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 Hf . 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