What to do about CO 2 ? Steps, Content & Hints Main directions and content for the activity are in...

What to do about CO2?

Steps, Content & Hints

Main directions and content for the activity are in the boxes to the left with the orange border, like this one.

In a classroom setting, you will lead the students through the activity with a series of questions, the students’ own responses and brief explanations.

Whenever possible, find and affirm what’s right about the students’ answers.

Questions in Context:Do you remember something better when you are asked to think about it?

On the right, in the conversation bubble outlined in yellow, are guiding questions that you should ask the students during the associated step.

Each question should be asked separately – and a short amount of time should be allowed for responses.

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Set the Scene: Connect the Dots & Introduce the Activity Topic

Connect the dots for them: they are the future scientists who will help to discover and invent the solutions to the environmental challenges.

We will be learning about carbon dioxide today and the effect on the environment.

Has anyone ever seen dry ice before? What’s happening here? Sublimation is when a substance goes directly from a solid to a gas.

Who knows what we/humans breathe out? Carbon dioxide is part of the natural world and must be a good thing right?

Let’s do a few experiment and find out more about carbon dioxide.

Green Chemistry Introduction: Defining Green Chemistry

Have students work in pairs for 30 seconds to come up with a definition for green chemistry. Break down the meaning of both words.

Establish that Chemistry is the science of making products.

Eco-friendly, good for the environment, sustainable.

What do Chemists do?

Use wait time . Build off of their prior knowledge. Acknowledge student responses and prompt them for more information. Control the conversation by asking for a certain number of answers.

Chemists are inventors. They help to design just about every product out there.

Traditionally chemists were not taught about the environmental impact or toxicology. We have had many advances and helpful inventions but we have also had inventions that have caused harm to the environment. Green chemists design products taking into account the entire process, energy efficiency, renewable resources, the product itself along with the end-of-life impact of the product.

What is Chemistry? What does chemistry mean to you? Do you think of good things or bad things? Who has heard of companies going green? What does that mean?

Is there anything in this room that a chemist invented? What about the desks, paint, floor, etc.

Who has taken medicine? Does anyone use an iPod or an mp3 player? What about a computer or a cell phone?

Chemists make “stuff,” like materials and medicines. Green chemistry is pollution prevention at the molecular level, the basic design stage. So what is it that green chemists do?


Place 2 empty beakers in front of the class. Place concrete slabs at the bottom of each beaker. Crush one cube of dry ice and place in one beaker.Seal the top with parafilm.Seal the control beaker with parafilm as well.Ask students to make predictions/hypothesis.Come back to the beakers at the end of class and observe the changes.

*** Come back to this experiment at the end of the activities (or right after the ice cream is ready).

Discuss how there was a recent Presidential Green Chemistry Challenge Award winning technology that is making products using CO2. Also many researchers trying to develop CO2 absorbent concrete.

Green chemistry technology considers 3 criteria:Safety, Cost and Performance

Let’s understand a little bit about the problem and see if we can use green chemistry technology to create a solution.

What do we think is going to happen in this experiment? We know that CO2 is absorbed by plants will the CO2 be absorbed by the concrete? Why or why not?

Let’s come back to this at the end of our session.


pH is a measure of acidity or basicity of a solution. Whether a liquid is an acid or a base depends on the types of ions in it. If it has a lot of hydrogen ions it’s an acid. If it has a lot of hydroxide ions then it is a base.

We are going to start by playing a game to talk about pH. Each group will get a table with the 1-14 scale. You will see a few of the common products are in place whether they are acidic (1) or basic (14).

We are going to break the class into groups of 4 students. Each group will receive a set of images to match on the pH scale table. Do your best to fit the corresponding images with the pH numbers.

Each group will share out one of their matched images and pH estimate.

Take a look at the pH of sea water. Today we are working with CO2 . Ocean acidification is a problem related to excess CO2 in the environment. When one part of the ocean is more acidic that means all of the ocean is more acidic. Locally and globally ocean ecosystems are affected that means both coral reefs in Australia and lobsters in Boston!

What is the pH of distilled water?

It’s ok not to know the answers this going to help us to talk about the differences between acids and bases.

Do we know anything about CO2 problems or challenges? CO2 is a greenhouse gas contributing to global climate change it is also causing ocean. Where is this excess CO2 coming from? The burning of fossil fuels produces excess CO2. Why do we need to burn fossil fuels? Energy etc.

