For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = – 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be__________________?

Related Mcqs:

1. The fugacity of liquid water at 298 K is approximately 3171 Pa. Considering the ideal heat of vaporisation as 43723 J/gm.mole, its fugacity at 300 K would be________________?

   A. 3171Pa
   B. 3567Pa
   C. 1.01 × 105Pa
   D. 5000Pa

2. The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is___________________?

   A. Full annealing
   B. Bright annealing
   C. Patenting
   D. None of these

3. Consider an ideal solution of components A and B. The entropy of mixing per mole of an alloy containing 50% B is_______________?

   A. R ln 2
   B. -R ln 2
   C. 3 R ln 2
   D. -3R ln 2

4. In a furnace with heating element temperature at 1700°C, the dominant mechanism of heat transfer will be__________________?

   A. Conduction
   B. Radiation
   C. Natural convection
   D. Forced convection

5. Which of the following are made out of the carbon steel having carbon content of 0.9 to 1%?

   A. Small punches, broaches reamers and springs
   B. Cutlery, screws, rivets and files
   C. Mandrels, twist drills, small lathe tools and razors
   D. Forgings like can shaft, structural steel plate, threading dies and drawing dies

6. The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : Cp of copper is 23 J K-1mole-1) ?

   A. 2300 J
   B. 4600 J
   C. 230 J
   D. 2.3 × 106 J

7. Which of the following is the most wear resistant grade of carbide used for the cutting tools ?

   A. Aluminium carbide
   B. Tungsten carbide
   C. Nickel carbide
   D. Iron carbide

8. Carbide tipped cutting tools are manufactured by powder metallurgy techniques and have a composition of_____________________?

   A. 90% tungsten carbide and 10% cobalt
   B. 70% aluminium oxide & 30% silica
   C. 30% nickel, 15% chromium & 55% tungsten
   D. 65% tungsten & 35% zirconium

9. Cemented carbide tools are not suitable for cutting___________________?

   A. Aluminium
   B. Brass
   C. Cast iron
   D. Steel

10. In a totally irreversible isothermal expansion process for an ideal gas, ΔE = 0, ΔH = 0. Then ΔQ and ΔS will be_______________?

    A. ΔQ = 0, ΔS=0
    B. ΔQ = 0, ΔS = +ve
    C. ΔQ = 0, ΔS = -ve
    D. ΔQ = +ve, ΔS= +ve