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Outline for a High School Chemistry Class

Need to complete a high school chemistry class with a wet lab? We did and that is how this blog was born. To help you get started, we have put together an overview of a high school chemistry course with links to posts about the lessons and labs.

I. Getting a High School chemistry lab kit.

We chose the The Home Scientist for our hands-on chemistry lab kit.

Of those offered, we used the CK01A Standard/Honors Home School Chemistry Laboratory Kit

The kit comes with most of the equipment and chemicals you need for a high school chemistry wet lab that you can do at home. It also comes with a free .pdf manual to download with complete, extensive lab instructions. (Link on this page). You will have to supply some materials, which are common household items for the most part. You will also need a place to store the chemicals away from small children and pets.

II. Choosing a High School Chemistry Textbook:

The text we used was Introductory Chemistry (4th Edition) by Nivaldo J. Tro. The book the textbook reading assignments in the lessons refer to that text. We chose this text over the Essentials version because it has three additional chapters at the end which could be used as reference material. We used chapters 1-16.

As typical with the textbook industry, there is now a newer edition.

Introductory Chemistry (5th Edition) by Nivaldo J. Tro

We liked the tone of the text and the great illustrations.

Another text that is commonly used in high school chemistry classrooms is:

Chemistry by Steven S. Zumdahl and Susan A. Zumdahl

Want more information? Don’t forget to check the links in the Online Chemistry Textbooks page and our Choosing a Chemistry Textbook post from the beginning of the class, which has more options.

III. High School Chemistry Class Outline

The following are links to the blog posts we used for the class. I split some of the chapters in the Tro text, so we ended up meeting for 22 weeks.

I have left out the sidebars, which were posts about some more information on questions the students found interesting.

Keeping a Chemistry Laboratory Notebook

Lesson 1: Introduction to Chemistry

Lab 1 Density of Liquids: Soft Drinks and Water

Lesson 2: Measurement and Problem Solving

Lab 2 Density of Solids and Measurement Challenge

Lesson 3: Matter

Lab 3: Separation of Mixtures

Lesson 4: Energy

Lab 4: Heat Capacity

Lesson 5: Atoms and Elements

Lab 5: Chemistry Unleashed

Lesson 6: Molecules and Compounds

Lab 6: What we did

Lesson 7: Calculating Chemical Composition

Lab 7: Finding Moles and Molecules

Lesson 8: Chemical Reactions Part 1

Lab 8: From Topic I, Recrystallization and Salting Out

Sidebar: Lab 8 Update

Lesson 9: Classifying Chemical Reactions

Lab 9: Topic III, Classifying Chemical Reactions

Lesson 10: Quantities in Chemical Reactions

Lab 10: Double Displacement Reactions

Lesson 11: The Electromagnetic Spectrum

Lab 11: Photochemistry

Lesson 12: Electrons, Atom Models, and the Periodic Table

(Note: For the lab, we did models of atom orbitals using Model Magic modeling clay. Let me know in the comments if you would like details.)

Lesson 13: Chemical Bonding

Lab 13: Conductance of Ionic and Molecular Solutes

Lesson 14: Gases

Lab 14: Gas Properties and Laws

Lesson 15: Properties of Liquids and Solids

Lab 15: Viscosity and Other Physical Properties of Liquids

Lesson 16: Solutions

Lab 16: Solubility and Solutions

Lesson 17: Acids and Bases

Lab 17: Investigating pH
Lesson 18: Rates of Chemical Reactions

Lab 18: Chemical Kinetics

Lesson 19: More About Rates of Chemical Reactions

Lab 19: Effect of Catalysts on Reactions

Lesson 20: Oxidation and Reduction

Lab 20: Sweet Redox Reactions for National Chemistry Week

Lab 21: Electrochemistry

For Lab 22, we had a review with activities and tasks from throughout the course.

outline-for-high-shcool-chemistry-course-homeschool

If you would like to know more about any of the materials or coursework, please feel free to leave questions in the comments.

