INTRODUCTION pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at 25 °C (77 °F). Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline.
An antacid is a substance which neutralizes stomach acidity. Antacids perform a neutralization reaction, increasing the pH to reduce acidity in the stomach. When gastric hydrochloric acid reaches the nerves in the gastrointestinal mucosa, they signal pain to the central nervous system. This happens when these nerves are exposed.
Antacids are taken by mouth and work by neutralizing excess stomach acid. They contain ingredients such as aluminum hydroxide, calcium carbonate, magnesium hydroxide, and sodium bicarbonate, alone or in various combinations. Antacid products may also contain other ingredients such as simethicone, which relieves gas.
Antacids differ in how quickly they work and how long they provide relief. Those that dissolve rapidly in the stomach, such as magnesium hydroxide and sodium bicarbonate, bring the fastest relief. Antacids that contain calcium carbonate or aluminum dissolve more slowly and can take up to 30 minutes to begin working. The longer an antacid stays in the stomach, the longer it works. Those that contain calcium carbonate or aluminum work longer than those that contain sodium bicarbonate or magnesium. Also, taking any kind of antacid after a meal, instead of on an empty stomach, provides longer-lasting relief because the medicine stays in the stomach.
PROBLEM
What particular drug among Alka-seltzer, Rolaids and Tums is more effective when it comes to neutralizing acidity of the stomach?
HYPOTHESIS/PREDICTION
If a certain drug needs higher amount of drops in order for it to change its color, then that particular drug is a good buffer.
MATERIALS
Alka-Seltzer
Rolaids
Tums
0.1 M hydrochloric acid (HCl)
References: Vodopich, Darrel, and Randy Moore. Biology Laboratory Manual. 9thth ed. N.p.: The McGraw-Hill Companies, Inc, 2011. 60. Print. http://en.wikipedia.org/wiki/PH http://en.wikipedia.org/wiki/Antacid http://www.faqs.org/health/topics/50/Antacids.html