Wednesday, September 24
Tuesday, September 16
Homework
Have your calculator, chemistry binder, and a pen/ pencil
5001
Wednesday, September 17
Homework:
Have your chemistry binder and a pen/ pencil
Matter and Change
Vocabulary
Matter is anything that has mass and takes up space
Matter that has a uniform and definite composition is called a substance
Scenario
Ms. Long told you all to go to the chemistry lab. Once you all arrive, you stumble upon a mysterious white powder. You have no idea what it is or how it got there.
Scenario
Ms. Long told you all to go to the chemistry lab. Once you all arrive, you stumble upon a mysterious white powder. You have no idea what it is or how it got there.
What steps could you take to help you determine the identity of the substance?
Scenario
You take note of the following:
white | Solid at room temperature | Does not melt after twenty minutes on a hot plate | 2.17 g/cm3 | Does not conduct electricity in solid state | Does conduct electricity when dissolved in water |
Scenario
You take note of the following:
Physical Properties of Mystery Substance
white | Solid at room temperature | Does not melt after twenty minutes on a hot plate | 2.17 g/cm3 | Does not conduct electricity in solid state | Does conduct electricity when dissolved in water |
Physical Properties
A physical property is a characteristic that can be observed or measured without changing the identity of the substance
Physical properties
Intensive properties
Extensive properties
Properties of Matter
Intensive properties do not depend on the amount of matter present
Examples - color, hardness, melting point, boiling point, density
Properties of Matter
Extensive properties depend on the amount of matter that is present
Examples - volume, mass, the amount of energy
Extensive Properties vs. Intensive Properties
Extensive Properties (depend on the amount of substance) |
Mass: 39 g Volume: 18.8 cm3 |
Mass: 0.84 g Volume: 4.1 cm3 |
Intensive Properties (independent of the amount of substance) |
Color: Yellow Melting Point: 115.2 ℃ |
Physical Changes
A physical change is a change in a substance that does not involve a change in the identity of the substance
States of Matter - Intensive Property
Solids
Matter in the solid state has definite volume and definite shape
Particles that make up a solid are packed very closely together and are fixed in one position
Liquids
Matter in the liquid state has a definite volume but an indefinite shape
Particles in a liquid move around one another freely
Gas
Matter in the gas state has neither definite volume nor definite shape
As gas particles move, they spread apart, filling the space available
Gas
Vapor describes the gaseous state of a substance that is generally a liquid or solid at room temperature
Chemical Properties
The ability or inability of a substance to combine with or change into one or more other substances is called a chemical property
Example: The white powder isn’t flammable and won’t easily catch fire
A process that involves one or more substances changing into new substances is called a chemical change (chemical reaction)
Mixtures
Mixtures
A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties
Mixture of rocks, sand, iron, and salt
Mixture silver and mercury
What are two types of mixtures?
Vocabulary
Vocabulary
An alloy is a homogeneous mixture of metals, or a mixture of a metal and a nonmetal in which the metal substance is the major component
Vocabulary
Is it homogeneous or heterogeneous?
Salad dressing
Granite
Oolong Tea
Cereal Bar
Soy Sauce
Smog
Is it homogeneous or heterogeneous?
Cereal Bar
Is it homogeneous or heterogeneous?
Cereal Bar
heterogeneous
Is it homogeneous or heterogeneous?
Salad Dressing
Is it homogeneous or heterogeneous?
Salad Dressing
heterogeneous
Is it homogeneous or heterogeneous?
Granite
Is it homogeneous or heterogeneous?
Granite
Heterogeneous
Is it homogeneous or heterogeneous?
Tea
Is it homogeneous or heterogeneous?
Tea
Homogeneous
Is it homogeneous or heterogeneous?
Soy Sauce
Is it homogeneous or heterogeneous?
Soy Sauce
homogeneous
Is it homogeneous or heterogeneous?
Smog
Heterogeneous
Friday, September 19
Modules 1 and 2 Test next Wednesday, September 24
Have your calculator, science binder, and a pen/pencil
Law of Conservation of Mass
During any chemical reaction, the mass of the products is always equal to the mass of the reactants
100.0 g
100.0 g
Law of Conservation of Mass
The law of conservation of mass states that in any physical change or chemical reaction, mass is conserved
Matter is neither created nor destroyed but it can be transformed
System and Surroundings
When studying energy changes, you can define a system as the part of the universe on which you focus your attention
Everything else in the universe makes up the surroundings
Open System | Closed System |
Can exchange both energy and matter with its surroundings | Can exchange only energy with its surroundings, not matter |
Your task
Law of Conservation of Mass Activity - due end of class today
Working in a group of 1-3, read about chemical changes and the law of conservation of mass. Then you and your team will design a closed system to carry out the reaction of baking soda and vinegar.
