2. Chapter 3 Characteristic Properties

3. Properties of Substances and Properties of Objects Objects Sharp Small Mass Volume Beautiful Carved Substances Conducts Electricity Color Boiling Point Freezing Point Density Volatility

4. Freezing and Melting A Characteristic Property Plateau

5. Phase Diagram Liquid Solid

6. Graphing Rules Axes must cover the entire range of your data points Spread the graph out over your paper. Make sure you choose a division that corresponds to a unit that makes plotting and reading easy. Use titles with units on each axes. Draw smooth curves NOT connect the dots.

7. Boiling Point Plateau

8. Boiling Point and Air Pressure Use a barometer to measure pressure. Remember the demonstration where we got the water to boil at about 60oC We cooled it causing a low pressure to be inside the flask. Low pressure  Lower boiling point High pressure  Higher boiling point

9. Pressure Cookers are used to increase the boiling point of water.

10. Boiling Point Decreases with Elevation Degrees C Elevation (m)

11. Mass vs. Volume Conclusions Substances can have the same volume and be different. Substances can have the same mass and be different. Substances with the same Mass/Volume ratio can be the same substance.

12. Density

15. Using Measured Numbers The answer should only display the least number of significant digits. Example: 14.35/6.5 = 2.207692308 Only report answer as 2.2 (2 significant digits)

16. Try this one…. 1.56 x 2.614 x 5.4 = 22.020336

17. Answer 22.020336

18. Density of Solids Find the mass (in grams) Find the volume (sometimes using a mathematical formula or sometimes using water displacement) (in cubic cm) Remember the formula for rectangular solid is l x w x h

19. Density of Liquids Find the mass of the liquid. (Mass the container that the liquid is in from the mass of the container and liquid) Find the volume of the liquid using the graduated cylinder.

20. Density of a Gas Find the difference of the masses of the test tube, alka-seltzer and water before and then after the reaction. Subtract to find the mass. Determine the volume of the gas by subtracting the volume of the water left from what you started with. Use the density formula to find the density.

21. Density of Gases Varies with the temperature and pressure. So you need to give the temp and pressure when giving the density of a gas. Same mass, different volume, therefore different density

22. Density Comparison of Solids, Liquids and Gases For the most part: Solids are 2 g/cm 3 or greater Liquids are close to 1 g/cm 3 Gases are around.001 -.002 g/cm 3

23. Using Characteristic Properties to Identify Substances Properties studied were: Melting Point, Boiling Point and Density. We cannot depend on two properties alone to distinguish between substances. If you can’t determine all the three above you need to look for other characteristic properties such as conductivity.

24. Assignments this chapter 1 st quarter Substance/Object Worksheet Lab on using graphing calculator Lab 3.2 Freezing Point + Questions Graph of Freezing Point (Computer and Paper) Lab 3.4 Boiling Point and Graph Graphing Practice and questions p. 45 Questions p. 49: 6 & 7 Lab 3.6 Mass and Volume Internet Density Lab Questions p. 51: 8-11 Lab 3.9 Density of Solids

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