A sample of natural gas containing 80% methane (CH4) and rest nitrogen (N2) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is_________________?

Related Mcqs:

1. The calorific value of a gas of composition CO2 = 20%, H2 = 50%, CH4 = 30%, is y. If the composition of gas is changed to H2 = 50%, CH4 = 30%, CO2 = 10%, N2 = 10%, then the calorific value will be___________________?

   A. y
   B. 0.95 y
   C. 1.05 y
   D. 1.8 y

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. Explosion limit of blast furnace gas is 37 to 71% gas in gas-air mixture. It means that the blast furnace gas will explode when burnt in a confined space, if its concentration in the gas-air mixture is _______________ percent?

   A. 71%
   C. In between 37 & 71%
   D. None of these

4. A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the_________________?

   A. Presence of large quantity of hydrogen in the fuel
   B. Low calorific value of the fuel
   C. High sulphur content in the fuel
   D. Lack of thorough mixing of fuel with air

5. Calorific value of gobar gas (containing CH4 = 60% , H2 = 10% ; CO2 = 30%) may be about ______________ Kcal/Nm3?

   A. 1,800
   B. 3,200
   C. 5,400
   D. 10,200

6. If CO2 is not fully absorbed by the KOH solution meant for its absorption in the orsat apparatus, it will appear as___________________?

   A. O2
   B. CO
   C. N2
   D. SO2

7. Nitrogen present in the flue gas is determined in the Orsat apparatus by absorbing it in_____________________?

   A. KOH
   B. Ammoniacal cuprous chloride
   C. Pyrogallol solution
   D. None of these

8. As the C/H ratio of the fuel increases, the amount of CO2 formed on combustion _______________ for the same percentage of excess air?

   A. Decreases
   B. Increases
   C. Remain same
   D. May increase or decrease depending on the type of fuel

9. Which of the following combustibles is absent in blast furnace gas ?

   A. H2
   B. CH4
   C. CO
   D. None of these

10. A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that___________________?

    A. 21% excess air has been used for combustion
    B. 21% excess oxygen has been used for combustion
    C. Complete combustion of fuel has taken place
    D. No excess air has been used for combustion