Give me some responses to the questions below and I'll give you some extra credit.

SID#:

Laboratory Section: 1 2 3 4 5 6

1. The enthalpy of formation, H^o_f , for an unknown compound, AB, in the solid phase and the gaseous phase were determined by experiment. The person doing the experiment forgot to associate the value of the H^o_f to the specific phase. Can you help? The two values were; H^o_f = -23 kJ and -35 kJ. Explain your reasoning.

2. Given a balanced chemical equation explain how you would determine the H^o_rxn?

3. Briefly explain what the term entropy means to you.

4. Identify the phase of the substance in each of the containers labeled A, B and C. Indicate the phase that is most ordered, and most disordered.

5. Indicate for each change if the products are more dissordered or less disorderd (more ordered) compared to the reactants.

a. H₂O(l) ----> H₂O(s)

b. CO₂(s) ----> CO₂(g)

c. 2Na(s) + 2H₂O(l) ----> 2NaOH(aq) + H₂(g)

d. 2H₂(g) + O₂(g) ----> 2H₂O(g)

6. When the products are more dissordered compared to the reactants we say S for the reaction is positive, and if the products are more ordered compared to the reactants we say the S for the reaction is negative. For the following reactions predict the sign of S.

a. 2H₂(g) + O₂(g) ----> 2H₂O(g)

b. Ba(OH)₂^.8H₂O(s) + 2NH₄SCN(s) ----> Ba(SCN)₂(aq) + 10H₂O(l) + 2NH₃(aq)

c. 2NO(g) + 2CO(g) ----> N₂(g) + 2CO₂(g)

d. C₃H₈(g) + 5O₂(g) ----> 3CO₂(g) + 4H₂O(l)

7. In each of the following pairs which is more dissordered.

a) H₂O(l) or H₂O(g)

b) H₂O(l) at 25 degrees Celsius or H₂O(l) at 90 degrees Celsius

8. Is there anything about the questions that you feel you do not understand? List your concerns/questions.