a. True
b. False
B. The flask would probably feel warmer than before the reaction started.
C. The flask would feel the same as before the reaction started.
D. none of the above
Answer: A. The flask would probably feel cooler than before the reaction started.
Explanation: An endothermic reaction is a type of of chemical reaction in which energy is absorbed from the surroundings. The temperature of the surrounding decreases.
An Exothermic reaction is a type of of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.
When an endothermic reaction takes place in the flask, the heat is absorbed by the flask and thus the temperature of the surrounding (here the flask) will decrease which can be felt by touching the outside of the test tube. Thus the flask would appear colder.
CCA Unit 3: Heat Energy and Reactions Unit Test Answers
Please keep in mind these are for CHECKING YOUR ANSWERS, not for using as an answer key to cheat!!
1. A
2. C
3. A
4. A
5. C
6. D
7. C
8. C
9. A
10. A
11. C
12. A
13. C
14. C
15. C
16. B
17. D
18. B
19. Q= = mass * specific heat * delta T 343 = 55.0 * specific heat (86.0-19.0) 343=3685 * specific heat specific heat = 0.0931 cal/g Celsius
20. Temperature is absolute while heat is relative. The direction of heat always travels to the warmer temperature of the object to the cooler one.
21. Ke=[C]^2/[A]^3[B}^2
22. A chemical reaction is spontaneous if an increase in the total entropy of the system and surroundings accompanies it.
Example:
4 Fe + 3 O 2 -> Fe 2 O 3
Enjoy guys ;)
The answer is false.
give the answer in watts to three significant figures