Lab 21: Electrochemistry

Experimental Title: Lab 21:  Electrochemistry

Date of laboratory:  October 28, 2014

Purpose: The purpose of this laboratory is to investigate electrolysis of water and to produce electricity via a chemical reaction in a lemon battery.

Introduction:

Electrochemistry is the relationship between chemical energy and electrical energy. If you would like to learn more, be sure to review the second half of chapter 16 in your textbook.

Electrochemistry involves two separate processes:

1. Utilizing electrical energy to cause a chemical reaction to occur. An example is electrolysis, during which electricity is used to split water into oxygen and hydrogen gas.

The reaction for the electrolysis of water is
2H20 → O2 + 2H2

test-tubes

2. Using a chemical reaction to produce electricity. An example is a lemon battery, which can be used to produce enough electricity to light up a LED (Light emitting diode).

Check out this animation showing the movement of electrons between zinc and copper in a galvanic cell (Takes a few seconds to load.) A similar reaction takes place within the lemon.

How to make a lemon battery:

See the Hila Website for more instructions for making a lemon battery.

Special safety concerns for Lab 21:

  • If anything spills, please clean it up immediately with a paper towel and let your instructor know.
  • If glass breaks, do not pick it up with your bare hands. Notify your instructor immediately.
  • Be sure to wash your hands when you are finished with this lab
  • Avoid touching the battery with wet hands and don’t touch both terminals at once to avoid shocks.

Materials:

  • Magnesium sulfate (Epsom salts)
  • 9 Volt battery
  • Battery adapter
  • Glass beaker
  • 2 test tubes
  • Water
  • Graduated cylinders
  • Transfer pipette
  • Rubber band
  • Stoppers
  • Wood splint
  • Matches or butane lighter
  • Lemons
  • Zinc
  • Copper
  • Wires
  • LED (Light emitting diode)
  • Spatula (measuring)

Procedures:

Part 1.  Electrolysis of Water

1. Obtain a 250 mL glass beaker, 9 volt battery,  2 test tubes, magnesium sulfate, a rubber band, and the batter adapter with wire leads.

2. Add about 200 mL of water to the glass beaker. Add a heaping spatula full of magnesium sulfate to the water. Stir until it is dissolved.

3. Place the two glass test tubes side-by-side. Wrap with a rubber band to hold them in place.

4. Over the sink, fill the test tubes with the magnesium sulfate solution, trying to prevent bubbles from forming. Stopper the tubes with rubber stoppers.

5. Invert the tubes into the beaker and remove the stoppers, keeping the tubes submerged. If you have difficulty manipulating the stoppers in the beaker, try putting your thumb over a single filled test tube (like we did last time) and then transfer the tube into the beaker and release so the open end is submerged and no bubbles are trapped in the top. Hold the tube upright and repeat with the second tube.

6. Have a helper hold the tubes while you run the leads of the battery adapter into each test tube, red into one and black into the other. Do not submerse the adapter itself.

7. Connect the 9 volt battery to the adapter part. Pay attention to which ends are in which test tubes.

Observations:

8. Remove the battery when one test tube is filled with gas. Stopper each test tube under water to preserve the gases inside.

Optional:  Take the test tubes outside with the wood splint and lighter. For the tube with less gas in it, light the splint and then blow it out. Place the glowing splint near the opening of the tests tube and release the stopper.

What does this show?

Now, light another splint and hold it near the opening of the test tube with more gas, and remove the stopper. Note:  be prepared for a pop sound, so don’t be startled.

Part 2.  Lemon Battery

We will follow the instructions in the above video and website (linked in the introduction section) to put together and test a lemon battery.

Conclusions:

Once you have completed the parts, sit down and write a sentence or two to explain the results.

Discussion:

Record any thoughts you have about the experiments, including:

  • Possible improvements to the procedures or how to tweak techniques
  • How the results differed from your expectations
  • Suggestions for other experiments

Please leave a comment or send an e-mail if you have any questions before our meeting.

 

Lab 20: Sweet Redox Reactions for National Chemistry Week

In honor of National Chemistry Week 2014, let’s do some redox reactions using something sweet.