Friday, September 19
Modules 1 and 2 Test on Wednesday, September 24
Wednesday, September 13
Have your Computer, Density Lab Worksheet, and Science Folder with you
Procedure Example
1. Measure the penny.
1. Measure the penny.
2. Drop the penny in the water.
1. Measure the penny.
2. Drop the penny in the water.
3. Measure how much the water rose up.
1. Measure the penny.
2. Drop the penny in the water.
3. Measure how much the water rose up.
4. Record this in Data Table 1.
1. Measure the penny.
2. Drop the penny in the water.
3. Measure how much the water rose up.
4. Record this in Data Table 1.
5. Use these values to find the density of the penny.
1. Measure the penny.
2. Drop the penny in the water.
3. Measure how much the water rose up.
4. Record this in Data Table 1.
5. Use these values to find the density of the penny.
6. Record this in Data Table 1.
1. Measure the penny.
2. Drop the penny in the water.
3. Measure how much the water rose up.
4. Record this in Data Table 1.
5. Use these values to find the density of the penny.
6. Record this in Data Table 1.
-How would you score this procedure on a scale of 0-6 (0 being the lowest and 6 being the highest)?
-Provide feedback for this procedure and explain why you gave the score you gave.
Friday, September 15
Homework:
Matter Review
Read through these slides on your own and take notes.
Review
In your science notebooks, draw the solids, liquids, gases Venn diagram. Write the letters of each description in the region of the Venn diagram where they belong.
Answers
A
B
C
D
E
F
G
H
I
J
L
K
M
What is matter made of?
Elements
Compounds
Carbon dioxide
Water
Molecules
Carbon dioxide
Water
Mixtures
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
Think of each circle as an ATOM
Now let’s put the atoms into groups based on color
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
atom
Think of each colored group as an Element.
Elements are made of one type of atom.
ELEMENT
ELEMENT
ELEMENT
ELEMENT
There are only 118 Elements that have been discovered so far
Which of the following is NOT an element?
A. C.
B. D.
Which of the following is NOT an element?
A. C.
B. D.
If this is NOT an element, then what is it?
Because this substance contains two or more atoms that are chemically combined, it is a compound.
A molecule is formed when two or more atoms are chemically joined together
MOLECULE
MOLECULE
MOLECULE
MOLECULE
There are two different types of molecules
Compound
Element
Compound
Element
A mixture contains two or more substances that are not chemically combined.
Mixture of Elements |
|
Mixture of Compounds |
|
Mixture of Elements and Compounds | |
|
Elements, Compounds, and Mixtures Key
Compounds and Mixtures
Compounds
Compounds
Properties of Compounds
Compound | Component Elements | |
Water: stable compound, liquid at room temperature | Hydrogen and Oxygen: colorless, odorless gases that undergo vigorous chemical reactions with many elements |
Properties of Compounds
Example: Sodium Chloride vs. Sodium and Chlorine
Properties of Compounds
Example: Sodium Chloride vs. Sodium and Chlorine
Law of Definite Proportions
Law of Definite Proportions
Example - The compound sucrose (also called granulated sugar) is made of carbon, hydrogen, and oxygen. The analysis of 20.00 g of sucrose from a bag of granulated sugar is given below. Note that the sum of the individual masses of the elements found in the sugar equals 20.00 g, which is the amount of the granulated sugar that was analyzed. This demonstrates the law of conservation of mass as applied to compounds: the mass of a compound is equal to the sum of the masses of the elements that make up the compound.
| 20.00 g of Sucrose | |
Element | Analysis by Mass (g) | Percent by Mass (%) |
Carbon | 8.44 | |
Hydrogen | 1.30 | |
Oxygen | 10.26 | |
Total | 20.00 | |
Suppose you analyzed 500.0 g of sucrose from a sample of sugarcane. The percent-by-mass values for the sugarcane are equal to the values obtained for the granulated sugar. According to the law of definite proportions, samples of a compound from any source must have the same mass proportions.
| 20.00 g of Sucrose | 500.0 g of Sugarcane | ||
Element | Analysis by Mass (g) | Percent by Mass (%) | Analysis by Mass (g) | Percent by Mass (%) |
Carbon | 8.44 | | 211.0 | |
Hydrogen | 1.30 | | 32.5 | |
Oxygen | 10.26 | | 256.5 | |
Total | 20.00 | | 500.0 | |
Practice
Law of Multiple Proportions
Law of Multiple Proportions
Copper (Cu) reacts with chlorine (Cl) under different sets of conditions to form two different compounds. The table below provides an analysis of their compositions.
