Chemistry I: Matter & Energy Review
Define the following terms:
1. Energy
2. Kinetic energy
3. potential energy
4. Exothermic
5. Endothermic
6. Conservation
7. Temperature
8. Hypothesis
9. Variable
10. Theory
11. Law
12. Conclusion
13. Conservation of mass
14. Precision
15. Accuracy
16. Chemistry
17. Chemical property
18. Physical property
19. Chemical change
20. Physical change
21. Solid
22. Liquid
23. Gas
24. Homogeneous
25. Heterogeneous
26. Quantitative
27. Qualitative
Short Answer:
Describe the energy change involved when an egg cooks.
Explain the difference in an endothermic process and an exothermic process.
Explain how energy is conserved when a piece of paper burns.
Use pouring hot chocolate into a cold cup to explain the difference in heat and temperature.
Explain how to change from Kelvin to degrees Celsius.
Why should a scientist record all observations, even those that appear insignificant?
What are the first steps scientists take to analyze the cause of a disease?
Explain what is meant by a scientific method.
What is the purpose of a control in an experiment?
Explain why pictures of atoms and molecules are models.
Differentiate between a theory and a law.
The mass of a 3.45-g piece of aluminum was measured several times. The measured masses were 2.67g,2.59g,2.60g,and2.64g. Use these results to explain the difference between accuracy and precision.
The specific heat of iron is 0.449 J/(g K), and that of aluminum is 0.897 J/(g K). Explain how you know which metal will absorb and release more energy under the same temperature change. Assume samples of equal mass.
Explain why the number 62.605 x 106 is not in correct scientific notation. What is the correct scientific notation for this number?
A 10.0 g sample of cadmium absorbed 43 J of energy as it was heated. The initial temperature was 285 K. What was the final temperature of the metal if the specific heat of cadmium is0.232J/(g K)?
The specific heat of tin is 0.228 J/(g K). A sample of tin absorbs 92 J as it is heated from271Kto295K. What is the mass of the sample?
The specific heat of carbon is 0.709 J/(g K). How much energy is absorbed if a 7.34 g sample is heated until its temperature increases by 12 K?
If a 12.6 g sample of a material is heated from 181 K to 199 K, 46 J of energy is absorbed. What is the specific heat of the material?
When water boils, steam forms. When vinegar and baking soda combine, carbon dioxide gas is released. Which change is physical, and which is chemical? How do you know?
State which one of the following observations is quantitative and explain why it is.
a. The liquid turns blue litmus paper red.
b. The liquid boils at 100°C.
c. The liquid tastes bitter.
d. The liquid is cloudy.
Explain the difference between a pure substance and a homogeneous mixture. Use an example in your explanation
Name three different ways that mixtures can be separated.