The purpose of this experiment is to investigate and compare the basic content of two antacids and also compare the prices and thus decide which antacid is more cost effective. This experiment is not hugely significant to the wider scientific community however it can help an uninformed consumer purchase a more cost effective antacid and understand how antacids work. The method used in this experiment is called a back titration. This involves adding HCl to an antacid tablet until an excess of HCl is reached and then titrating that solution against a 0.1mol NaOH solution. This will thus give us the number of moles each antacid neutralises. The average number of moles per gram neutralized by the Rennie tablets was 7.8409x10-3 moles. The average number of moles per gram neutralized by the Mylanta tablets was 6.3122x10-3 moles. It is obvious that Rennie antacids can neutralize more acid than Mylanta antacids. The Rennie antacids are also more cost effective as it costs less per tablet, they are more effective at neutralizing acid and therefore require a smaller dosage and also have no side effects unlike the Mylanta antacids which can cause diarrhoea.
There are several antacids on the market and many claim to be fast working and provide long lasting relief. An antacid is a substance that has a basic content that reduces the pH of gastric juice in the stomach. pH is a measure of the hydrogen ions in one litre of a solution which indicates the acidity (and basicity) of a solution. The scale used to measure the pH ranges from 0 – 14, 0 being very acidic 7 being neutral and 14 being very basic.
The pH of stomach acid ranges from 1 to 2 on the pH scale. The stomach constantly produces hydrochloric acid (HCl) as you eat. Therefore overeating, stress or other factors can cause your stomach to produce too much HCl this results in the usual pH level of your stomach decreasing from 1.5 to less than 0. This can result in severe pain for the individual at which point they will choose to take an antacid to relieve that pain. The Antacid reacts with the hydrochloric acid neutralizing some of the hydrogen ions causing the pH level to increase to the normal level. Taking too many antacids can cause the pH level to rise above 2 which will result in the stomach producing even more HCl which would only exacerbate the pain.
An example of this is Sodium Bicarbonate reacting with the HCl acid in your stomach:
NaHCO3 + HCl NaCl + H2O +CO2
Common bases used in antacids are Magnesium Carbonate, Magnesium Hydroxide, Aluminium Hydroxide, Calcium Carbonate and Sodium Bicarbonate. An antacid should decrease stomach acidity rapidly, maintain normal acidity in the stomach, yet not decrease acidity too much and have no side effects. Aluminium Hydroxide does a good job of meeting these requirements however it may cause constipation.
The two antacids being investigated in this experiment are Rennie antacids and...