Experimental Title: Lab 20: Reduction-Oxidation Reactions

Date of laboratory:  October 21, 2014

Purpose: The purpose of this laboratory is to evaluate redox reactions.

Introduction:

Part 1: Permanganate Changes Color with Oxidation State

Sometimes it is possible to determine the oxidation state of a substance by looking at its color.

In a basic solution with small amounts of sugar added, permanganate ion is reduced to manganate ion:
MnO4– + e → MnO42–
and the solution changes from deep purple to deep green in color.
When there is excess sugar, the manganate is reduced to MnO2.
MnO42– + 2H2O + 2e → MnO2 + 4OH–
MnO2 is yellowish brown at the low concentrations, which is the final color change. This reaction is commonly called the “chameleon reaction” because many intermediate colors are often seen as the reaction progresses.

Here is a video that shows the reaction (you might want to turn down your speakers before playing it).

Part 2. Redox titration to find the relative amount of Vitamin C (ascorbic acid) in different foods

In this reaction, iodine oxidizes ascorbic acid to dehydroascorbic acid as it is reduced to iodide ions.
ascorbic acid + I2 → 2 I− + dehydroascorbic acid

Once all the ascorbic acid has been oxidized, the excess iodine is free to react with the starch indicator, forming the blue-black starch-iodine complex.

Special safety concerns for Lab 20:

  • Please use gloves and eye protection when handling hazardous materials.
  • If an acid spills, cover it with baking soda as we discussed. If a base such as NaOH spills, neutralize it with vinegar. If either spills on your skin, immediately wash with water.
  • If anything else spills, please clean it up immediately with a paper towel and let your instructor know.
  • If glass breaks, do not pick it up with your bare hands. Notify your instructor immediately.
  • Be sure to wash your hands when you are finished with this lab.

Materials:

  • Distilled water
  • Transfer pipettes
  • Sodium hydroxide
  • Sugar (granulated)
  • Glass beaker
  • Potassium permanganate, 0.1 M
  • Plastic cup
  • Starch indicator solution
  • Iodine
  • Orange juice
  • Cranberry juice
  • Red pepper juice
  • Lemon juice
  • Strawberry juice

Procedures:

Part 1. Permanganate Changes Color with Oxidation State

  1. Fill a glass beaker with 100 mL distilled water.
  2. Add 1 small spatula of granulated sugar and mix with stirring rod.
  3. Using the transfer pipette, add 0.5 mL sodium hydroxide.
  4. Using a clean pipette, add 0.5 mL of potassium permanganate.

Observations:

Note:  If the reaction does not proceed completely to yellowish-brown after about 10 minutes, try adding another spatula full of sugar.

 

Part 2. Perform a REDox Titration to Determine the Relative Amounts of Vitamin C (Ascorbic Acid) In Different Foods

1. Add 5 mL of distilled water to a plastic cup. Add 0.5 mL of starch indicator and stir. Draw up iodine in a transfer pipette and add one drop to the solution (Set the filled pipette in a clean cup). Swirl the solution. It should turn blue-black, indicating the presence of iodine. This shows you the color you should achieve at the endpoint of titration. Now add a few mL of orange juice to see what happens.

Observations:

2. Set up empty plastic cups for each type of juice. Predict which juices will contain the most Vitamin C (ascorbic acid) and thus require the most drops of iodine to reach the endpoint (turn blue-black).

Predictions:

Most vitamin C (ascorbic acid): _________________

2nd:__________________

3rd:___________________

4th:____________________

Least vitamin C: _____________

3. Add 5 mL of orange juice to a clean, empty cup. Add 0.5 mL of starch indicator. Draw up iodine into a pipette or use the pipette you filled previously. Carefully add iodine a drop at a time, counting the drops. Swirl after adding each drop and check to see if the solution has reached the titration endpoint (turned blue-black). Once the solution remains blue-black, record the number of drops of iodine you added.

