering Chemistry Objective Questions

Engineering Chemistry Questions and Answers for Aptitude test focuses on “Chirality”.

1. Chiral molecules are those which are?
a) Shows geometrical isomerism
b) Superimposable on their mirror images
c) Not superimposable on their mirror images
d) Unstable molecules
Answer: c
Clarification: Chiral molecules are those which are not superimposable on their mirror images. The presence of an asymmetric carbon atom is one of several structural features that induce chirality in organic and inorganic molecules.

2. Which of the following is not an example of chiral object?
a) Cylindrical helix
b) Square box
c) Sandal or shoe
d) Glove
Answer: b
Clarification: A square box is not chiral as it gives super-imposable mirror image. All the other mentioned options does not give the super-imposable mirror images.

3. For any given substance, the amount of rotation does not depends upon _________
a) Wavelength of light used
b) Nature of the solvent
c) Temperature
d) Pressure
Answer: d
Clarification: For any given substance, the amount of rotation depends upon the concentration, nature of solvent, temperature, length of layer traversed and the wavelength of light used. It does not depend upon the pressure conditions.

4. If the rotation of the plane is clockwise, the substance is dextrorotatary.
a) True
b) False
Answer: a
Clarification: If the rotation of the plane is clockwise, the substance is dextro rotatary. And if the rotation of the plane is anti-clockwise, the substance is leavo rotatary.

5. The specific rotation is inversely proportional to _________
a) Observed rotation
b) Temperature
c) Concentration of solution
d) D-line of sodium vapour light
Answer: c
Clarification: The specific rotation is inversely proportional to the concentration of solution and length of sample tube.

6. 0.5 g of an optically active compound was dissolved in 2mL of solvent at 25⁰C. The solution was kept in a cell of length 10 cm and observed rotation was +10⁰. What is the specific rotation of its enantiomer?
a) -40⁰
b) +40⁰
c) -10⁰
d) +10⁰
Answer: b
Clarification: [α] = α/lC = +10⁰/(1*0.5/2) = +40⁰.

7. To avoid excessive high value of molecular rotation, concentration is taken as _________
a) 1 centi-mole/mL
b) 1 milli-mole/mL
c) 1 mole/mL
d) 1 kilo-mole/mL
Answer: a
Clarification: To avoid excessive high value of molecular rotation, concentration is taken as 1 centi-mole/mL.

8. Chiral molecules which are non-super-imposable mirror images of each other are called _________
a) Diastereomers
b) Meso compounds
c) Racemic mixture
d) Enantiomers
Answer: d
Clarification: Chiral molecules which are non-superimposable mirror images of each other are called enantiomers. Enantiomer members often have different chemical reactions with other enantiomer substances.

9. Select the correct statement from the following option.
a) Enantiomer rotate plane of polarised light in opposite direction and to different extent
b) Enantiomer rotate plane of polarised light in same direction but to different extent
c) Enantiomer rotate plane of polarised light in same direction and to same extent
d) Enantiomer rotate plane of polarised light in opposite direction but to same extent
Answer: d
Clarification: Enantiomer rotate plane of polarised light in opposite direction but to same extent. Enantiomer members often have different chemical reactions with other enantiomer substances.

10. Enantiomerism is the phenomenon of existence of enantiomers in a single structural formula, in _________ configuration.
a) Same
b) Opposite
c) Same as well as opposite
d) Initially opposite and then same
Answer: b
Clarification: Enantiomerism is the phenomenon of existence of enantiomers in a single structural formula but in opposite configuration.

11. Select the incorrect statement from the following option.
a) The physical properties of enatiomers are identical
b) In symmetrical environment, the chemical properties of enantiomers are identical
c) The enantiomers react at same rate and form products in same amounts in assymetrical environment
d) Enantiomers have different solubilities in the same chiral solvent
Answer: c
Clarification: The enantiomers react at different rate and form products in different amounts in assymetrical environment. All the other options are correct.

12. Optical activity can also result from the lack of molecular symmetry in molecules.
a) True
b) False
Answer: a
Clarification: Optical activity can also result from the lack of molecular symmetry in molecules which do not have chiral carbon.

13. The plane which divides the molecule into two equal parts so that each half is the mirror image of other half is called _________
a) Centre of symmetry
b) Plane of symmetry
c) Axis of symmetry
d) Angle of symmetry
Answer: b
Clarification: The plane divides the molecule into two equal parts so that each half is the mirror image of other half is called plane of symmetry. Centre of symmetry is the central point about which the molecule is symmetrical.

