Heat of formation of an element in its standard state is___________________?

Related Mcqs:

1. The amount of heat required to decompose a compound into its elements is _____________ the heat of formation of that compound from its elements?

   A. Less than
   B. More than
   C. Same as
   D. Not related to

2. Heat requirement for decomposition of a compound into its elements is _____________ that is evolved during the formation of that compound from its elements?

   A. The same
   B. Less than
   C. Greater than
   D. Different than

3. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?

   A. 100,000 kW
   B. 160,000 kW
   C. 200,000 kW
   D. 320,000 kW

4. The standard state of a gas (at a given temperature) is the state in which fugacity is equal to__________________?

   A. Unity
   B. Activity
   C. Both A. & B
   D. Neither A. nor B

5. Those solutions in which there is no volume change upon mixing the components in the liquid state and which, when diluted do not undergo any heat change (i.e. heat of dilution is zero), are called ____________ solutions?

   A. Ideal
   B. Real
   C. Isotonic
   D. None of these

6. What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ?

   A. AB3
   B. A2B3
   C. A2B
   D. AB2

7. Compound having large heat of formation is_____________________?

   A. More stable
   B. Less stable
   C. Not at all stable (like nascent O2)
   D. Either more or less stable; depends on the compound

8. The combustion equations of carbon and carbon monoxide are as follows: C + O2 = CO2, ΔH = – 394 kJ/kg .mole CO + ½ O2 = CO2, ΔH = – 284.5 kJ/kg. mole. The heat of formation of CO is _____________ kJ/kg. mole?

   A. -109.5
   B. +109.5
   C. +180
   D. +100

9. Absorption/evolution of heat during conversion of a substance from one allotropic form to another is termed as the heat of _____________________?

   A. Sublimation
   B. Fusion
   C. Transition
   D. Vaporisation

10. The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 – T2)/T1. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2 is given by__________________?

    A. T1/(T1-T2)
    B. T2/(T1-T2)
    C. T1/T2
    D. T2/R1