Process Calculations – Multiple Choice Questions (MCQs)

1. 25. What is relative humidity?

   • A. Ratio of actual partial pressure of water vapor to saturation partial pressure at the same temperature
   • B. Mass of water vapor per unit mass of dry air
   • C. Temperature at which air becomes saturated with water vapor
   • D. Amount of water in a liquid stream

2. 26. What is dew point?

   • A. The temperature at which air becomes saturated with water vapor at constant pressure
   • B. The temperature at which water boils
   • C. The temperature at which water freezes
   • D. The dry-bulb temperature

3. 27. What is wet-bulb temperature?

   • A. The temperature measured by a thermometer with a wet wick exposed to air
   • B. The dry-bulb temperature
   • C. The dew point temperature
   • D. The boiling point

4. 28. What is a psychrometric chart used for?

   • A. To analyze the properties of moist air
   • B. To determine reaction kinetics
   • C. To design distillation columns
   • D. To calculate fluid flow rates

5. 29. What is excess air in combustion calculations?

   • A. Air supplied in excess of the stoichiometric amount required for complete combustion
   • B. Air supplied less than the stoichiometric amount
   • C. Air that is not used in combustion
   • D. Air that is recycled

6. 30. What is limiting reactant?

   • A. The reactant that is completely consumed in a chemical reaction
   • B. The reactant that is in excess
   • C. The product of a reaction
   • D. A catalyst in a reaction

7. 31. What is fractional conversion?

   • A. The fraction of the limiting reactant that has been converted into products
   • B. The total amount of reactant consumed
   • C. The amount of product formed
   • D. The efficiency of the reactor

8. 32. What is yield in a chemical reaction?

   • A. The amount of product formed relative to the theoretical maximum
   • B. The rate of reaction
   • C. The energy released in a reaction
   • D. The purity of the product

9. 33. What is selectivity in a chemical reaction?

   • A. The ratio of moles of desired product formed to moles of undesired product formed
   • B. The rate of reaction
   • C. The purity of the product
   • D. The amount of reactant consumed

10. 34. What is enthalpy?

    • A. A measure of the total energy of a thermodynamic system
    • B. A measure of disorder
    • C. A measure of temperature
    • D. A measure of pressure

11. 35. What is heat capacity (Cp)?

    • A. The amount of heat required to raise the temperature of a substance by one degree Celsius (or Kelvin) at constant pressure
    • B. The amount of heat required to melt a substance
    • C. The amount of heat released during a reaction
    • D. The amount of heat lost to surroundings

12. 36. What is latent heat?

    • A. Heat associated with a change in temperature
    • B. Heat absorbed or released during a phase change at constant temperature
    • C. Heat transferred through convection
    • D. Heat transferred through radiation