1. A student collected the following data for a fixed volume of gas:
|
Temperature (°C)
|
Pressure (mm of Hg)
|
|
10
|
726
|
|
20
|
750
|
|
40
|
800
|
|
70
|
880
|
|
100
|
960
|
|
150
|
???
|
Fill in the missing data point. Show all calculations leading to an answer.
2. You are given a clear solution of KNO3. Using 3 - 4 sentences (in your own words) explain how you would determine if the solution is unsaturated, saturated or supersaturated.
3. Explain why gasoline will not dissolve in water.
4. Explain in 3 - 4 sentences (in your own words) how perspiration helps keep you cool on a hot day.
5. You have two sealed jars of water at the same temperature. In the first jar there is a large amount of water. In the second jar there is a small amount of water. Using 3 -4 sentences explain how the vapor pressure of water in the first jar compares with the vapor pressure of water in the second jar.
6. Using 3 - 4 sentences explain (in your own words) why water expands when it freezes?
7. Using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. Use 3 - 4 sentences in your explanation.
8. When a 2.5 mol of sugar (C12H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. If 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? Show all calculations leading to your answer OR use 3 - 4 sentences to explain your answer.
9. If 5.40 kcal of heat is added to 1.00 kg of ice at 0°C, how much liquid water at 0°C is produced? Show all calculations leading to an answer.
10. The freezing of water at 0°C can be represented as follows:
H2O (l) ↔ H2O(s)
The density of liquid water is 1.00 g/cm3. The density of ice is 0.92 g/cm3. In 3 - 4 sentences explain why applying pressure causes ice to melt.
11. The Kw of water varies with temperature. Calculate the pH of water at 46°C with a Kw = 1.219 x 10-14. Show all calculations leading to an answer.
12. Calculate the hydroxide ion concentration of a solution with pH = 8.25. Show all calculations leading to an answer.
13. What salt results from the neutralization of acetic acid with potassium hydroxide?
14. What is the oxidation number of phosphorus in P2O3?
15. Which element is oxidized in the following reaction:
CuO(s) + H2 (g)à Cu(s) + H2O (l)
16. Why must the number of electrons lost equal the number of electrons gained in every redox reaction? Use 3 - 4 sentences in your own words to address this question.
17. The following unbalanced equation describes the reaction that can occur when dinitrogen tetroxide, N2O4, is combined with hydrazine, N2H4.
N2O4 (l) + N2H4 (l)àN2 (g) + H2O (g)
Balance the equation and describe in words the electron transfer(s) that takes place.
18. What type of radiation is emitted when K-38 decays into Ca-38? Show the nuclear equation that leads you to this answer.
19. A radioactive nucleus decays to yield a bismuth-211 nucleus and an alpha particle. What was the identity of the original nucleus? Show the nuclear equation that leads you to this answer.
20. Tritium (H-3) has a half-life of 12.3 years. How old is a bottle of olive oil if the tritium content is 25% that of a new sample of olive oil? Show all calculations leading to a solution.