Science Buddies: "Ask an Expert"

I tested the speed of neutralization of four antacids by placing the lowest recommended dose of each in 50 mL of 0.15 M HCL. I thought that Rolaids would work the best of the four tested (Tums, Gaviscon, Up&UP, Rolaids) because it has 2 active ingredients, calcium carbonate and magnesium hydroxide. Not only was it not the fastest, it never (in 10 trials) raised the pH to above 1.4!? It just didn't seem to work at all. Is there a scientific reason for that?

Hi esrohaes,

That is an interesting project and I'm glad to hear the the experimentation went well. I'm not sure that I can provide a direct answer to you, but my suggestion would be to look at the amount of active ingredient in each of your test antacids to see how much is present. If it isn't raising the pH much, it's possible that the quantity isn't very high. You may not be able to find this on the label, but the manufacturer should have this information and it would be an excellent addition to your report.

Best of luck and hope this helps!

mkjacobsen

Thank you for responding! Rolaids has 550 mg of calcium carbonate and 110 mg of magnesium hydroxide in each tablet. TUMS only has 500 mg of calcium carbonate per tablet but worked really well. I contacted Rolaids, but they said they could not help answer why this would happen because how their product works is proprietary information. What do I write in my conclusion if a scientific explanation does not exist to explain my results?

Thank you!

You can only explain what you know, which is that you saw a difference, the product had a different formula and the manufacturer declined to comment on your results.

It is not especially surprising that they did not respond. The formulation is a trade secret, and also your test results are not something that makes their product look very effective. Corporations have a profit motive, and that means they will only be helpful if they see an advantage that will help them make money. This is a problem with corporate sponsored science - results often can not be shared and those that are shared tend to be picked for results that make the company look good.

If it was important to figure this out, you could try different formulas until you got something with results similar to Rolaids. Sometimes that is all you can do, and with product research you will sometimes only know results, not the reasons. If you want to understand chemistry, it is better to use pure ingredients. But your question revolved around products, so there is nothing wrong with your results. Just be honest, and include the company response in your results.