Compound | % Cu | % Cl | Mass Cu (g) in 100.0 g of Compound | Mass Cl (g) in 100.0 g of Compound | Mass Ratio (mass Cu / mass Cl) |
I | 64.20 | 35.80 | | | |
II | 47.27 | 52.73 | | | |
Mass ratio of Compound I
Mass ratio of Compound II
=
Law of Multiple Proportions
These compounds are called copper (I) chloride and copper (II) chloride. As the law of multiple proportions states, the different masses of copper that combine with a fixed mass of chlorine in the two different copper compounds can be expressed as a small whole-number ratio. In this case, the ratio is 2:1.
Compound |
I |
II |
Mass ratio of Compound I
Mass ratio of Compound II
=
2.000
Practice
3. Complete the table. Then analyze the data to determine if Compounds I and II are the same compound. If the compounds are different, use the law of multiple proportions to show the relationship between them.
Compound | Total Mass (g) | Mass Fe (g) | Mass O (g) | Mass Percent Fe | Mass Percent O |
I | 75.00 | 52.46 | 22.54 | | |
II | 56.00 | 43.53 | 12.47 | | |
Compounds
?
Compounds
?
Compounds
?
But HOW??
Compounds
?
Compounds
Compounds
Compounds
Wednesday, September 27
Find your group members from yesterday and answer these questions together.
1. Was the mixture in the lab a heterogeneous mixture or a homogeneous mixture? Explain.
2. How were you able to separate the sand? Explain why the properties of sand allowed you to do this?
3. How were you able to separate the salt and water? What equipment was used?
4. In the solution of salt and water, which is the solute and which is the solvent? Explain.
5. How could you separate a solution of ethanol (a type of alcohol) and water?
Wednesday, September 25
Homework
How Will Your Team Separate the Different Mixture Components?
How Will Your Team Separate the Different Mixture Components?
How can we separate mixtures?
Distillation
Evaporation
Filtration
Magnetic Attraction
Chromatography
Chromatography separates the components of a mixture dissolved in either a gas or a liquid (called the mobile phase) based on the ability of each component to travel or be drawn across the surface of a fixed substrate (called the stationary phase)
Homogeneous and Heterogeneous
How would you separate a mixture of mercury and silver?
Pure Substances
Pure Substances
Elements and Compounds
Elements and Compounds Review
Chemical Change
Distinguishing Substances and Mixtures Review
Symbols and Formulas
The Periodic Table - A Preview
The Periodic Table - A Preview
The Periodic Table - A Preview
Chemical Reactions
Chemical Changes
Chemical Changes
Chemical Changes
Recognizing Chemical Changes
Recognizing Chemical Changes
Recognizing Chemical Changes
Recognizing Chemical Changes
Recognizing Chemical Changes
Friday, September 1, 2023
Wednesday, September 3, 2025
Homework:
Have your calculators, computers, and a writing utensil
Friday, September 5
Homework:
Have your computer and a writing utensil
You will NOT need your calculator today
You want to know how the projectile angle affects the displacement of an object.
You follow the procedure below:
Identify the independent variable.
Identify the dependent variable.
Identify a controlled variable.
Your task
Complete the assignment titled Fundamentals of Experimental Design on Google Classroom.
We will go over the answers together.
Let’s go to the lab
You may choose your lab group members (groups of 1-3) but everyone will complete his or her own lab worksheet. Please bring one device per group.
Post-lab questions
1. The less salty the surrounding water, the faster the ice cube will melt. Discussion of data (2)
As the ice cube melts in the freshwater, the cold melt water from the ice cube sinks to the bottom of the beaker because it is more dense than the freshwater solution. (1) This forces the warmer, less dense water from the bottom of the beaker to move toward the surface (1). The warmer, less dense water transfers heat to the ice cube, causing it to melt faster. (1)
Meanwhile in the saltwater, the cold freshwater from the ice cube floats on top (1) of the saltwater because the saltwater is more dense. (1) Thus the ice cube sits in a pool of cold water, blocking the heat from the saltwater from getting to the ice cube. (1) The evidence becomes more obvious with colored ice.
What should be done in the following situations?
What should be done in the following situations?
What should be done in the following situations?
What should be done in the following situations?
How should the chemicals in the well plate be disposed?
What should be done in the following situations?
How should the chemicals in the well plate be disposed?
What should be done in the following situations?
How should the chemicals in the well plate be disposed?
What should be done in the following situations?
How should the chemical in the beaker be disposed?
What should be done in the following situations?
How should the chemical in the beaker be disposed?
What should be done in the following situations?
How should the chemical in the beaker be disposed?
water
What should be done in the following situations?
When heating a test tube, where should the open end of the tube be pointed?