14. When a molecule has a plane of symmetry, it will be ______________
a) Optically inactive
b) Optically active
c) Both optically active & inactive
d) Enantiomer
Answer: a
Clarification: When a molecule has a plane of symmetry, it will be optically inactive, even though it might contain chiral carbon.

15. A centre of symmetry is equivalent to _________ fold alternating axis of symmetry.
a) One
b) Two
c) Three
d) Four
Answer: b
Clarification: A centre of symmetry is equivalent to two-fold alternating axis of symmetry.

16. Diastereomers are _________
a) Geometrical isomers
b) Mirror images
c) Non-mirror images
d) Unstable molecules
Answer: c
Clarification: Diastereomers are not mirror images of each other. Diastereomerism occurs when two or more stereo isomers of a compound have different configurations at one or more of the equivalent stereo centers and are not mirror images of each other.

17. A plane of symmetry is equivalent to _________ fold alternating axis of symmetry.
a) One
b) Two
c) Three
d) Four
Answer: a
Clarification: A centre of symmetry is equivalent to one-fold alternating axis of symmetry.

18. As the optical activity changes with the wavelength of light, it is necessary not to use monochromatic light to measure optical activity.
a) True
b) False
Answer: b
Clarification: As the optical activity changes with the wavelength of light, it is necessary to use monochromatic light to measure optical activity.

areas of Engineering Chemistry for Aptitude test,

Engineering Chemistry Multiple Choice Questions on “Chromatography”.

1. Chromatography is the process for identification, purification and separation of components of a mixture on the basis of ____________
a) Difference in their boiling point
b) Difference in their melting point
c) Difference in their affinity for mobile and stationary phase
d) Difference in their solubility
Answer: c
Clarification: Chromatography is the process for identification, purification and separation of components of a mixture on the basis of difference in their affinity for mobile and stationary phases. The mixture is dissolved in a fluid called the mobile phase, which carries it through a structure holding another material called the stationary phase.

2. Chromatography involves two mutually ____________
a) Immiscible phases
b) Miscible phases
c) Soluble phases
d) None of the mentioned
Answer: a
Clarification: Chromatography involves two mutually immiscible phases (stationary and mobile phases). The mixture is dissolved in a fluid called the mobile phase, which carries it through a structure holding another material called the stationary phase.

3. There is no need of support if packed into a column when the stationary phase is ____________
a) Gas
b) Liquid
c) Solid
d) None of the mentioned
Answer: c
Clarification: If the stationary phase is solid, there is no need of support if packed into a column. In solid phase, all the molecules are already in closed packing.

4. Which of the following is not a stationary phase?
a) Liquid-liquid chromatography
b) Gas-liquid chromatography
c) Gas-solid chromatography
d) Solid-solid chromatography
Answer: d
Clarification: Solid-solid chromatography is not a stationary phase because solid-solid phase cannot provide any fluidity.

5. Liquid chromatography is a technique for separating ____________
a) Ions that are not dissolved in a solvent
b) Ions that are dissolved in a solvent
c) Ions that are dissolved in a solute
d) All of the mentioned
Answer: b
Clarification: Liquid chromatography is a technique for separating ions that are dissolved in a solvent. Solute is the material which is dissolved and solvent is the solution in which it is dissolved.

6. In exclusion chromatography, solute molecules are separated based on ____________
a) Molecular geometry and size
b) Molecular composition
c) Molecular phase
d) Molecular formula
Answer: a
Clarification: In exclusion chromatography, solute molecules are separated based on molecular geometry and size. These two physical characteristics have a significance role in exclusion chromatography.

7. The gas-solid chromatography is ______________ chromatography as per basic principle involved.
a) Exclusion
b) Ion-exchange
c) Adsorption
d) Absorption
Answer: c
Clarification: The gas-solid chromatography is adsorption chromatography as per basic principle involved as the gas molecules are adsorbed on the solid surface.

8. A proper solvent that is passed through the column for elution so that separated components can be collected is called ____________
a) Adsorbent
b) Buffer solution
c) Mobile phase
d) None of the mentioned
Answer: b
Clarification: A proper solvent that is passed through the column for elution so that separated components can be collected is called buffer solution. The eluate is the mobile phase leaving the column. The eluent is the solvent that carries the analyte.

