Thermodynamics Test Review 1112x

thoughtgreenpepperMechanics

Oct 27, 2013 (3 years and 9 months ago)

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Thermodynamics Test Review


1. Define endothermic.


2. What is

H for an endothermic reaction?


3. Define exothermic.


4. What is

H for an exothermic reaction?


5. Be able to calculate heat or specific heat using q=mc

T


a. How

much heat is released when 25 mL of water is heated 5
°
C. The specific heat of water is 4.184
J/g
°
C?







b. The temperature change of a 1.5
-
g sample of metal was 2.5
°

when that metal absorbed 675 kJ of
heat. Calculate the specific heat of the metal.








6. Understand entropy. When is

S positive and when is

S negative?



Determine

S for the following phase changes.



a. (l)


(g)



b. (g)


(s)



c. (s)


(aq)



d. (l)


(aq)



e. (l)


(s)







7.
Understand a potential energy diagram
and recognize if it is exothermic or endothermic.
























8. Be

able to read and interpret a phase change diagram. Locate the freezing point, melting point,
boiling point, condensation point. Be able to determine when the substance is a solid, liquid, or a gas.










9. What is the symbol for free energy?


10.

What is

G for a nonspontaneous (needs energy) reaction?


11. What is

G for a spontaneous (releases energy) reaction?


12. Calculate

G using the equation

G=

H
-
T

S and the following data.



H =
-
68.5 kJ/mol



S = 95.2 J/mol K


T = 298 K



13. Be

able to calculate

H using the information below:




H kJ/浯l

Na(s)

0.0

H
2
O(l)

-
286

NaOH(aq)

-
470

H
2
(g)

0.0


Calculate

H for the following reaction:


2Na(s) + 2H
2
O(l)


2NaOH(aq) + H
2
(g)





14. The ΔH of N
2
O
5
(g) is to be determined using the
thermodynamic data shown below.



2H
2
(g) + O
2
(g)

2H
2
O(l)



ΔH =
-
285.8 kJ/mol



2N
2
O
5
(g) + 2H
2
O(l)


4HNO
3
(l)



ΔH =
-
153.2 kJ/mol



N
2
(g) + 3O
2
(g) + H
2
(g)


2HNO
3
(l)


ΔH =
-
174.1 kJ/mol




Using the thermodynamic data above, determine the ΔH of for the

following reaction:




2N
2

+ 5O
2



2N
2
O
5






15.
Be able to solve:

A metal with a
mass of 12.2 grams and an initial temperature of 100.5
°
C is added to 25.0 grams of water
with an initial temperature of 23.5
°
C. After the metal was added, the temperature

of the water rose to
29.0
°
C. Calculate the specific heat of the metal. The specific heat of water is 4.184 J/g
°
C.