What should be done in the following situations?
When heating a test tube, where should the open end of the tube be pointed?
Away from you and others
Lab Equipment and Lab Safety Activity
Save Dr. Skelly!
This is Dr. Skelly. He’s a friendly biologist about to submit his research to a prestigious journal!
This is Dr. Pollution. He’s Dr. Skelly’s rival!
This is Dr. Skelly. He’s a friendly biologist about to submit his research to a prestigious journal!
Dr. Skelly has been drugged and locked up by none other than his rival, Dr. Pollution!
You, his lab assistants, must help him escape! To distract you from going straight to the police, Dr. Pollution has hidden the code to unlock Dr. Skelly’s restraints on a website. Part of the website has been given to you (how nice of Dr. Pollution). It’s up to you to find the remainder of the website.
https://tinyurl.com/_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Save Dr. Skelly Instructions
Save Dr. Skelly Instructions
https://tinyurl.com/topsecretskellystuffbaadca
https://tinyurl.com/_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Part 1
Part 2
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Part 1 - Name the Lab Equipment
You have been given pictures of different pieces of lab equipment. Each picture has a number 1-12. Write out the name of each piece of lab equipment in the blanks with the corresponding number. If the equipment’s name has two words, omit the space. The final phrase makes up the first part of the website with Dr. Skelly’s information. The final phrase is made up of letters from the lab equipment.
The first one has been done for you.
B
E
A
K
E
R
K
R
1.
2.
3.
4.
5.
6.
The smaller piece (not the larger piece)
7.
8.
9.
10.
11.
12.
test tube
alcohol burner
funnel
hot plate
tongs
coverslip
thermometer
microscope
graduated cylinder
pipet
electronic scale
Part 2 - Multiple Choice Lab Safety Questions
Read through the multiple choice questions and choose the best answer. The letters of the correct answers will give the remaining 6 letters to the website.
4. You are heating a substance in a test tube. Always point the open end of the tube
5. When you finish working with chemicals, biological specimens, and other lab substances, always
6. If an acid is splashed on your skin, wash at once with
___ ___ ___ ___ ___ ___
1 2 3 4 5 6
Measurements and Calculations
Measurements and Calculations
the comparison of an unknown quantity with a known fixed quantity
a mathematical determination of the amount or number of something
Module 1 - The Central Science
Measurements
Pages 11-26
Covid Social Distancing Forms of Measurement
Units
SI units are a standardized system of units used by scientists all around the world
What SI Unit would you use to measure:
The length of a swimming pool?
What SI Unit would you use to measure:
The length of a swimming pool?
Meter (m)
What SI Unit would you use to measure:
The temperature of the water in the swimming pool?
What SI Unit would you use to measure:
The temperature of the water in the swimming pool?
What SI Unit would you use to measure:
The temperature of the water in the swimming pool?
Kelvin (K)
Units of Temperature
What SI Unit would you use to measure:
The volume of the swimming pool?
What SI Unit would you use to measure:
The volume of the swimming pool?
What SI Unit would you use to measure:
The volume of the swimming pool?
Cubic meters (m3)
What SI Unit would you use to measure:
The length of a pencil?
What SI Unit would you use to measure:
The length of a pencil?
Centimeter (cm)
What SI Unit would you use to measure:
The mass of an elephant?
What SI Unit would you use to measure:
The mass of an elephant?
Kilogram (kg)
What SI Unit would you use to measure:
The mass of an elephant?
Kilogram (kg)
What SI Unit would you use to measure:
The density of this piece of wood?
What SI Unit would you use to measure:
The density of this piece of wood?
What SI Unit would you use to measure:
The density of this piece of wood?
What SI Unit would you use to measure:
The density of this piece of wood?
Grams per cubic centimeter (g/cm3)
Units of Density
Density is the ratio of the mass of an object to its volume
Common units of density are grams per cubic centimeter (g/cm3) for solids and grams per milliliter (g/mL) for liquids and gases
What SI Unit would you use to measure:
The amount of energy produced by hydroelectric energy sources in the United States?
What SI Unit would you use to measure:
The amount of energy produced by hydroelectric energy sources in the United States?