9. The relative solubility of solute in both the phases determines the ____________
a) Rate of movement of solvent
b) Rate of disappearance of solvent
c) Rate of movement of solute
d) Rate of disappearance of solute
Answer: c
Clarification: The relative solubility of solute in both the phases determines the rate of movement of solute as solute is added to the solution.

10. If the mobile phase is gas, movement of solute is determined by its ____________
a) Boiling point
b) Melting point
c) Solubility
d) Volatility
Answer: d
Clarification: If the mobile phase is gas, movement of solute is determined by its volatility because gas is always measured as volatility not as solubility or melting point or boiling point.

Engineering Chemistry Multiple Choice Questions on “Electromeric Effect”.

1. Which of the following is a temporary effect brought into play at the requirement of attacking reagent?
a) Inductive effect
b) Mesomeric effect
c) Electromeric effect
d) Inductomeric effect
Answer: c
Clarification: Electromeric effect is a temporary effect brought into play at the requirement of attacking reagent. Electromeric effect refers to a molecular polarizability effect occurring by an intra-molecular electron displacement.

2. Select the correct statement from the following option.
a) When multiple bonds are present between two different atoms, electromeric shift towards the more electronegative atom takes place
b) When multiple bonds are present between two similar atoms, the first possibility is symmetric alkenes or alkynes
c) When multiple bonds are present between two similar atoms, the second possibility is asymmetric alkenes or alkynes
d) All of the mentioned
Answer: d
Clarification: When multiple bonds are present between two different atoms, electromeric shift towards the more electronegative atom takes place. When multiple bonds are present between two similar atoms, the first possibility is symmetric alkenes or alkyne and the second possibility is asymmetric alkenes or alkynes.

3. Select the correct statement from the following option.
a) Conjugate effect is stronger than (-I) effect
b) Conjugate effect is weaker than (-I) effect
c) Conjugate effect is same as (-I) effect
d) None of the mentioned
Answer: a
Clarification: Conjugate effect is stronger than (-I) effect. Conjugate effect (or delocalization) is an effect in which molecular orbitals (MOs) are conjugated to new molecular orbitals that are more delocalized and therefore generally lower in energy.

4. When the complete transfer of π-electrons take place away from the atom at the requirement of attacking agent, it is called __________
a) (-E) effect
b) (+E) effect
c) (-I) effect
d) (+I) effect
Answer: b
Clarification: When the complete transfer of π-electrons takes place away from the atom at the requirement of attacking agent, it is called (+E) effect.

5. The positively charged and electron deficient compounds which have a tendency to form a bond by accepting the electron pair are known as __________
a) Electrophiles
b) Nucleophiles
c) Homophiles
d) All of the mentioned
Answer: a
Clarification: The positively charged and electron deficient compounds which have a tendency to form a bond by accepting the electron pair are known as electrophiles.

6. Which of the following is an example of lewis base?
a) ZnCl₂
b) BF₃
c) NH₃
d) FeCl₂
Answer: c
Clarification: NH₃ is an example of lewis base and ZnCl₂, BF₃ and FeCl₂ are the examples of lewis acid.

7. Which of the following is an incorrect statement about the nucleophiles?
a) They are electron rich
b) They possess an empty orbital to receive the electron pair
c) They attack electron deficient centres
d) Examples are: OH^–, NH₃, H₂O etc
Answer: b
Clarification: Nucleophiles possess an unshared electron pair which is not firmly held to the nucleus. All the other options are correct. They are electron rich and attack on electron deficient centres. Examples are: OH^–, NH₃, H₂O etc.

8. Lewis acids are examples of nucleophilic reagents.
a) True
b) False
Answer: b
Clarification: Lewis acids are the examples of electrophilic reagents and Lewis bases are the examples of nucleophilic reagents.

9. Those groups which are electron repelling and have lesser electron attracting power than hydrogen show __________
a) (+E) effect
b) (-E) effect
c) (-I) effect
d) (+I) effect
Answer: d
Clarification: Those groups which are electron repelling and have lesser electron attracting power than hydrogen show (+I) effect.

10. Which of the following molecule will show highest dipole moment?
a) CH₃Cl
b) CH₃Br
c) CH₃F
d) CH₃I
Answer: c
Clarification: CH₃F will show the highest dipole moment because it is the most electronegative compound.

Advanced Engineering Chemistry Questions and Answers focuses on “Application of Phase Rule to One Component System”.

