catalyst

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Catalyst 1. If I have a can of coke and I put it in a bowl of water, will it sink or float? What about a can of diet coke? 2. Convert 3 mL to ounces 3. A scientist wants to test his hypothesis: If I use fertilizer on my lawn every day then my grass will grow taller because it’s receiving more nutrients 1. Write a scientific question and identify the independent variable, dependent variable, control and constants

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Catalyst. If I have a can of coke and I put it in a bowl of water, will it sink or float? What about a can of diet coke? Convert 3 mL to ounces - PowerPoint PPT Presentation

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Page 1: Catalyst

Catalyst

1. If I have a can of coke and I put it in a bowl of water, will it sink or float? What about a can of diet coke?

2. Convert 3 mL to ounces

3. A scientist wants to test his hypothesis: If I use fertilizer on my lawn every day then my grass will grow taller because it’s receiving more nutrients

1. Write a scientific question and identify the independent variable, dependent variable, control and constants

Page 2: Catalyst

Objectives

SWBAT calculate the density of objects by using measured mass and volume

SWBAT compare densities of various objects

Page 3: Catalyst

Agenda

1. Teacher demos

2. Density Lecture

3. Density Essential Lab Activity

4. Calculate Densities Measured

5. Precision vs Accuracy

6. Lab Results and Conclusions

Page 4: Catalyst

Which floats, Coke or diet Coke?

Page 5: Catalyst

Apply it to real life:

More sugar Less sugar

What makes Coke different from diet Coke?

Page 6: Catalyst

So what can we conclude about density?

More dense = sink Less dense = float

Page 7: Catalyst

Definition of Density

Density: the amount of matter per unit of space of an object

But what does that really mean?

Page 8: Catalyst

Compare Thing 1 and Thing 2

Thing 1 Thing 2

Which of these has more matter? Which has more space?So which one is the most dense?

Page 9: Catalyst

Compare Thing 1 and Thing 2

Thing 1 Thing 2

Matter/

Matter/ Space SpaceLess

dense

More dense

Page 10: Catalyst

Definition of Density

Density: the amount of matter per unit of space of an object

But what does that really mean?How compact or packed together the

matter is in the space of an object.This is a property of matter that does not

change with the amount of the object

Page 11: Catalyst

Compare Thing 3 and Thing 4

Thing 3 Thing 4

Which of these has more matter? Which has more space?So which one is the most dense?

More dense

Less dense

Page 12: Catalyst

Liquid Layers – Check it out!

Which liquid has the highest density?

Which liquid has the lowest density?

Which liquid has the middle density?

Can you tell the density of something by looking at it?

Page 13: Catalyst

Definition of Density

Density: the amount of matter per unit of space of an object

Matter: per: Space:

Mass Volume

Page 14: Catalyst

Formula for Density

D = m = mass = g or g

V volume mL cm3

Tools: scaleand ruler/graduated

cylinder

Page 15: Catalyst

Density Lab and Sample Calculations

Rotate around the room and visit each of the 5 Stations At each station, you will find instructions on what to do along with some questions.

After taking all necessary measurements and answering the questions at the station, rotate to the next station. Note: Do not calculate the density, we will do that as a class

Once you have visited every station, return to your seat.

Page 16: Catalyst

Density Lab and Sample Calculations

What is your data obtained for water? What is your volume? What is the mass? What is the density of water?

Page 17: Catalyst

Density Lab and Sample Calculations

What is your density for the water?

Page 18: Catalyst

Precision vs Accuracy

Precision = how close measurements are to each other

Accuracy =how close the measurements are to the “true” value

Page 19: Catalyst

Density Lab and Sample Calculations

Now calculate the densities for each of the stations in your lab composition book

Page 20: Catalyst

Density Lab Observation Questions

Answer the following questions in your lab notebook:What is the density determined for your water sample?What could you do to improve the accuracy of your measurements? How does the density of the weight compare to the density of water? Which is denser?Nickel (metal) has a density of 8.91 g/mL. Compare this to the density of the nickel coin you calculated. Is the nickel coin made of pure nickel (metal)?

Page 21: Catalyst

Density Lab Conclusion Questions

Answer the following questions in your lab notebook:

1.When you use the terms heavier or lighter to compare different objects with the same volume, what property of the objects are you actually comparing?

2.Would you expect the densities of various fruit juices in the same container to all be the same? Explain.

3.How can the concept of density be used to differentiate between a genuine diamond and an imitation diamond?

4.The density of aluminum is 2.70 g/cm3. What volume will 13.5 grams of aluminum occupy? HINT, use unit conversion!

Page 22: Catalyst

Homework # 2: Due Next Class

Homework can also be downloaded from the class website1.What is the density of 10 g of a metal if the metal raises the level of water in a graduated cylinder from 25 mL to 45 mL?

2.What is the density if 50 g of a metal occupies a volume of 5 cm3?

3.If you were trying to test whether Advil or Tylenol reduced fevers more, write a problem statement, hypothesis and variables for an experiment you could perform.

Page 23: Catalyst

lecturePLUS Timberlake 23

Problem 1

Osmium is a very dense metal. What is its

density if 50.00 g of the metal occupies

a volume of 2.22 cm3?

Page 24: Catalyst

lecturePLUS Timberlake 24

Solution

D = mass = 50.00 g = volume2.22 cm3

= 22.522522 g/cm3 = 22.5 g/cm3

Page 25: Catalyst

lecturePLUS Timberlake 25

Problem

What is the density of 48 g of a metal if the metal raises the level of water in a graduated cylinder from 25 mL to 33 mL?

33 mL

25 mL

Page 26: Catalyst

lecturePLUS Timberlake 26

Solution

Volume (mL) of water displaced = 33 mL - 25 mL = 8 mL

D = mass = 48 g = volume 8 mL

= 6 g/mL