Joules
Units of Energy
Units
SI units are a standardized system of units used by scientists all around the world
A base unit is a defined unit in a system of measurement
Units
Prefixes added to SI base units indicate larger or smaller quantities
Derived Units
Quantity | Unit | Derivation |
Area | m2 | |
Volume | m3 | |
Density | g/cm3 | |
Derived Units
Quantity | Unit | Derivation |
Area | m2 | Length x Width |
Volume | m3 | |
Density | g/cm3 | |
Derived Units
Quantity | Unit | Derivation |
Area | m2 | Length x Width |
Volume | m3 | Length x Width x Height |
Density | g/cm3 | |
Derived Units
Quantity | Unit | Derivation |
Area | m2 | Length x Width |
Volume | m3 | Length x Width x Height |
Density | g/cm3 | Mass / Volume |
Numbers Without Units Mean NOTHING
For example:
Numbers Without Units Mean NOTHING
For example:
Instead:
Numbers Without Units Mean NOTHING
Numbers without units will not receive full credit on assignments and tests.
Conversion Factors
One dozen eggs
12 eggs
Conversion Factors
A conversion factor is a ratio of equivalent values having different units
Dimensional Analysis
Dimensional Analysis is a systematic approach to problem solving that uses conversion factors to move, or convert from one unit to another
When using dimensional analysis, a conversion factor must cancel one unit and introduce a new one
Dimensional Analysis Practice
Dimensional Analysis Practice
Dimensional Analysis Practice
Dimensional Analysis Practice
Dimensional Analysis Practice
Dimensional Analysis Practice
But why do we need to show our work like this?!
Grams and Molecules Practice
2. How many molecules of Br2 react with 1.11 x 1020 molecules of F2?
Br2 + 5F2 → 2BrF5
PCl3 + 3H2O → H3PO3 + 3HCl
Dimensional Analysis Practice
2. How many miles will a person run during a 10.0 kilometer race?
Dimensional Analysis Practice
2. How many miles will a person run during a 10.0 kilometer race?
Dimensional Analysis Practice
2. How many miles will a person run during a 10.0 kilometer race?
Dimensional Analysis Practice
2. How many miles will a person run during a 10.0 kilometer race?
Dimensional Analysis Practice
2. How many miles will a person run during a 10.0 kilometer race?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
3. How many seconds are in a day?
Dimensional Analysis Practice
4. As an instructor is preparing for an experiment, he requires 225 g phosphoric acid. The only container readily available is a 150-mL Erlenmeyer flask. Is it large enough to contain the acid, the density of which is 1.83 g/mL?
4. As an instructor is preparing for an experiment, he requires 225 g phosphoric acid. The only container readily available is a 150-mL Erlenmeyer flask. Is it large enough to contain the acid, the density of which is 1.83 g/mL?
225 g
225 g of phosphoric acid (not including the beaker)
____?____ mL of phosphoric acid
Every 1.83 g of phosphoric acid is 1 mL
Dimensional Analysis Practice
4. As an instructor is preparing for an experiment, he requires 225 g phosphoric acid. The only container readily available is a 150-mL Erlenmeyer flask. Is it large enough to contain the acid, the density of which is 1.83 g/mL?
Yes, because the acid's volume will be 122.95 mL
Dimensional Analysis Practice
5. A student averaged 45 miles per hour on a trip. What was the student’s speed in feet per second?
5280 feet = 1 mile
Dimensional Analysis Practice
5. A student averaged 45 miles per hour on a trip. What was the student’s speed in feet per second?
5280 feet = 1 mile
66 feet per second
Extra Practice
A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed?
Extra Practice
A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed?
15.0 g
15.0 g of ethanol (not including the glass bottle)
____?____ mL of ethanol
Extra Practice
A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed?
15.0 g
15.0 g of ethanol (not including the glass bottle)
____?____ mL of ethanol
Every 0.789 g of ethanol is 1 mL
Extra Practice
A student needs 15.0 g of ethanol for an experiment. If the density of ethanol is 0.789 g/mL, how many milliliters of ethanol are needed?
19.0 mL
Tuesday, September 9
Homework:
Uncertainty in Data Google Form Quiz - due Sunday, 9/14 at 11:59 PM
Module 1 and 2 Test on Wednesday, 9/24
Have your calculator, a writing utensil, and your chemistry binder
Extra Practice
A woman has a mass of 115 lb. What is her mass in grams?
Extra Practice
A woman has a mass of 115 lb. What is her mass in grams?
52162.85 grams
Review
#1
#1
#2
What is the mass in grams of 1.00 gal of water? The density of water is 1.00 g/mL.
#2
What is the mass in grams of 1.00 gal of water? The density of water is 1.00 g/mL.
3785.4 g
#3
#3
#4
#4
Extra Practice
Extra Practice
#5
#5
#6
#6
Challenge Question
A doctor is prescribing Drug X to a 72.7 kg patient. The doctor orders 5 milligrams per pound of patient weight of Drug X to be given per dosage. The supply of the drug is a solution, meaning the drug has been dissolved in water (not in pill or tablet form). The density of the solution is 0.9 g/mL. In other words, 1 mL of the solution contains 0.9 g of Drug X.