1. Which of the following equilibriums can phase rule be applies to?
a) Isometric
b) Isobaric
c) Isometric and Isobaric
d) Mechanical
Answer: c
Clarification: Since phase rule can be applied to factors like solubility, concentration, reversibility of reaction, temperature, pressure, molecular weight, atomic weight, strength of molecules etc (since these parameters are applicable for isometric and isobaric states), phase rule can be applied to both isometric and isobaric equilibriums.

2. What kind of particles can phase rule be applied to?
a) Micro
b) Nano
c) Pico
d) Heavy particles
Answer: d
Clarification: Since the factors like solubility, concentration, reversibility of reaction, temperature, pressure, molecular weight, atomic weight, strength of molecules etc becomes negligible for microscopic particles, phase rule identifies only heavy particles.

3. What kind of behavior can phase rule identify?
a) Molecular behavior
b) Linear behavior
c) Curvic behavior
d) Atomic behavior
Answer: b
Clarification: In a general phase relation between temperature and concentration of the component of various systems, the general graph will show a proportionate relation between the two factors and hence phase rule identifies linear behavior.

4. For Gibbs free energy along a system path for a transformation from state 1 to state 2, the reaction kinetics can be expressed by __________
a) Rate = C exp(-ΔG1/RT)
b) Rate = C exp(-ΔG2/RT)
c) Rate = G/RT
d) Rate = RT/G
Answer: a
Clarification: In the above problem, we can see that the reactions coordinate increases as the energy increases up to certain point above equilibrium and then it gradually decreases. This system represents a system at stable point of time. Thus according to energy phase relation, the rate of reaction is Rate = C exp(-ΔG1/RT).

5. According to Gibbs phase rule for a 2-component system under condensed rule, what observation can be made within the equilibrium phase?
a) T can be varied independently
b) Varying a T value fixes the equilibrium compositions
c) Neither T nor concentration can be varied respectively
d) 2 phases cannot coexist
Answer: b
Clarification: During invariant position of the system (equilibrium state), sometimes due to increase in colligative properties of materials, the equilibrium faces a shift slightly. In this case, the equilibrium can be brought back by varying T values.

6. If the following conditions result in the formation of a regular solution?
a) Ω = 0
b) Ω > 0
c) Ω < 0
d) Ω = 10
Answer: c
Clarification: We know that as the resistance increases, conductance decreases. This happens at higher temperature and pressure. Thus a regular solution will be formed only when conductivity of the solution is high. Thus the required condition is Ω < 0.

7. With respect to the general phase diagram of two component system. Identify the type of solution formed at the eutectic point.
a) Regular solution
b) Steady state solution
c) Invariant solution
d) Transition solution
Answer: a
Clarification: From the general phase diagram, the concentration of the first component with respect to the other decreases till certain point (eutectic point) and then increases gradually such that the other component’s concentration increases together. Thus this is an example of regularity and hence a regular solution is obtained.

8. With respect to the phase diagram of copper zinc system. There happens a phase transition at a particular point. There happens an equilibrium shift consequently. At which point will zinc reach its maximum concentration?
a) Some point between transition and shift
b) After transition
c) Before shift
d) At the end of both transition and shift
Answer: d
Clarification: We know that all the transitions (equilibrium and phase transitions) take place within the range 200 to 400 which is the normal equilibrium range. According to Gibbs phase rule, zinc will reach its maximum concentration after equilibrium point that is at the eutectic point.

9. In the general phase diagram of water component system, the region that separates solid and liquid is called _______________
a) Fusion curve
b) Sublimation curve
c) Metastable curve
d) Critical curve
Answer: b
Clarification: In a water component system, sometimes the water may not undergo transition between solid to liquid instead directly gets converted from solid to vapor. This is a stable state where a small variation in composition or temperature may destroy the steadiness. This point is called sublimated curve.

10. During an experiment, a slight variation causes deposition of the component in its solid state. From the given data, calculate the amount of component deposited.
Temperature at equilibrium=0
Atmospheric temperature=217.7 k
Pressure=200 atm
a) 0.006
b) 0
c) 217.7
d) 100
Answer: b
Clarification: We know that according to Weiss law, concentration= temperature/pressure (this law suits only for phase components). In this problem, since the temperature corresponding to the deposition point is 0. Therefore, the concentration is zero which means that ideally, no deposition has taken place.

To practice advanced questions and answers on all areas of Engineering Chemistry,

Engineering Chemistry Multiple Choice Questions on “Polymerization”.

