Today was the second day of the Marooned on Mars project and most groups began with the very first goal on their list: Obtaining safe drinking water. But this was no easy task. Because we were unable to create H₂O using a chemical reaction (Mr. A has learned his lesson about trying to burn hydrogen), we had to resort to trying to purify wastewater.

This was really a three step process. First, we had to lower the PH of the wastewater by adding an acid. Second, we had to filter out any poisons using charcoal. And third, depending on how we viewed the likelihood of germ contamination, we had to boil the water to sanitize it.

Remember everyone, at the end of the week you must hand in a lab procedure that includes a goal, a materials list, a procedure, a chemical reaction equation (if one was used), and a drawing of the reaction. The equation for the wastewater reaction, “citric acid + calcium carbonate,” can be found below.

December 2-4 – Marooned on Mars (pg318)

The capstone project for Unit 3 is called “Marooned on Mars,” and it’s based on the movie The Martian. In the film, astronaut Mark Watney is stranded alone on the planet, and the nearest help is 140 million miles away. The question we will be trying to answer is “What would Mark need to do to survive?” or more specifically “How could chemistry save him?”

Mark is alive and healthy in the solar-powered living quarters, and he is well protected from the elements. So his survival will mostly be a matter of resources. In order to survive until a rescue mission can reach him, there are four basic resources that Mark must obtain.

1. Water.
2. Oxygen.
3. Clean air.
4. Food.

Over the course of the week, students will play the role of NASA chemists, instructing Mark on how to solve each of the problems above. Unfortunately their materials are very limited. The mission was only supposed to last 31 days, so they will have to make do with whatever supplies Mark has access to: beakers, funnels, charcoal, PH strips, sodium carbonate, waste-water, matches, citric acid, limewater, etc.

At the end of the week, students will hand in a lab report that details their instructions. The report must contain materials lists, lab procedures, chemical reaction equations, pictures, and anything else that Mr. Watney might find useful. So work hard, everyone. Mark’s life is in your hands.

December 1 – Marooned on Mars Introduction (pg317)

Unit 3 is coming to an end. So today we took the opportunity to reflect on some of the chemical reactions we have seen so far. Students chose five of our CRotDs and practiced writing the reaction equations, drawing pictures, and classifying the reactions. Then they revisited them by watching the videos on www.MrAscience.com, and recalling which of the four clues they each displayed. Tonight’s HW is to finish the assignment (Page 316).

November 30 – CRotD Reflections (pg316)

Regular science classes were cancelled today due to the FBMS Turkey Trot. Normal classes will resume on Monday. Have a great Thanksgiving, everyone!

Today we continued our investigation of the Law of Conservation of Mass, but this time we used the classic “baking soda and vinegar” reaction. When baking soda mixes with vinegar, it causes a chemical reaction which produces sodium acetate, water, and carbon dioxide. The observable clues are that it bubbles and also turns cold.

Students carefully measured the mass of the baking soda and vinegar before and after the reaction. And, much tot heir surprise, the mass decreased. So were we breaking the law? We wondered. Students then repeated the experiment a second time, but this time they covered the reaction with a balloon.

By trapping the CO₂ that the reaction created, we were able to prove that mass was, in fact, conserved. The reason we saw a mass decrease during our first test was that the carbon dioxide escaped. When covered with a balloon, however, the masses before and after were about the same. No going to jail today either 😉

November 25 – LoCoM Lab – Baking Soda & Vinegar (pg315)

A few hundred years ago, things were different. In order to light a fire, you would have to get out your flint and your steel, strike them, and hope that the few sparks you made would light your kindling on fire. Today, you simply use a match. A few hundred years ago, they thought that fire would actually destroy the firewood and only the ashes would be left. Today we know better.

Fire cannot destroy matter. In fact, according to the Law of Conservation of Mass, formally discovered in the late 1700s, no matter can ever be created or destroyed. We can rearrange atoms, we can break their bonds, we can move them around, and we can release them into the air. But we cannot destroy them.

Today in class, students investigated this law. They measured the mass of a piece of paper, then crumpled that paper and weighed it again, then ripped up the paper and weighed it a third time. The mass of the paper never changed. Then they measured the mass of a match, burned it, and weighed it again. This time, the mass did change!

It turns out that the burning of wood generally follows the equation above (wood is a mixture, so it is hard to describe with one simple equation). Most of the wood that is burned turns into CO₂ and H₂O, and thus it escapes into the air. What is left behind are impurities, mostly charcoal and ash. Even though it seems as though burning wood breaks the law, it actually doesn’t. So rest easy everyone, you won’t go to jail today.

November 24 – LoCoM Lab – Lighting a Match (pg314)

After handing in our lab reports, we began today’s class with our latest CRotD: burning gasoline. While it surprised no one that burning gasoline was a chemical reaction, what students didn’t know was that the reaction mostly produces steam (H₂O) and carbon dioxide (CO₂). The expansion of those two gases is what powers your car’s engine.

After watching the gasoline reaction, we did a review carousel. Students moved from table to table answering chemistry questions and then checking their work. Students who were absent or wish to review the material can access the questions by clicking the link below.

November 20 – Review Carousel (pg313)