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) ?

Related Mcqs:

1. Heating the Hypo-eutectoid steels to 30°C above the upper critical temperature line, soaking at that temperature and then cooling slowly to the room temperature to form a pearlite & ferrite structure is called_______________________?

   A. Tempering
   B. Hardening
   C. Annealing
   D. Normalising

2. Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the ______________ temperature of air?

   A. Wet bulb
   B. Dry bulb
   C. Saturation
   D. Dew point

3. 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

4. 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__________________?

   A. 30,000 J
   B. 60,000 J
   C. 90,000 J
   D. 2,40,000 J

5. The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400°C is__________________?

   A. Magnesite
   B. Chrome
   C. Silica
   D. Fireclay

6. The ratio of thermal & electrical conductivity is same for all the metals at the same temperature; and at around room temperature, this ratio is proportional to(where, T = absolute temperature, °K) ?

   A. T
   B. 1/T
   C. T2
   D. 1/T2

7. The boiling & freezing points on a newly defined temperature scale in degree ‘D’ are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to _____________ °D ?

   A. 140
   B. 180
   C. 240
   D. 280

8. One face of a furnace wall is at 1030°C and the other face is exposed to room temperature (30°C). If the thermal conductivity of furnace wall is 3 W. m-1. k-1 and the wall thickness is 0.3 m, the maximum heat loss (in W/m) is____________________?

   A. 100
   B. 900
   C. 9000
   D. 10000

9. Evaporative cooling process employs a combination of cooling and humidification in which the____________________?

   A. Sensible heat is added
   B. Sensible heat is removed and the latent heat is added
   C. Latent heat is removed
   D. Sensible heat is added and latent heat is removed

10. The minimum temperature to which the water can be cooled in a cooling tower is the ______________ temperature of air?

    A. Ambient
    B. Dry bulb
    C. Dew point
    D. Wet bulb