Stoichiometric combustion of 12 kg of carbon requires _____________ of oxygen?

Related Mcqs:

1. One kg of carbon for theoretically complete combustion requires ______________ kg of air?

   A. 11.5
   B. 0.5
   C. 23
   D. 12

2. Pure carbon is completely burnt in oxygen. The flue gas analysis is 70%CO2, 20%CO and 10%O2. The percent excess oxygen used is __________________?

   A. 20
   B. 12.5
   C. 0
   D. 10

3. A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be_________________?

   A. More
   B. Less
   C. Same
   D. Data insufficient; can’t be predicted

4. Use of excess of combustion air in the combustion of fuels results in__________________?

   A. Heat losses
   B. Long flame
   C. Condensation of water vapour from the fuel gas
   D. None of these

5. Deficiency of combustion air during combustion of a gaseous fuel_____________________?

   A. Lengthens the flame
   B. Causes heat loss of fuel by its partial combustion
   C. Both A. & B.
   D. Shortens the flame

6. Oxygen required for theoretically complete combustion of 1 Nm3 methane is ______________ Nm3?

   A. 2
   B. 4
   C. 6
   D. 1

7. Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around ______________ percent?

   A. 4
   B. 96
   C. 20
   D. 40

8. The difference between total carbon and fixed carbon of coal will be minimum in case of___________________?

   A. Lignite
   B. Bituminous coal
   C. Anthracite
   D. High temperature coke (V.M < 0.5%)

9. The ratio of % total carbon obtained in the ultimate analysis of coke and % fixed carbon obtained in the proximate analysis is always ___________________?

   A. 1
   B. < 1
   C. > 1
   D. Unpredictable

10. A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon _________________?

    A. Is less liable to spontaneous combustion on storage
    B. Is more difficult to ignite and produces a shorter flame
    C. Requires smaller combustion space and less secondary air
    D. None of these