CHM 2045C  Module 7 Thermochemistry  Name: __________________

 

Module Seven: Part B Discussion Questions    10 points

For the exam, your instructor will select four of the following questions for you to write the answers:

 

1. What is the standard state of an element or compound substance?

 

 

 

 

 

2. Why does water have a high specific heat capacity?  What does this mean?

 

 

 

 

 

3. Write four different mathematical expressions for the 1st Law of Thermodynamics. How are they related?

 

 

 

 

 

4. Where does the energy come from in an endothermic process? And where does it go?

 

 

 

 

5. Define standard molar enthalpy of formation Hºf  . Why is the standard enthalpy of formation of a pure element in its most stable form defined as zero?

 

 

 

 

6. Define a spontaneous reaction. How can you tell whether a reaction is spontaneous?

 

 

 

7. A system can exchange energy with its surroundings either by transferring heat or by doing work. This is expressed by the following equation: Δ E = q  +  w

Fill in the chart with correct signage:

Change                                                         Sign Conversion    Effect of Esystem

Work done on the system by surroundings           

Work done by the system on surroundings           

Heat transferred to system from surroundings      

Heat transferred from system to surroundings