1. Objective: To calculate density.

4. - Volume of a cube or block = length x width x height - Volume of irregular shaped object = use water displacement

6. Density density = mass/volume OR d = m/v d = Example: An object has a mass of 22 g and a volume of 11 cm 3. What is the density of this object?

9. Example #1 1.An object has a mass of 18.9 g and a volume of 7.0 mL. What is the density? 2.What is it? (refer to table of densities on page 17)? 3.Will it float?

10. Example #1: Answer 1.An object has a mass of 18.9 g and a volume of 7.0 mL. What is the density? d = m/v = 18.9 g / 7.0 mL = 2.7 g/mL 2. What is it? (refer to table of densities on page 17)? Aluminum 3. Will it float? 2.7 g/mL > density of water (1.0 g/mL) SINK

11. Example #2 1.A liquid has a mass of 4.743 g and a volume of 6.0 mL. What is the density? 2.What is it (refer to the table of densities on page 17)? 3.Will it float?

12. Example #2: Answer 1.A liquid has a mass of 4.743 g and a volume of 6.0 mL. What is the density? d = m/v = 4.743 g/6.0 mL = 0.79 g/mL 2. What is it (refer to the table of densities on page 17)? ethanol 3. Will it float? 0.79 g/mL < density of water (1.0 g/mL)  float

13. Example #3 What is the density of a cube with a length of 5.0 cm and a mass of 26 g?

14. Example #3: Answer What is the density of a cube with a length of 5.0 cm and a mass of 26 g? Volume = length x width x height Volume = 5.0 cm x 5.0 cm x 5.0 cm = 125 cm 3 Density = m/v = 26 g/125 cm 3 = 0.21 g/cm 3

15. Example #4 An irregularly shaped stone was lowered into a graduated cylinder holding a volume equal to 2.0 mL. The height of the water rose to 7.0 mL. If the mass of the stone was 25 g, what was the density?

16. Example #4: Answer An irregularly shaped stone was lowered into a graduated cylinder holding a volume equal to 2.0 mL. The height of the water rose to 7.0 mL. If the mass of the stone was 25 g, what was the density? Volume = 7.0 mL – 2.0 mL = 5.0 mL Density = m/v = 25 g / 5.0 mL = 5.0 g/mL

17. Density Equation Density = Mass/Volumed = m/v Mass = Density x Volumem = d x v Volume = Mass/Densityv = m/d

18. Example #5 If the density of an object is 8.7 g/mL and the volume is 15 mL, what is the mass of the object?

19. Example #5: Answer If the density of an object is 8.7 g/mL and the volume is 15 mL, what is the mass of the object? Mass = d x v Mass = 8.7 g/mL x 15 mL Mass = 130.5 g  130 g

20. Example #6 If the density of an object is 3.6 g/mL and the mass is 60.0 g, what is the volume of the object?

21. Example #6: Answer If the density of an object is 3.6 g/mL and the mass is 60.0 g, what is the volume of the object? Volume = m/d Volume = (60.0 g) / (3.6 g/mL) Volume = 16.67 mL  17 mL

22. Example #7 If the density of an object is 5.5 g/mL and the mass is 1.2 kg, what is the volume of the object?

23. Example #7: Answer If the density of an object is 5.5 g/mL and the mass is 1.2 kg, what is the volume of the object? Volume = m/d Volume = 1200 g/(5.5 g/mL) Volume = 218 mL  220 mL

24. Example #8 5.0 mL of the ethanol has a mass of 3.9 g, and 5.0 mL of benzene has a mass of 4.4 g. Which liquid is denser?

25. Example #8: Answer 5.0 mL of the ethanol has a mass of 3.9 g, and 5.0 mL of benzene has a mass of 4.4 g. Which liquid is denser? EthanolBenzeneDensity = Mass/Volume Density = 3.9 g/5.0 mLDensity = 4.4 g/5.0 mL Density = 0.78 g/mLDensity = 0.88 g/mL Benzene is more dense.