Number of drops:

4. Repeat step 3 for the remaining types of juice.

Number drops for:

  • Cranberry juice:
  • Red pepper juice:
  • Lemon juice:
  • Strawberry juice:

Did your results match your predictions?

lemon

 

Conclusions:

Once you have completed the two parts, sit down and write a sentence or two to explain the results of each part.

Discussion:

Record any thoughts you have about the experiments, including:

  • Possible improvements to the procedures or how to tweak techniques
  • How the results differed from your expectations
  • Suggestions for other experiments
  • What key concepts you learned about redox reactions

Please leave a comment or send an e-mail if you have any questions before our meeting.

Lesson 20: Oxidation and Reduction

Can you believe we are on the last chapter of the textbook already? Our chemistry lessons are flying by.

Textbook Reading: Chapter 16, Oxidation and Reduction on pp. 577- 603, paying particular attention to the Rules for Assigning Oxidation States on page 581.

Oxidation and reduction are fundamental to chemistry, but can be a bit complicated to understand. This is probably why the author introduces them in the final chapter after you have a good understanding of other concepts.

During many chemical reactions, electrons are moved around. When an atom loses electrons, chemists say it has been oxidized. When an atom gains electrons during a reaction, it is said to be reduced.

The first question you might have is why is gaining electrons called reduction. Actually, you have to go back 500 years or so to the foundations of chemistry through alchemy to find out the answer.

Hematite_macle (Image in the public domain from Wikimedia)

When early metal workers melted iron ore, the iron oxides in the ore released oxygen gas and the process resulted in pure iron. Because mass was lost (there was less iron produced that ore used), it was called a reduction.

The chemical equation:

2 Fe2O3 ->  4 Fe (solid) + 3 O2 (gas)

If we consider what is happening to the iron atoms, we realize the Fe ions are gaining electrons to become pure iron metal.

4 Fe+2 + electrons –> 4 Fe0

A few hundred years later, early chemists realized that oxygen was the gas being released and that adding oxygen to metals caused the formation of metal oxides. This led to the idea that the reverse of reduction involved gaining of oxygen, or oxidation.

We now know that oxygen doesn’t have to be involved in oxidation-reduction reactions and that reduction is actually the gain of electrons by atoms, but we are stuck with those historical, relatively-inaccurate names.

All is not lost, however, because chemistry students have come up with some tricks to remembering the terms.

1. This is a common way to remember the terms:

leo-lion(Lion image by Petr Kratochvil at publicdomainpictures.net)

LEO = Loss of Electrons is Oxidation

GER = Gain of Electrons is Reduction

2. Another version is OILRIG , which is short for Oxidation is Loss (of electrons) and Reduction is Gain (of electrons).

3. You may also think of a gain of electrons as increasing a negative charge, or in other words, reducing the charge of the ion to a smaller number.

Why look at Reduction-Oxidation or Redox?

How easily a metal loses electrons will help predict how reactive it is and its behavior when mixed with other elements. Redox states help chemists figure out the likelihood certain reactions will occur.

Another use is to figure out the amount of certain substances in samples by redox titration, similar to acid-base titration. For example, it is possible use a redox titration to find out the amount of vitamin C (ascorbic acid) in different types of food or juice.

Let’s finish up with a discussion of Redox Reactions by Mr. Anderson of Bozeman Science.

Please let me know if you have any questions or comments about oxidation-reduction.

Sidebar: National Chemistry Week 2014

Next week, from Sunday, October 19, 2014 to Saturday, October 25, 2014, is National Chemistry Week.

NCW 2014 - Candy

The theme for 2014 is “The Sweet Side of Chemistry,” a perfect theme for the days leading up to Halloween.

Have you ever wondered what kind of jobs chemists have? Here are three videos from the American Chemical Society that might give you some new ideas.

The Chemistry of Hershey’s shows what goes on behind the scene in the chemistry labs at Hershey’s. Researcher Paula Gibson says there isn’t a “typical day” and she advises that scientists should not be afraid of failure, although they just might have to eat their failures.

