حرارتی کیمیا

Written by Dr. Ayesha Nadeem (Chemistry)

گیارہویں جماعت · کیمیا · 8 سوالات

نام: ____________________   تاریخ: ____________

1. In an exothermic reaction, the enthalpy change is:

   • A Positive
   • B Negative
   • C Zero
   • D Infinite

2. Hess's law states that the enthalpy change of a reaction depends on:

   • A The speed
   • B The path taken
   • C Only the initial and final states
   • D The catalyst

3. The standard enthalpy of formation of an element in its standard state is:

   • A 0
   • B -1 kJ/mol
   • C 1 kJ/mol
   • D 100 kJ/mol

4. Bond breaking is:

   • A Exothermic
   • B Endothermic
   • C Neither
   • D Always a catalyst process

5. Heat of combustion is the heat released when one mole of a substance:

   • A Melts
   • B Boils
   • C Dissolves
   • D Burns completely in oxygen

6. The enthalpy change for the reaction C + O2 giving CO2 is -394 kJ/mol. This reaction is:

   • A Not possible
   • B Exothermic
   • C Endothermic
   • D Thermoneutral

7. The heat needed to raise 1 g of water by 1 degree C is about:

   • A 0.42 J
   • B 420 J
   • C 42 J
   • D 4.2 J

8. The standard state of a substance refers to its state at:

   • A Any pressure
   • B 100 degrees C only
   • C 1 atm pressure and 298 K
   • D 0 atm and 0 K