How many mL of solution need to be given to the patient per dose?
Conversion Factors:
1 kg = 2.2 pounds
1 pound = 0.45 kg
Challenge Question
A doctor is prescribing Drug X to a 72.7 kg patient. The doctor orders 5 milligrams per pound of patient weight of Drug X to be given per dosage. The supply of the drug is a solution, meaning the drug has been dissolved in water (not in pill or tablet form). The density of the solution is 0.9 g/mL. In other words, 1 mL of the solution contains 0.9 g of Drug X.
How many mL of solution need to be given to the patient per dose?
Conversion Factors:
1 kg = 2.2 pounds
1 pound = 0.45 kg
0.889 mL per dose
A doctor is prescribing Drug X to a 72.7 kg patient.
Drug X
72.7 kg patient
The doctor orders 5 milligrams per pound of patient weight of Drug X to be given per dosage.
Drug X
72.7 kg patient
The supply of the drug is a solution, meaning the drug has been dissolved in water (not in pill or tablet form). The density of the solution is 0.9 g/mL. In other words, 1 mL of the solution contains 0.9 g of Drug X.
Drug X in solution form with density of 0.9 g/mL
72.7 kg patient
How many mL of solution need to be given to the patient per dose?
Drug X in solution form with density of 0.9 g/mL
72.7 kg patient
A doctor is prescribing Drug X to a 72.7 kg patient. The doctor orders 5 milligrams per pound of patient weight of Drug X to be given per dosage. The supply of the drug is a solution, meaning the drug has been dissolved in water (not in pill or tablet form). The density of the solution is 0.9 g/mL. In other words, 1 mL of the solution contains 0.9 g of Drug X.
How many mL of solution need to be given to the patient per dose?
Conversion Factors:
1 kg = 2.2 pounds
1 pound = 0.45 kg
Measurements and Uncertainty in Data
In science, we spend a lot of time dealing with huge numbers…
Distance from earth to closest star outside our solar system
39,900,000,000,000 kilometers
https://www.bbc.com/news/science-environment-37167390
…and tiny numbers
The mass of an electron
0.000000000000000000000000000000910938356 kilograms
Another Example:
The Hope Diamond is the world’s largest deep-blue diamond. This diamond contains 460,000,000,000,000,000,000,000 atoms of carbon.
The Hope Diamond is the world’s largest deep-blue diamond. This diamond contains 460,000,000,000,000,000,000,000 atoms of carbon.
Carbon
460,000,000,000,000,000,000,000 of me!!!
The Hope Diamond is the world’s largest deep-blue diamond. This diamond contains 460,000,000,000,000,000,000,000 atoms of carbon. Each of these carbon atoms has a mass of 0.00000000000000000000002 g.
Carbon
Mass = 0.00000000000000000000002 g
460,000,000,000,000,000,000,000 of me!!!
The Hope Diamond is the world’s largest deep-blue diamond. This diamond contains 460,000,000,000,000,000,000,000 atoms of carbon. Each of these carbon atoms has a mass of 0.00000000000000000000002 g.
If you were to use these numbers to calculate the mass of the Hope Diamond, you would find that the zeros get in your way.
Scientific notation is a shorthand way to write numbers that are really big and really small.
Carbon atoms in the Hope Diamond = 4.6 x 1023 carbon atoms
Mass of one carbon atom = 2 x 10-23 grams
Scientific Notation
Scientific Notation Practice
Value | Scientific Notation | Number of Significant Figures |
0.0259 | | |
902 | | |
55820 | | |
0.315 | | |
0.00973 | | |
10006 | | |
856 | | |
Scientific Notation Practice
Value | Scientific Notation | Number of Significant Figures |
0.0259 | 2.59 x 10-2 | |
902 | 9.02 x 102 | |
55820 | 5.582 x 104 | |
0.315 | 3.15 x 10-1 | |
0.00973 | 9.73 x 10-3 | |
10006 | 1.0006 x 104 | |
856 | 8.56 x 102 | |
Scientific Notation
Scientific Notation Practice
Value | Scientific Notation | Number of Significant Figures |
0.0259 | 2.59 x 10-2 | 3 |
902 | 9.02 x 102 | |
55820 | 5.582 x 104 | |
0.315 | 3.15 x 10-1 | |
0.00973 | 9.73 x 10-3 | |
10006 | 1.0006 x 104 | |
856 | 8.56 x 102 | |
Scientific Notation
Scientific Notation Practice
Value | Scientific Notation | Number of Significant Figures |
0.0259 | 2.59 x 10-2 | 3 |
902 | 9.02 x 102 | 3 |
55820 | 5.582 x 104 | 4 |
0.315 | 3.15 x 10-1 | 3 |
0.00973 | 9.73 x 10-3 | 3 |
10006 | 1.0006 x 104 | 5 |
