Sink or float?

1. This file was made to be used in view format. Please click slide show and go through the slides one at a time and answer the questions. The answers start at slide 16

2. Sink or float? • Objects that float in water have a density of _________. • Objects that sink in water have a density of __________. • Objects that “flink” in water have a density of _________.

3. If there are 2 graduated cylinders, one filled with alcohol (D=.8611 g/mL) and the other with water . . . • with same mass, compare the volumes. • with same volume, compare the masses. • If there is no balance available, how do we tell which is alcohol and which is water?

4. For each of the next slides, make a hypothesis of what you think will happen (hypothesis), then click to see what does happen, then explain why it happens.

5. Place can of Coke and Diet Coke in water • Hypothesis: • What actually happened: • Why?

6. Coke held upright in water then opened • Hypothesis: • What actually happened: • Coke stays in can; carbon dioxide leaves the can • Why?

7. Diet Coke placed upright in water and opened • Hypothesis: • What actually happened: • Diet Coke and carbon dioxide both come out of the can • Why?

8. Orange with peel on placed in water • Hypothesis: • What actually happened: • Why?

9. Orange without peel placed in water • Hypothesis: • What actually happened: • Why?

10. Grape in 7-up • Hypothesis: • What actually happened: • Grape sinks then rises to the surface, after a while the grape sinks again • Why? Grape without peel Grape with peel

11. Hot and cold water • Hypothesis: • What actually happened: • The hot water (red) was on top and the cold water (blue) was on the bottom • Why? Picture on next slide

13. Bar of soap in water • Hypothesis: • What actually happened: • All bars of soap sank except the ivory • Why? Picture on next slide

14. Dial Lever 2000 Coast Dove Ivory

15. Complete each statement • 2 objects of same volume, the object with more mass is _______ dense • To make 2 different objects have the same mass, increase the volume of the ______ dense object • 2 objects of same mass, the more dense object has a _______ volume • When keeping volume of a substance the same and increasing mass, density ________ • While keeping mass of a substance the same, if volume is increased then the density is __________ • The relationship between density and volume is ________________ • The relationship between density and mass is ______________

16. Two liquids, A and B, have densities 0.75 g/mL and 1.14 g/mL respectively.When both liquids are poured into a container, one liquid floats on top of the other. Which liquid is on top? • How many kg of mercury would fill a 5.0 L container if the density of mercury is 13.6 g/cm³? • How much space does 1 kg of butter occupy if the density of butter is 0.94 g/cm³? • Four solid cubes have equal mass. Which occupies the greatest volume? A)Aluminum (density = 2.7 g/cm3) C) Tin (density 7.3 g/cm3) B)Glass (density 3.6 g/cm3) D) Lead (density = 11.4 g/cm3) • A substance is cut into several pieces. As compared to the density of the original sample, the density of each piece will be A) Greater B) Less C) The Same

17. A 5.00 milliliter sample of a substance has a mass of 12.5 grams. What is the mass of a 100 milliliter sample of the same substance? A) 40.0 g B)125 g C)400 g D)250 g • I threw a plastic ball in the pool for my dog to fetch. The mass of the ball was 125 grams. What must the volume be to have a density of 0.500 g/mL. ( I want it to float of course!) • After throwing the ball in the pool for my dog, the ball sprung a leak and began to fill with water. How many mL of water can the ball absorb before the ball sinks? • A little aluminum boat (mass of 14.50 g) has a volume of 450.00 cm3. The boat is place in a small pool of water and carefully filled with pennies. If each penny has a mass of 2.50 g, how many pennies can be added to the boat before it sinks?

18. Compare the densities of the blocks in water

19. Answers

20. Sink or float? • Objects that float in water have a density of _________. • Objects that sink in water have a density of __________. • Objects that “flink” in water have a density of _________. Less than one Greater than one Equal to one

21. If there are 2 graduated cylinders, one filled with alcohol (D=.8611 g/mL) and the other with water . . . • with same mass, compare the volumes. • with same volume, compare the masses. • If there is no balance available, how do we tell which is alcohol and which is water? Alcohol will have the larger volume because it is less dense so it needs to have more space to spread out the particles Water will have more mass because it has a higher density, more tightly packed particles. Find an object that is more dense than alcohol and less dense than water and put into both. It should float in water but sink in alcohol.

22. Place can of Coke and Diet Coke in water • Hypothesis: • What actually happened: • Coke sinks and Diet Coke floats • Why: • Coke has sugar included in the ingredients that makes the density more than one (more particles in same space increases density)

23. Coke held upright in water then opened • Hypothesis: • What actually happened: • Coke stays in can; carbon dioxide leaves the can • Why: • Coke is more dense than water so it will stay below the water; carbon dioxide is less dense than water so it rises above the water

24. Diet Coke placed upright in water and opened • Hypothesis: • What actually happened: • Diet Coke and carbon dioxide both come out of the can • Why: • Diet Coke is less dense than water so it will rise above the water

25. Orange with peel on placed in water • Hypothesis: • What actually happened: • Orange floated • Why: • Orange with peel has a volume larger than its mass to make its density less than one

26. Orange without peel placed in water • Hypothesis: • What actually happened: • Orange sank • Why: • When taking the peel off the volume is decreased drastically while the mass is decreased slightly making the volume less than the mass and the density greater than one

27. Grape in 7-up • Hypothesis: • What actually happened: • Grape sinks then rises to the surface, after a while the grape sinks again • Why: • Grape by itself is more dense than soda, however when the carbon dioxide bubbles attach to the surface of the grape the volume becomes greater making the density of the grape less than the density of the soda

28. Hot and cold water • Hypothesis: • What actually happened: • The hot water (red) was on top and the cold water (blue) was on the bottom • Why: • The particles in hot water are moving faster which causes them to spread out more increasing volume. An increase in volume decreases density making hot water less dense than cold water.

29. Bar of soap in water • Hypothesis: • What actually happened: • All bars of soap sank except the ivory • Why: • Ivory soap is made with air pockets inside making the mass less than other bars of soap of approximately the same size, therefore decreasing the density of Ivory soap.

30. Complete each statement more • 2 objects of same volume, the object with more mass is _______ dense • To make 2 different objects have the same mass, increase the volume of the ______ dense object • 2 objects of same mass, the more dense object has a _______ volume • When keeping volume of a substance the same and increasing mass, density ________ • While keeping mass of a substance the same, if volume is increased then the density is __________ • The relationship between density and volume is ________________ • The relationship between density and mass is ______________ less smaller increases decreased inverse direct