Thermodynamics (Fuels and Combustions)

1. The smallest particle which can take part in a chemical change is called
(a) atom
(b) molecule
(c) electron
(d) compound.

2. A chemical fuel is a substance which releases ...... on combustion.
(a) chemical energy
(b) heat energy
(c) sound energy
(d) magnetic energy.

3. The most important solid fuel is
(a) wood
(b) charcoal
(c) coal
(d) all of the above.

4. For each mole of oxygen, number of moles of nitrogen required for complete combustion of carbon are
(a) 20/21
(b) 2/21
(c) 77/21
(d) 79/21.

5. Modern practice is to use ...... excess air.
(a) 5 to 10 per cent
(b) 15 to 20 per cent
(c) 20 to 25 per cent
(d) 25 to 50 per cent

6. Stoichiometric air-fuel ratio by mass for combustion of petrol is
(a) 5
(b) 10
(c) 12
(d) 15.05.

7. An analysis which includes the steam in the exhaust is called
(a) dry analysis
(b) wet analysis
(c) dry and wet analysis
(d) none of the above.

8. The Orsat apparatus gives
(a) volumetric analysis of the dry products of combustion
(b) gravimetric analysis of the dry products of combustion
(c) gravimetric analysis of products of combustion including H2O
(d) volumetric analysis of products of combustion including H2O.

9. In the Orsat apparatus KOH solution is used to absorb
(a) carbon monoxide
(b) carbon dioxide
(c) oxygen
(d) none of the above.

10. Enthalpy of formation is defined as enthalpy of compounds at
(a) 25°C and 10 atmospheres
(b) 25°C and 1 atmosphere
(c) 0°C and 1 atmosphere
(d) 100°C and 1 atmosphere.

11. Bomb calorimeter is used to find the calorific value of ...... fuels.
(a) solid
(b) gaseous
(c) solid and gaseous
(d) none of the above.

12. When the fuel is burned and the water appears in the vapour phase, the heating value of fuel is called
(a) enthalpy of formation
(b) lower heating value
(c) higher heating value
(d) none of the above.

13. Heat released in a reaction at constant pressure is called
(a) entropy change
(b) enthalpy of reaction
(c) internal energy of reaction
(d) none of the above
(e) all of the above.

14. When the fuel is burned and water is released in the liquid phase, the heating value of fuel is called
(a) higher heating value
(b) lower heating value
(c) enthalpy of formation
(d) none of the above.

15. Choose the correct statement :
(a) Number of atoms of each constituent are not conserved in a chemical reaction.
(b) The mass of all the substances on one side of the equation may not be equal to the mass of all the substances on the other side.
(c) The number of atoms of each constituent are conserved in a chemical reaction.
(d) The number of moles of the reactants in a chemical equation are equal to the number of moles of the products.

Answers
1. (a)    2. (b)    3. (c)    4. (d)    5. (d)    6. (d)    7. (b)    8. (a)    9. (b)    10. (b)
11. (a) 12. (b) 13. (b) 14. (a)    15. (c).

Comments

Popular posts from this blog

Electrical Machines (Three Phase Transformers)

Thermodynamics (Compressible Flow)

Electrical Machines (Special Machines)