Has anyone ever spilled orange juice on a cut

before? Did it sting? Does OJ have more hydrogen ions or hydroxide ions?

Acids and bases neutralize each other. Did you know

that our stomachs use hydrochloric acid to help

digest food? Good thing we have a protective liner.


Add 5 drops of indicatorUsing a protective glove, place 2 pieces of dry ice in a wash bottle with some warm water. (When you close the wash bottle you should have a steady stream of CO2

coming from the spout.)Insert the wash bottle spout into the container with the salt water solutionObserve and report what happensAdd base & repeat if time permits

What did happen? Is CO2 an acid or a base?

How can we limit the amount of excess CO2 in our environment?

What if our concrete acted as a CO2 sink?


Procedure:Measure 50 mL of salt water solution using graduated cylinderPour salt water into 150 ml beakerTest the pH of the sea water with pH strip

Take a look at the pH of sea water. Today we are working with CO2. Ocean acidification is a problem related to excess CO2 in the environment. When one part of the ocean is more acidic that means all of the ocean is more acidic. Locally and globally ocean ecosystems are affected that means both coral reefs in Australia and lobsters in Boston!

What is the pH of the sea water? What do you expect will happen when we spray CO2 gas into the sea water?

Ocean acidification is one of the problems connected to excess CO2 . We are going to do an experiment today that simulates those conditions.

Let’s use CO2 to make ice cream!Hand out the materials. Each student gets 2 bags, ½ cup of whole milk, 1 tbsp of sugar and ½ tsp of vanilla

Demonstrate putting one bag into the other.Once students have baggies they add:½ cup of whole milk1 tbsp of sugar½ tsp of vanilla(Depending on the time and size of the group you may want to pre-measure ingredients) Other wise you can prepare bowls of the supplies for each table and allow students to measure themselves.

Once ingredients have been mixed together remove as much air as possible and seal the Ziplock bags tightly. For added security tape the outside bag closed.

What do we need to make ice cream?

Has anyone every made it before?

Create a dry ice bath using salt, water and dry ice (REMINDER: Dry ice is much colder than traditional ice at -109.3°F or -78.5°C don’t let students handle with bare hands) Each dry ice bath will have 2-3 L of water and ½ a container of salt and 500g of dry ice If the mixture is not slushy enough adjust by adding more water, dry ice and/or saltInstruct the students to agitate their mixture in the bags while submerged in the dry ice mixture

green chemistry technology has 3 criteria:

cost, safety & performance

Let’s test the performance of our ice cream.

Making the ice cream will take anywhere from 10-15 minutes depending on the dry ice slurry.

After we eat our ice cream let’s re-cap


Let’s look back at the beakers from the start of this activity.

Presidential Green Chemistry Challenge Award Winner2012 Academic Award Professor Geoffrey W. Coates, Cornell University

Carbon dioxide and carbon monoxide are ideal feedstocks for chemicals but until now there had been no efficient way to make them into valuable polymers. Professor Coates created a family of catalysts that convert CO2 and CO into polymers. Novomer is the company that is using the technology to make a wide range of products.

There have been several companies over the past few years who have made headlines for researching and developing concrete that absorbs moreCO2 than it takes to make it. Currently 5% of all CO2 greenhouse gases can be traced back to the manufacturing of concrete.CO2 sinks and capturing CO2 is a big area of research. You could be the one to help solve the problem!

What happened to the beakers? Did we see a

change?

What if we could capture CO2 and convert it into

useful materials?


In Closing:

Green chemistry provides the tools needed for creating solutions to environmental challenges.

As a green chemist you can be a part of the solution by inventing better technologies for the future. Also remember that you do not need to be a scientist to make a difference in this world. As an informed citizen you have the power to influence change with your decision making, voting power and purchasing choices.

Any questions?Wrapping up is always a good time to talk a little more about why you are in the classroom, what you are studying, researching or pursuing as a career.

Reiterate the 3 criteria of safety, cost and performance.

Great Job! Scientists ask questions and seek out answers.

Reinforce how green chemistry is the science of solutions!

Who here asks questions about how products are made or why we have certain problems?Sounds like we have some green chemists in the room. Who thought that this was easy? Who had fun doing this? Do you think that science is something that you can do?


What to do about CO 2 ? Steps, Content & Hints Main directions and content for the activity are in...

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