Thermo1

In this PLE we are going to continue our investigate acids and bases. (NOTE: If you can not answer a question below enter CNA.)

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

SID#:

Laboratory Section:

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

2. Which phase for a pure substance contains more energy; gas, liquid or solid? Explain

3. 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)

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

5. 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)

6. 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

7. Explain how heat flows between the system and surrounding for an exothermic reaction? For an endothermic reaction?

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