856 | 8.56 x 102 | 3 |
Scientific Notation
Example -
0.00012 mm = 1.2 x 10-4 mm
Mathematical Operations Using Scientific Notation
Example #1 -
Mathematical Operations Using Scientific Notation
Example #1 -
Example #2 - Determine the total amounts of energy produced by renewable energy sources in the United States
Total:
Hydroelectric | 2.643 x 1018 J |
Biomass | 4.042 x 1018 J |
Geothermal | 3.89 x 1017 J |
Wind | 5.44 x 10 17 J |
Solar | 7.8 x 1016 J |
Example #2 - Determine the total amounts of energy produced by renewable energy sources in the United States
Total:
Hydroelectric | 2.643 x 1018 J | 2.643 x 1018 J |
Biomass | 4.042 x 1018 J | 4.042 x 1018 J |
Geothermal | 3.89 x 1017 J | 0.389 x 1018 J |
Wind | 5.44 x 10 17 J | 0.544 x 10 18 J |
Solar | 7.8 x 1016 J | 0.078 x 1018 J |
Example #2 - Determine the total amounts of energy produced by renewable energy sources in the United States
Total: 7.696 x 1018 J
Hydroelectric | 2.643 x 1018 J | 2.643 x 1018 J |
Biomass | 4.042 x 1018 J | 4.042 x 1018 J |
Geothermal | 3.89 x 1017 J | 0.389 x 1018 J |
Wind | 5.44 x 10 17 J | 0.544 x 10 18 J |
Solar | 7.8 x 1016 J | 0.078 x 1018 J |
Wednesday, September 10
Homework:
Uncertainty in Data Google Form Quiz - due Sunday, 9/14 at 11:59 PM
Module 1 and 2 Test on Wednesday, 9/24
Have your calculator, a writing utensil, chemistry binder, and computer
Mathematical Operations Using Scientific Notation
Example -
(5.23 x 106 mm) x (7.1 x 10-2 mm) = ?
Mathematical Operations Using Scientific Notation
Example -
(5.23 x 106 mm) x (7.1 x 10-2 mm) = ?
(5.23 x 7.1) x (106 mm x 10-2 mm)
= 37.133 x 104 mm2 = 3.7 x 105 mm2
Mathematical Operations Using Scientific Notation
Example -
Mathematical Operations Using Scientific Notation
Example -
= 0.6716049383 x 103 g/mL = 6.7 x 102 g/mL
Practice Questions: Solve the following problems.
Guess the Age
Guess the Age
Guess how old Alfonso Ribeiro is
Guess the Age
Guess how old Alfonso Ribeiro is
53 years old
Guess the Age
Guess how old Alfonso Ribeiro is
53 years old
Guesses close to 53 years old are more accurate than those that are farther
Accuracy and Precision
Accuracy refers to how close a measured value is to an accepted value
Precision refers to how close a series of measurements are to one another
You were given a solution with an unknown volume. Which piece of lab equipment should you use to find the volume: 100 mL beaker or 100 mL graduated cylinder?
You were given a solution with an unknown volume. Which piece of lab equipment should you use to find the volume: 100 mL beaker or 100 mL graduated cylinder?
You were given a solution with an unknown volume. Which piece of lab equipment should you use to find the volume: 100 mL beaker or 100 mL graduated cylinder?
A graduated cylinder is regularly used for measuring volume and is considered more accurate than a beaker because the graduated cylinder has permanently-marked increments (more lines of measurement)
Error
%
%
Percentage Error Practice
Percentage Error Practice
7.69%
What are some examples of sources of error in #1?
What are some examples of sources of error in #1?
Water and a variety of solvents can expand or contract, depending on the temperature
What are some examples of sources of error in #1?
Contaminated glassware or a contaminant in a substance would no longer make the substance pure
What are some examples of sources of error in #1?
Limitations of measuring instruments
Percentage Error Practice
Percentage Error Practice
2.65%
Error in Measurement
What is the length of the object pictured on the right?
Error in Measurement
Significant Figures
Significant Figures
You have a graduated cylinder that contains a liquid. Write the volume of the liquid, in millimeters, using the proper number of significant figures.
Significant Figures
You have a graduated cylinder that contains a liquid. Write the volume of the liquid, in millimeters, using the proper number of significant figures.
The volume in the cylinder is 19.5 mL.
Significant Figures
You have a graduated cylinder that contains a liquid. Write the volume of the liquid, in millimeters, using the proper number of significant figures.
The volume in the cylinder is 19.5 mL.
