STEM Outreach with BASF: Exploring Chemistry - Clean Water and pH

It has been a busy summer, but I finally got back into a classroom to have fun doing science with middle schoolers.  It has only been a few weeks since I transitioned from Bayer to my new employer BASF as part of a large divestement.   Yet in that small amount of time, it did not take long at all to see that BASF is also a strong agvocate in our community.   As a large BASF group we all took half a day to head over to East Wake Middle School in North Carolina to meet a bunch of 8th graders.

Game faces were on as a bunch of enthusiastic folks from BASF wore their green shirts with pride.

Some of have been doing outreach together for a long time so you gotta take advantage of selfie moments.

Once we loaded up it was a short trip to East Wake to meet the students.  We split up into groups and headed to our classes where my team ended up meeting Ms. Shores class.   What a great opportunity it was to take some time out of our busy day and work with students and to work closely with my BASF colleagues Courtney, Paulette, Casey, and Yasmin.  This is an account of my expereince with one class, but there were similar stories going on across many other classroms with other teams.

We first had to safety up.  And we would not look like scientists without our lab coat, glasses, and gloves!

Our first experiment was on pH.   We used red cabbage juice as a pH indicator which I have shown before in a previous post.  If you are interested in more details on pH experiments here is the link:  https://atransgenicworld.blogspot.com/2017/02/science-for-kids-ph-fun.html

The last time I used cabbage juice as a visual indicator of pH I just used some powder extract you can buy on amazon.    The organizers of our group went an extra mile and actually made the cabbage juice indicator the night before.   So if you want to make you own, here are the instructions.  Instructions are courtesy of BASF materials.

After explaining a little about pH we tired all kinds of stuff to see if it was acidic or basic.

Next up we talked about water and they all agreed clean water is super important.   We showed that water can have different types of contaminants.  Soil, sand, and dirt make water dirty, but so do other contaminants like  heavy metals or other chemicals.   We had a tube of water with sand and used food coloring to show other contaminants.   This dirty water definitely needed cleaning up.  First it went through just a regular filter and everyone's hypothesis that the filter would just catch the sand was correct.  The water no longer had dirt in it but it was still colored from the food coloring. 

First we added the water to just a paper filter.

The next thing we learned was that activated charcoal is a material that can help clean up water.  Everyone had their dirty water with dirt and food coloring to try and clean up again.  They put it through a paper filter again, but this time it also passed through some activated charcoal that we had added to the top of the filter.   I heard a few gasps when the water really did come out clear and clean as oppsed to dirty and red from the food coloring.

Lastly we just had a chance to talk.  Each of us from BASF joined 4-5 students and had about 10 minutes to just talk.  Of course the topic of video games did come up and most of them did indeed play Fortnite.  Maybe I gained a little more respect when they learned I like to play Fortnite too.   But I also heard such ambition and drive from this group.  One young lady wanted to be a Youtuber.  When I asked how many subscribers she had, she reported it was over 1000!!  I told her I barely get 5 likes on my instagram pictures!   They are so talented!  There were two that wanted to be marine biologists, 2 who wanted be a doctor, a couple that wanted to soccer players, one that wanted to be a lawyer, and other aspirations  And of course some who did not know which is OK too.   I did not even know what I was going to be and more importantly really like until I got my second job after college. 

Whatg a great day.   Thanks to the teachers, to the school, and to BASF for organizing this day.  I encourage all of you to pour your knowledge and passion on a subject into this generation whenever you get the chance.  They listen, they question and they fill you with hope for our future.

Chemistry Fun - How does the antacid Gaviscon work?

Have you ever had heartburn and gone to the medicine cabinet to grab some relief.   Then have you ever stopped and wondered how that medicine is actually working?   Heartburn  is caused when acid from the stomach moves up in the esophagus.  The sphincter muscle controls the opening from the esophagus to the stomach so if this muscle does seal correctly you can feel heartburn.  The stomach is covered in thick mucous and is protected from the acid, but the esophagus does not have that protection.

One way antacid can work is by reducing the acidity of the acid in your stomach.  If the acid is not as strong it will not inflame the esophagus as much.  However the antacid Gaviscon works a completely different way and the chemistry is pretty ingenious.

The main ingredients of Gaviscon are:

Sodium alginate
Sodium bicarbonate
Calcium carbonate.

The chemistry behind Gaviscon is pretty neat. 

Sodium Alginate is a polymer that is derived from seaweed.  Once it goes into the stomach, the acid in our stomach makes it go from a soluble state to an insoluble state.  In other words it becomes a solid.   Secondly there will be Calcium ions in the stomach from the calcium carbonate.   The calcium helps to cross-link the alginate molecules together into something called an "alginate raft."  You are left with a big piece of solid material in your stomach from the medicine.

The second piece of the story is the calcium carbonate and sodium bicarbonate react with the acid in your stomach to form carbon dioxide gas.   The gas that is formed propels the solid alginate raft upwards.  It gets caught at the top of the stomach where the esophagus and stomach come together and forms a barrier.  This barrier prevents acid from going up into the esophagus. 

This is an amazing piece of chemistry and all of it relies on the acid in our stomach to start the reactions.  The neat part is we can replicate the experiment. 


Supplies needed: 

• 250 ml flask:  This replicates your stomach.  The bottom portion is your stomach and the neck of the flask is your esophagus. 
• 50 mL Gaviscon liquid
• 150 mL of 1M Hydrochloric Acid - This can be pretty nasty and most will not have access to this.  So be very careful if you do. (safety glasses, coat, eye protection)

The Experiment

This experiment is quite simple.
1. Add 150 mL of 1M HCl into the flask
2.  Add 50 mL of Gaviscon to the flask
3.  Observe

Watch the Gaviscon go from a liquid to a solid while the alginate raft forms. Observe Carbon dioxide bubbles forming.  And finally watch the gas push the raft up to the neck of the flask and form a barrier.

The barrier actually makes it difficult to get the HCl out of the flask when we cleaned up!!

You just saw a real life application of chemistry in a over the counter medicine thousands of people use everyday.  And it was so fun seeing the students doing the experiment.