DEDUCING DENSITY

HYPOTHESIS

Will an object that floats in water float in all liquids? What has this got to do with density?

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MATERIALS & EQUIPMENT

1 beaker
4 mystery liquids
5 small paper cups
3-4 small objects
water

LAB SAFETY AND PROTOCOL

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PROCEDURE

Label four of the paper cups with the letters A-D.
Fill each cup with the mystery liquid corresponding to the letter.
Observe each liquid and try to guess what it is. You can shake it, tip it, smell it and so on but do not taste it or feel it. Record your guess and the physical properties that led you to make this guess in Table A at the end of the write up.
To calculate the actual density of each liquid, you'd have to know its volume and weight. See if you can deduce the relative density of each liquid from its physical properties. List the liquids in order in Table B at the end of the write up.
Predict what will happen when you slowly pour all four liquids into a jar, one at a time. Will they mix? Will they make layers? Where will each of the liquids end up? Sketch your prediction.
Decide which liquid to pour in first, second, third and last. Write the order here: ___________________________
Now do it! Make your brew by pouring each liquid slowly down the side of the jar.
What happened? Did any of the liquids switch places? Did they mix together? How was your prediction?

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Draw the actual results above.
Fill the remaining cup with water.
Try dropping a variety of small objects in the water. Note whether they sink or float.
Now drop them in your brew and record where they end up (use Table C at the end of the write up).

CONCLUSION

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CHALLENGE

Can you use your results from dropping small objects in your brew to figure out which mystery liquids are more dense than water? less dense than water?

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TABLE A: Physical Properties Of Mystery Liquids
SAMPLE	PHYSICAL PROPERTIES	GUESS
A
B
C
D

TABLE B: Deduced Density Of Mystery Liquids
DENSITY	SAMPLE
Greatest Density


Lowest Density

TABLE C: Small Objects In Liquid
OBJECT	FLOATS IN WATER?	ENDS UP BETWEEN LAYERS
		and
		and
		and
		and

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