Candy Chemistry with Rich Hartel, Ph.D. discusses how the chemical properties of sugar helps define the products that can be made. Peeps jousting anyone?

Ice Cream Chemistry reveals that a job in food science can make you a lot of friends!

Chemistry can take you more places that you might have realized!

Lab 19: Effect of Catalysts on Reactions

Last time we looked at how concentration, temperature and surface area can influence rates of reaction. For this lab, we are going to determine the effects of catalysts on reaction rates.

Reading:  The Home Scientist Lab Topic VI. Session VI-2, pp. 114- 117.

Important note:  we will be using yeast as a source of catalase rather than blood. Please make that change as you write out the procedure in you notebook!

Experimental Title: Lab 19:  Effect of Catalysts on Reaction Rates

Date of laboratory:  October 14, 2014

Purpose: The purpose of this lab is to examine the effects of various catalysts on the rates of reactions.

Introduction:

For this lab, we will speed up the reaction of hydrogen peroxide breaking down into oxygen and water by adding catalase enzyme from yeast. We’ll stop the reaction by adding sulfuric acid to denature the catalase and then titrate the resulting solutions with a dilute solution of potassium permanganate to determine how much unreacted hydrogen peroxide remains in each sample.

In the presence of hydrogen peroxide, MnO4- ions are quickly reduced to Mn2+ ions, and the solution remains a light brown color. As soon as permanganate ions are slightly in excess, the solution assumes a purple color. By determining
the amount of permanganate required to change color, we can calculate the amount of hydrogen peroxide that remains in the samples.

Important equations:
2 H2O2(aq) → 2 H2O(l) + O2(g)

5 H2O2(aq) + 2 MnO4-(aq) + 6 H+(aq) → 2 Mn2+(aq) + 8 H2O(l) + 5 O2(g)

 Hydrogen-peroxide-3D-balls

(Public domain illustration of hydrogen peroxide from Wikimedia)

Special safety concerns for Lab 19:

  • Please use goggles and gloves.
  • If anything spills, please clean it up immediately with a paper towel and let your instructor know.
  • If glass breaks, do not pick it up with your bare hands. Notify your instructor immediately.
  • Be sure to wash your hands when you are finished with this lab

Materials: Include the list on page 114, but substitute yeast for blood.

Procedures:

Write the procedure on pages 115- 116 in your notebooks, substituting “yeast” for blood or “meat juice.”

_____________________

We will also look at a few other catalyzed reactions, but you won’t need to include these in your notebook unless you want to do so.

Materials:
◦    Copper II sulfate solution
◦    Clear plastic cup
◦    Salt
◦    Aluminum foil
◦    Thermometer
◦    Plastic spoon
Procedure:

  1.    Place the piece of aluminum foil in an empty cup. Use your fingers to push the foil firmly down so that it lays flat and covers the bottom of the cup.
  2.     Add 5 mL of the copper II sulfate solution to the cup with the aluminum foil.
  3.     Gently swirl the solution for a few seconds and let it stand still. Watch the aluminum for any bubbling or color change.
  4. Carefully place a thermometer in the cup and record the temperature.
  5.  Use your plastic spoon to place a small amount of salt in the copper II sulfate solution. Gently swirl the solution for a few seconds and let it stand still. Watch for any bubbling or color change.
  6.  Carefully place a thermometer in the cup and record the temperature.

If we have time, we’ll also look at iron (III) chloride as a catalyst for hydrogen peroxide, and a reaction between zinc and sulfuric acid.

_________________________

Conclusions:

Once you have completed the lab, sit down and write a sentence or two to explain the results.

Discussion:

Record any thoughts you have about the experiments, including:

  • Possible improvements to the procedures or how to tweak techniques
  • How the results differed from your expectations
  • Suggestions for other experiments
  • What key concepts you learned about catalysts

Please leave a comment or send an e-mail if you have any questions before our meeting.

 

Lesson 19: More About Rates of Chemical Reactions

Last week was an introduction to rates of chemical reactions. This week we finish the chapter with Le Châtelier’s principle and speeding up reactions using catalysts.

