UNIT 8

Unit 3: 

Chemistry chapter 16, 17 study guide

Chapter 16:

Understand the following terms:

-Temperature

-heat

-Specific heat

-Enthalpy change

-Thermochemical equation

2. Be able to calculate specific heat of a reaction:

-You need 70.2 J to raise the temperature of 34.0g of ammonia (NH3) from 23.0 to

24.0C. Calculate the specific heat of ammonia.

3. Understand how to use enthalpy of formation and enthalpy of combustion data to calculate

the enthalpy of reaction for a specific chemical reaction:

-Calculate the enthalpy of formation of ethane (C 2 H 6 ) using enthalpy of combustion and

formation data from Appendix A-5 and A-14.

4. Understand what is meant by entropy and free energy. Be able to relate free energy change

to the spontaneity of the reaction.

5. Be able to calculate entropy or free energy change:

-A reaction has ΔH= -356kJ and ΔS= -36J/K. Calcualte ΔG at 25C and confirm if the

reaction is spontaneous.

6. Determine which processes increase or decrease the entropy of the system.

7. Be able to write enthalpy of formation, and enthalpy of combustion reactions.

Ex. Write formation of CaCO 3 , Combustion of C 6 H 12 O 6