1. Which type of polymer will be formed if the substituent group is –C₆H₅?
a) Polythene
b) Polypropylene
c) Polystyrene
d) Polyvinyl chloride
Answer: c
Clarification: Polystyrene will be formed if the substituent group is –C₆H₅. It is a synthetic aromatic polymer made from the monomer styrene. Polystyrene can be solid or foamed.

2. Select the incorrect statement from the following option.
a) Addition polymerisation requires the presence of double bond in monomer
b) No by-product is formed in addition polymerisation
c) In addition polymerisation, growth of chain is at one active centre
d) In addition polymerisation, polymer MW rises steadily throughout the reaction
Answer: d
Clarification: In addition polymerisation, high MW polymer is formed at once. All the other options are correct. Addition polymerisation requires the presence of a double bond in monomer and no by-product is formed. In addition polymerisation, growth of chain is at one active centre.

3. Select the incorrect statement from the following option.
a) Condensation polymerisation requires two reactive functional groups to be present at both ends of the monomer
b) No by-product is formed in condensation polymerisation
c) In condensation polymerisation, growth of chain occurs at minimum of the two active centres
d) In condensation polymerisation, polymer MW rises steadily throughout the reaction
Answer: b
Clarification: Generally a by-product is formed in condensation polymerisation. All the other options are correct.
Condensation polymerisation requires two reactive functional groups to be present at both ends of the monomer and growth of chain occurs at a minimum of the two active centres. In condensation polymerisation, polymer MW rises steadily throughout the reaction.

4. The Ziegler Natta catalyst is formed between _____________
a) Triethyl aluminium and titanium halide
b) Triethyl aluminium and silver halide
c) Triethyl aluminium and platinum halide
d) Triethyl aluminium and carbon halide
Answer: a
Clarification: The Ziegler Natta catalyst is formed between triethyl aluminium and titanium halide. It is named after Karl Ziegler and Giulio Natta, used in the synthesis of polymers of 1-alkenes (alpha-olefins).

5. The co-polymers having branched structures in which the monomer segments on the backbone and branches differ are called ____________
a) Alternate
b) Graft
c) Random
d) Block
Answer: b
Clarification: The co-polymers having branched structures in which the monomer segments on the backbone and branches differ are called graft.

6. Which of the following act as an initiator in free-radical polymerisation?
a) Grignard reagent
b) Lewis acids
c) Benzoyl peroxide
d) Potassium amide
Answer: c
Clarification: Benzoyl peroxide act as an initiator in free-radical polymerisation. Benzoyl peroxide is used as an acne treatment, for bleaching flour, hair and teeth, for cross-linking polyester resins, and for many other purposes.

7. Which of the following act as a catalyst in anionic polymerisation?
a) Grignard reagent
b) Lewis acids
c) Benzoyl peroxide
d) AIBN
Answer: a
Clarification: Grignard reagent act as a catalyst in anionic polymerisation. The Grignard reaction is an organo-metallic chemical reaction in which alkyl, vinyl, or aryl-magnesium halides, CH₃MgI (Grignard reagents) add to a carbonyl group in an aldehyde or ketone.

8. The temperature at which the ionic polymerisation is carried out is ____________
a) 100⁰C
b) 50⁰C
c) -100⁰C
d) 0⁰C
Answer: d
Clarification: The temperature at which the ionic polymerisation is carried out is 0⁰C. Ionic polymerization is a chain-growth polymerization in which active centers are ions or ion pairs.

9. Radical polymerisation is not sensitive to changes in the polarity.
a) True
b) False
Answer: a
Clarification: Radical polymerisation is not sensitive to changes in the polarity. Free radical polymerization is a method of polymerization by which a polymer forms by the successive addition of free radical building blocks.

10. Which of the following monomer cannot be polymerised by radical polymerisation?
a) Butadiene
b) Isobutylene
c) Vinyl chloride
d) Acrylates
Answer: b
Clarification: Isobutylene monomer can be polymerised by cationic polymerisation. Butadiene, vinyl chloride and acrylates can be polymerised by radical polymerization.

11. The polymerisation in which propagating centers do not undergo either transfer or termination reactions is called ____________
a) Addition polymerisation
b) Co-polymerisation
c) Living polymerisation
d) Dead polymerisation
Answer: c
Clarification: The polymerisation in which propagating centers do not undergo either transfer or termination reactions is called living polymerisation. Polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.

12. In esterification, the nucleophile is _________ and the leaving group is ____________
a) Alcohol, ester
b) Ester, alcohol
c) Water, alcohol
d) Alcohol, water
Answer: d
Clarification: In esterification, the nucleophile is alcohol and the leaving group is water. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product.