Textbook Reading: Finish Chapter 15, pp. 546-566.

Le Châtelier’s principle helps predict the effect of disturbances to equilibrium in reversible reactions.

So, how do you pronounce Le Châtelier? Mr. Anderson at Bozeman Science has the answer:

The activation energy is the amount of energy that must be added to a system for two substances to react to form products. Some reactions don’t need much energy to proceed, like our sodium bicarbonate and acetic acid reaction last week. Others, like mixing hydrogen and oxygen gas to form water, take a lot of energy for the product to be formed.

activation-energy

In our lab we are going to take a look at how adding a catalyst can allow reactions to go forward with less added energy. The catalyst is not part of the reaction, that is it doesn’t end up in the product, but does allow reactions to happen that might not otherwise occur. Thus, catalysts can speed up reactions.

Please let me know if you have any questions.

Lab 18: Chemical Kinetics

For our lab this week we are going to look at some of the different ways to speed up reactions, as discussed in Lesson 18. We will be using our old friends sodium bicarbonate (baking soda) and vinegar, but this time we will quantify the rates of reactions. If we have time, we will see how changing the identity of one of the reactants changes the rate, as well.

Please read The Home Scientist pp. 106-113. We will be doing Session VI-1, pp. 108-113.

Experimental Title: Lab 18:  Determining the Effect of Temperature, Concentration, and Surface Area on Reaction Rates

Date of laboratory:  September 30, 2014

Purpose: The purpose of this lab is to determine the effect of temperature, concentration and surface area on reaction rates of acetic acid and sodium bicarbonate.

Introduction:

Please read the introduction to this topic on pp. 106-107 and the background on pp. 108-109.

The equation for the reaction is:

NaHCO3 + CH3COOH → CH3COONa + CO2 + H2O

To make sure the reaction runs to completion, we want a large excess of acetic acid so we’ll use 25 mL for each test run.

Special safety concerns for Lab 18:

  • If anything spills, please clean it up immediately with a paper towel and let your instructor know.
  • If glass breaks, do not pick it up with your bare hands. Notify your instructor immediately.
  • Be sure to wash your hands when you are finished with this lab

Materials:

See page 108.

Procedures: We will do parts I, II, and III on pp. 109-112. Please write the procedures in your notebooks.

Conclusions:

Once you have completed the three parts, sit down and write a sentence or two to explain the results of each part.

Discussion:

Record any thoughts you have about the experiments, including:

  • Possible improvements to the procedures or how to tweak techniques
  • How the results differed from your expectations
  • Suggestions for other experiments
  • What key concepts you learned about rates of reactions

Please leave a comment or send an e-mail if you have any questions before our meeting.

 

Lesson 18: Rates of Chemical Reactions

Reactions are where it is at in chemistry.

Textbook Reading:  First part of Chapter 15, sections 15.1-15.6, pp. 531-top of 546.

What controls the rate of chemical reactions?

According to the collision theory, when more atoms and molecules in a system are undergoing collisions, there is a higher chance they will bump together in such a way that a reaction can occur. For a reaction to occur particles must collide with enough energy and in the correct orientation. Even if correctly oriented, not all collisions successfully produce products because not all particles have minimum energy needed for the reaction to occur, or activation energy.

Hank Green of Crash Course Chemistry has a concrete way of explaining collision theory, activation energy, and reaction rate: demolition derby!

Another useful (but not too serious) analogy for increasing the rate of reaction can be found in this TED video: How to speed up chemical reactions (and get a date) by Aaron Sams.

So in summary, to speed up chemical reactions you need to:

1. Shove the reactants together by increasing the pressure.
2. Increase the concentration of the reactants or number of particles.
3. Heat the mixture to increase the energy level and number of collisions.
4. Increase the surface area of the reactants.
5. Add a catalyst to lower the activation energy level to what is available in the system.

We’ll be trying some of these methods in lab.

 

Edit: I’m adding this video from Mr. Anderson at Bozeman Science, too. He talks about the equilibrium constants.

Please let me know if you have any questions.