THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.
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Transcript of THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.
![Page 1: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/1.jpg)
THERMOCHEMISTRY REVIEW
You need a marker board, marker, eraser, & your Chemistry book.
![Page 2: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/2.jpg)
What is the difference between kinetic and potential energy?
• Potential energy is stored energy (as in chemical bonds)
• Kinetic energy is the energy of motion (as in the motion of molecules)
![Page 3: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/3.jpg)
What is the difference between temperature and heat.
• Heat is the total energy stored
• Temperature is the average kinetic energy of the molecules
![Page 4: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/4.jpg)
Write the mathematical relationship between joules and calories.
• 1 calorie = 4.18 joules
Write the mathematical relationship between calories and kilocalories.
1000 calories = 1 kilocalorie
![Page 5: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/5.jpg)
A banana has 110. nutritional calories. How many joules of
energy are in the banana?
• 4.60 x 105 joules
![Page 6: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/6.jpg)
Endothermic reactions have ___________ H values
and exothermic reactions have ___________ H values
• Positive
• Negative
![Page 7: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/7.jpg)
In an endothermic reaction the (system/surroundings) loses
energy and the (system/surroundings) gains
energy
• Surroundings
• System
![Page 8: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/8.jpg)
Endothermic or Exothermic
• Ice Freezing• Dry Ice Subliming• Burning Marshmallow• Sweat Evaporating
• Exothermic• Endothermic• Exothermic• Endothermic
![Page 9: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/9.jpg)
What is meant by specific heat?
• The amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius
![Page 10: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/10.jpg)
Describe a calorimeter. What is it used for?
• A calorimeter is an insulated device, A calorimeter is an insulated device, such as a Styrofoam cup, used to such as a Styrofoam cup, used to measure the amount of heat absorbed measure the amount of heat absorbed or released during a chemical reaction.or released during a chemical reaction.
![Page 11: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/11.jpg)
Use the table of specific heat values on page 492 of your text to
answer the following question.
The temperature of a sample of iron with a mass of 15.0 g changed from
25.5°C to 85.6°C. How many kilojoules of energy did this process take?
• q = (15.0)(0.449)(60.1) = 405 J = 0.405 kJ
![Page 12: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/12.jpg)
Draw a heating curve for ammonia as it is warmed from -120°C to 300°C. The freezing point of
ammonia is -108°C and its boiling point is 270°C.
![Page 13: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/13.jpg)
If 0.345 kJ of heat is released by 125 g water as it cools down from
85.2°C, what is it’s new temperature?
• 85.86ºC
![Page 14: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/14.jpg)
If the heat of fusion for ammonia is 5.66 kJ/mol, how many kJ would be
required to melt 22.6 g of ammonia?
• 7.51 kJ
![Page 15: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/15.jpg)
Using the following thermochemical equation: 2CO(g) + O2(g) 2CO2(g) ΔH = -566.0 kJ,
answer the following questions.
a. If 2.45 g of CO(g) reacts with sufficient oxygen gas, how many kJ of heat are released?
b. How many grams of carbon dioxide were produced when 234 kJ of heat were made?
• a. - 24.8 kJ
• b. 36.4 g CO2
![Page 16: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/16.jpg)
Given the following data, determine the ΔH for the reaction:
2 Cu(s) + O2(g) 2 CuO(s)4CuO (s) 2Cu2O (s) + O2 (g)
ΔH = 288kJCu2O (s) Cu (s) + CuO (s)
ΔH = 11kJ
• -310 kJ (1st reaction flipped, 2nd flipped and doubled)
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What is meant by the term “enthalpy?”
• Enthalpy (H) is the heat content of a system at a constant pressure
![Page 18: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/18.jpg)
Explain how the Heat of Fusion and the Heat of Vaporization are
the same and different.
![Page 19: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/19.jpg)
Which has more entropy, a sugar cube or a sugar solution?
• Sugar Solution
If a sugar cube dissolves in water, is the “S” for the reaction positive or negative?
Positive
![Page 20: THERMOCHEMISTRY REVIEW You need a marker board, marker, eraser, & your Chemistry book.](https://reader035.fdocuments.in/reader035/viewer/2022062408/56649e665503460f94b60ca2/html5/thumbnails/20.jpg)
Calculate the ΔG for this reaction at 298 K (room temperature ) and 1000K (very hot). Determine if each reaction is spontaneous.
O2 + O O3
ΔH = -106.5kJ ΔS = -127.4 J/K
Answer: at 298K ΔG=-68.5kJ so the reaction is spontaneousat 1000K ΔG=20.9 kJ so the reaction is not spontaneous