Estimated digit
Known digit
Known digit
Significant Figures
You have a graduated cylinder that contains a liquid. Write the volume of the liquid, in millimeters, using the proper number of significant figures.
The volume in the cylinder is 19.5 mL.
Volumes in the graduated cylinder can be read with certainty to 1 mL, and with some uncertainty to 0.1 mL, so this measurement has 3 significant figures
Significant Figures
You place an object on a scale and read the mass in grams according to the picture. How many significant figures are in this measurement?
Significant Figures
You place an object on a scale and read the mass in grams according to the picture. How many significant figures are in this measurement?
The mass 21.427 g has five significant figures
Significant Figures
Rules for Significant Figures
2. All final zeros to the right of the decimal place are significant.
Rules for Significant Figures
2. All final zeros to the right of the decimal place are significant.
Rules for Significant Figures
3. Any zero between significant figures is significant.
Rules for Significant Figures
3. Any zero between significant figures is significant.
Rules for Significant Figures
4. Placeholder zeros are not significant. To remove placeholder zeros, rewrite the number in scientific notation.
Rules for Significant Figures
4. Placeholder zeros are not significant. To remove placeholder zeros, rewrite the number in scientific notation.
Rules for Significant Figures
5. Counting numbers and defined constants have an infinite number of significant figures.
Significant Figures Practice
Friday, September 12
Homework:
Uncertainty in Data Google Form Quiz - due Sunday, 9/14 at 11:59 PM
Density Lab - due next Friday 9/19 start of class (hand in)
Module 1 and 2 Test on Wednesday, 9/24
Have your calculator, a writing utensil, chemistry binder, and computer
Significant Figures and
Rounding Numbers
What is the point of significant figures?
What is the point of significant figures?
What is the point of significant figures?
Most of the math that we do in science is with numbers that are measurements
Some measurements are precise, and some are not so precise
For example:
rock
You want to know the mass of this rock.
rock
Scale #1:
$10 USD
rock
Scale #1:
82 g
Scale #1:
82 g
Scale #1:
Lab Equipment #2:
$2000 USD
82 g
Scale #1:
Lab Equipment #2:
82 g
82.1039 g
Scale #1:
Lab Equipment #2:
82 g
82.1039 g
Scale #1:
Now you want to calculate the density of the rock.
Scale #2:
82 g
82.1039 g
Scale #1:
You use the mass from Scale #1 to help you find the rock’s density.
82 g
Scale #1:
82 g
You used a beaker to find the volume of the rock and measured 42 mL
Scale #1:
Now you want to calculate the density of the rock.
82 g / 42 mL =
Scale #1:
Now you want to calculate the density of the rock.
82 g / 42 mL = 1.952380952 g/mL
Scale #1:
Now you want to calculate the density of the rock.
82 g / 42 mL = 1.952380952 g/mL
This value looks so precise - like it only could have been measured with super expensive, precise equipment
Scale #1:
Now you want to calculate the density of the rock.
82 g / 42 mL = 1.952380952 g/mL
So instead, the answer should not be more precise than what we started with
Scale #1:
Now you want to calculate the density of the rock.
82 g / 42 mL = 2.0 g/mL
Now the answer is just as precise as what we started with
Scale #2:
82.1039 g / 42.9338572 mL = 1.91233511 g/mL
On the other hand, if we measured with super sensitive equipment, it would make sense to get an answer that is very precise
82.1039 g
Practice Questions
Complete the practice questions individually. We will go over the first page together. The answers to the second page are posted on Google Classroom for you to check your work.
Rounding Numbers
Rounding Numbers Example
Rules for Rounding Numbers
Rules for Rounding Numbers
2. If the digit to the right of the last significant figure is less than 5, do not change the last significant figure
Rules for Rounding Numbers
3. If the digits to the right of the last significant figure are a 5 followed by a nonzero digit or no other number at all, round up the last significant figure
Rounding Numbers (cont.)
Example -
Rounding Numbers (cont.)
Example -
Rounding Numbers (cont.)
Example -
Rounding Numbers (cont.)
Example -
Significant Figures Practice
Significant Figures Practice
451 cm
101 cm
Br2 is a(n) ________________
Thursday, September 21
Work Day
Homework:
Module 1-2 Test on Monday, September 25
Friday, September 22
Homework:
Module 1-2 Test on Monday, September 25
Friday, September 22
Lab Safety
Saturday, September 23
Homework:
Module 1-2 Test on Monday, September 25
Wednesday, November 1
Jeopardy Review
Tomorrow: more review
Midterm on Monday
Jeopardy Instructions
#6
Which of the following must remain constant in the following closed system - a sealed bottle of soda taken out of the refrigerator