13. The reverse of esterification is ____________
a) Hydrolysis
b) Condensation
c) Polymerisation
d) Centrifugation
Answer: a
Clarification: The reverse of esterification is hydrolysis. Hydrolysis is a reaction involving the breaking of a bond in a molecule using water. The reaction mainly occurs between an ion and water molecules and often changes the pH of a solution.

14. Which of the following is used for making cold drink bottles, magnetic recording tapes and housings for coffee machines?
a) Ethylene glycol
b) Polyethylene terephthalate
c) Hexamethylene diamine
d) Styrene butadiene
Answer: b
Clarification: Polyethylene terephthalate (PET) is used for making cold drink bottles, magnetic recording tapes and housings for coffee machines. PET consists of polymerized units of the monomer ethylene terephthalate, with repeating (C₁₀H₈O₄) units and is commonly recycled.

15. Terephthalic acid and ethylene glycol undergo polyesterification to form PET.
a) True
b) False
Answer: a
Clarification: Terephthalic acid and ethylene glycol undergo polyesterification to form PET. It is the most common thermoplastic polymer resin of the polyester family and is used in fibers for clothing, containers, etc.

Engineering Chemistry Multiple Choice Questions on “Calorific Value – 1”.

1. On which property of fuel it’s calorific value is based?
a) Specific heat
b) Efficiency
c) Cost
d) Ignition temperature
Answer: b
Clarification: The calorific value is the total amount of heat liberated by complete combustion a unit amount of fuel, which is the total efficiency of the fuel.

2. What is the unit of calorific value in fps(foot pound sec)?
a) Gram calorie (g cal)
b) Pound calorie
c) British thermal unit/ft3
d) Calorie/gram2
Answer: b
Clarification: B.T.U. is the amount of heat required to rise the temperature of 1 lb of water through 1 0F. Centigrade heat unit (CHU) can also be used in fps system.

3. At how much temperature does the products of combustion should be cooled down to get Gross Calorific Value?
a) 288 K
b) 315 K
c) 390 K
d) 350 K
Answer: a
Clarification: At 288 K the products are cooled down, so as to get exact gross calorific value. It can be cooled down till room temperature.

4. What happens to the hydrogen present in fuel for calculating gross calorific value?
a) It combines with carbon to form methane
b) It combines with chlorine to form hydrochloric acid
c) It combines with oxygen to form hydrogen per oxide
d) It gets converted into steam
Answer: d
Clarification: After combustion of hydrogen, it gets converted into water vapour which then settles down as steam. After this process the products of combustion are cooled down.

5. How does the latent heat of condensation is included in gross calorific value?
a) By the steam produced by the combustion of hydrogen
b) By the combustion of products other than carbon and hydrogen
c) By the combustion of carbon
d) By the total heat produced in the system
Answer: a
Clarification: The steam generated after combustion gets condensed into water and latent heat is evolved. The latent heat so liberated is included in gross calorific value.

6. What’s the basic formulae for calculating gross calorific value?
a) [8080 %C + 3450(%H – %O∕8) + 2240 %S]∕100 cal/gm
b) [8080 %C + 34500(%H – %O∕24) + 2240 %S]∕100 cal/gm
c) [8080 %C + 34500(%H – %O∕16) + 2240 %S]∕100 cal/gm
d) [8080 %C + 34500(%H∕1 – %O∕8) + 2240 %S]∕100 cal/gm
Answer: d
Clarification: This formulae is also called as Dulong’s formula. With the help of %C,%H,%O and %S present in fuel gross calorific value can be calculated.

7. Net Calorific Value is greater than Gross Calorific Value.
a) True
b) False
Answer: b
Clarification: NCV = [GCV – 0.09%H×587] cal/gm, since both GCV and % H are positive the value of NCV will be less than GCV.

8. Which of the following properties a good fuel should have?
a) Low Calorific value
b) Moderate Calorific value
c) High Calorific value
d) High ignition temperature
Answer: c
Clarification: Calorific value is the total amount of heat liberated by complete combustion of fuel, therefore the more the calorific value will be, the good the fuel will be.

9. Which of the fuel has the highest calorific value?
a) Butane
b) Wood
c) Kerosene
d) Natural gas
Answer: a
Clarification: The calorific value of butane is 118 MJ/kg, this is due to the saturation of carbon bonding in butane, where as the calorific value of wood is lowest which is 16 MJ/kg.