Density

Eric Angat Teacher

250 mL. Beaker ( volume in mL.)

Graduated cylinder ( volume in mL.)

Digital balance ( mass is grams )

Ruler (length in cm. or centimeter)

400-450 mL.

50 mL./ 5= 10 mL.

for each line

Reading the Graduated cylinder correctly Read from the lower meniscus at eye level.

Using the digital balance 1. Turn on the digital balance by pressing the 2. Make sure the unit is in g or grams. If not, press the button on the left once.

Reminders: 1. Follows instructions.

2. Formulate your hypothesis.

3. Record all observations. You can take pictures or recordings of your experiment using your devices.

4. Identify the parts of the experiment.

5. Make valid or objective conclusions.

Gropuping: 1. choose the

leader

of the group.

2. Choose a

secretary

or recorder.

3. Choose who will be

performing the steps

, together with the leader.

4. Choose one to

take pictures

.

5. Choose who will

clean up

after the experiment.

Merits

and

Demerits

• Did all steps accurately +2 • Did all steps accurately without accidents +5 •

Spilled water-5

•

Spilled salt-5

•

Dropped apparatus -10

I. Investigative Question:

How do I calculate the density of an object?

II.Hypothesis: If I ______ then _______ because __________.

• • • • • • • • • • • III. Materials: Jenga block 250 mL. graduated cylinder 50 mL. graduated cylinder 50 mL. beaker 100g metal weight Medicine dropper Candle Plastic bread knife Plastic spoon Permanent marker Ruler or tape measure

VI. Experimental design A. Calculate the density of water.

1. Weigh and Record the mass of the 250 mL.

graduated cylinder.

2. Pour 100 mL. of water into the 250 mL.

graduated cylinder.

3. Weigh and record the mass of the 250 mL.

graduated cylinder with 100 mL. water.

Experimental design A. Calculate the density of water.

Mass of the graduated cylinder with 100 mL. water A Mass of the graduated cylinder B Mass of water ( C=A-B ) C Volume of water in the 250 mL.

graduated cylinder D Density of water Mass of water/ Volume of water

Experimental design B. Calculate the density of saltwater.

1. Weigh and record the mass of the 250 mL.

graduated cylinder.

2. Fill the 250 mL. beaker with 200 mL. of water.

3. Dissolve 30 g of salt to the 200 mL.

water in the beaker.

Experimental design B. Calculate the density of saltwater.

Do not transfer the undissolved salt.

4. Transfer 100 mL. salt solution to the 250 mL. graduated cylinder.

Experimental design B. Calculate the density of saltwater.

5. Weigh and record the mass of the graduated cylinder with 100 mL. saltwater.

6. Subtract the mass of the graduated cylinder from the mass of the graduated cylinder with 100 mL. saltwater.

Experimental design B. Calculate the density of saltwater.

7. Calculate the density of the saltwater by using the equation Density = mass of saltwater / volume of saltwater.

Experimental design B. Calculate the density of saltwater.

Mass of the graduated cylinder with 100 saltwater mL. water A Mass of the graduated cylinder B Mass of saltwater ( C=A-B ) C Volume of water in the 250 mL.

graduated cylinder Density of saltwater Mass of saltwater/ Volume of water D

Experimental design C. Determining the density of the Jenga block.

1. Weigh and record the mass of the Jenga block.

2. Measure and record the length of the Jenga block.

3. Measure and record the width of the Jenga block.

4. Measure and record the height of the Jenga block.

Experimental design C. Calculate the density of the Jenga block.

Mass of the Jenga block A Length of the Jenga block (l) Width of the Jenga block (w) Height of the Jenga block (h) Volume of Jenga block V = l x w x h Density of jenga block Density = Mass of Jenga block/volume of Jenga block

Experimental design D. Determining the density of an irregular solid using water displacement method.

1. Determine the volume of

100 g

irregular solid.

2. Pour 200 mL.

water into a 250 mL. graduated cylinder. 3. Carefully drop the 100g weight into the water and record the

new volume

.

Experimental design D. Calculate the density of irregular solid using water displacement method.

Mass of the 100g weight Original volume of water A B New volume of water C Amount of water displaced in mL.

(D=C-B) D Density of irregular solid Density = mass/volume Density = A/D

100 g

Experimental design E. Comparing densities.

1. Pour 350 mL.

water into the 500 mL.

graduated cylinder. 2. Carefully drop the Jenga block in the water. 3. Record the new volume after dropping the Jenga block in the water in table F.

3. How much of the Jenga block sunk?

Experimental design E. Interpreting results

Density of water from Table A Density of wooden block from Table C Why did the wooden block float?

g/mL.

g/mL.

___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________ ___________________________________________________

Experimental design F. Interpreting results

Original volume of water in mL.

New volume of water in mL.

Increase in the volume of water after dropping the Jenga block.

(C=B-A) How many grams is the volume in column C 1g = 1 mL Mass of the Jenga block A B C D E

350 mL.

______ milliliters or mL.

______ milliliters or mL.

______ grams.

Research!

What can you say about Archimedes principle?

_____ grams.

_____________________ _____________________ _____________________ _____________________ _____________________

Experimental design G. Mass VS. Density

3

1. Cut a candle into three different lengths.

2

2. Label the candle pieces as 1,2, and 3.

1

Experimental design G. Mass VS. Density 3. Determine and record the mass of each candle using a balance.

Experimental design G. Mass VS. Density 3. Determine the volume of each candle by

water displacement

.

4. Determine the density of each candle by using the equation D=mass/volume

Experimental design G. Mass VS. Density 3.Fill the 250 mL. graduated cylinder with 200 mL. water.

4. Carefully drop the candle in the graduated cylinder.

Experimental design G. Mass VS. Density 5. Record the new volume in the table.

4. Carefully remove the candle and repeat steps 3 5 for the other two candles.

1. Fill the graduated cylinder with 200 mL.

water.

2. Carefully drop the candle in the graduated cylinder.

2. Read and record the new volume of the water.

4. Carefully remove the candle and be sure the volume of the water is still 200 mL.

5. Repeat the steps for the other two candles .

Experimental design G. Recording Data

Mass ( g) Determined by using the balance.

Volume ( mL.) Determined through water displacement.

Candle #1 Candle #2 Candle #3

Density (g/mL.) Mass/volume

Experimental design H. Graphing Data Y -Axis How does the density line compare with the mass and volume line?

___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ ___________________________________________________________________________ 0 X -Axis

Clarifying Questions: Why did the Jenga block float and the 100g weight sink in water?

_________________________________________________________________ _________________________________________________________________ What method did you use to determine the volume of the irregularly shaped solid?

________________________________________________________________ Which is more dense water or saltwater? Explain your answer.

_________________________________________________________________ _________________________________________________________________ How do you calculate the density of an object?

_________________________________________________________________ _________________________________________________________________

Experimental design H. Graphing Data

Experimental design H. Graphing Data Candle #1 Candle #2 Candle #3

Mass ( g)

2 1 0.67

0.33

Density Volume ( mL.)

(g/mL.) 2.985074627

3.03030303

3 1 3