Conclusion …………………………………………………………………. 9
Bibliography ……………………………………………………………….. 9
Aim:
To use titration technique to test the ability or effect of two indigestion tablets (Rennie and Novagel) to neutralize the acidity of the stomach or lower the pH.
Hypothesis:
According to my literature review, since Novagel contains a mixture of Aluminium and Magnesium Hydroxide it will probably reduce the pH of the hydrochloric acid added to it more than Rennie. Since Rennie contains a mixture of Calcium and Magnesium Carbonate and according to my literature review again, those two compounds will help secrete more acid in the stomach which is not effective since its goal is to reduce the amount of acid secreted.
Literature review:
Indigestion, also known as dyspepsia, is a vague feeling of discomfort and pain in the upper abdomen and chest, including a feeling of fullness and bloating, accompanied by belching and nausea. Digestion is caused by eating particular foods, drinking alcoholic or carbonated beverages, eating too fast or too much, eating fatty or spicy foods, drinking too much caffeine, or eating too much high-fiber foods. Symptoms have also been shown to be worsened by anxiety and depression.
To cancel out excessive and to treat antacids are used, they are medicines used to neutralize an acidic stomach and reduce the amount of hydrogen produced which is caused by excessive secretion of hydrochloric acid in the gastric juices. They contain compounds such as calcium carbonate, sodium bicarbonate, aluminium hydroxide, magnesium carbonate, or magnesium hydroxide.
Best antacids are antacids which contain mixtures of Mg and Al because they only increase the pH of the acid and do not activate acid secretion while an antacid that contains Ca and Na increase pH thus activates further secretion of the acid.
To understand how antacids work, it is important to know the meaning of an acid and a base. Acids are compounds that dissociate (ionize) in water to form hydrogen ions (H+), their pH levels range from 0 to 6.9, they taste sour, change the Color of acid-base indicators (e.g., . A base is a substance which neutralizes, or is neutralized by an . Bases are generally oxides, hydroxides, or compounds such as ammonia which dissolve in water to form hydroxide ions. Bases have a range from 17 to 14.Bases are also called alkalis.
How does an antacid work? When heart burn occurs and an antacid is taken, the carbonate molecules in the antacid reduce the amount of hydrogen present in the stomach juice, in other words it neutralizes the acid and reduces its pH.
To test if an antacid works effectively or not, a simple test is done in the lab. Macroscale titration with burette procedure is a test that can show how strong or how effective an indigestion tablet is. First, the brands of the indigestion tablets are grinded with a, each powder is put in a different flask and labeled. 100mL of Hydrochloric Acid is added to the first powder and stirred while heated over a burner for 1-2 minutes till gently boiled. Turning off the burner, the solution is filtered in another clean flask. Two drops of phenolphthalein is added. Using a burette the solution is titrated with NaOH till endpoint. Record the exact amount of NaOH that is added to the flask. The solution will change Color indicating that is has been neutralized. This procedure is repeated for each brand, the lower the amount of NaOH used to neutralize the solution the more effective the tablet was when it lowered the pH of the acid Hydrochloric Acid.
Apparatus:
- 50ml burette
- 25ml measuring cylinder
- 250ml conical flasks
- Funnel
- Stand and clamp
- Teat Pipette
- 2 different types of indigestion tablets
- Methyl orange indicator
- 50 ml of 2 mol/dm3 hydrochloric acid
- 50 ml of 2 mol/dm3 sodium hydroxide
Procedure:
- Measure 25 ml of hydrochloric acid and pour into a conical flask. Add 3 drops of methyl orange
- Place the burette above the flask using the clamp and the stand
- place the funnel on the burette and fill it with sodium hydroxide up to the zero mark
- Add the sodium hydroxide slowly while swirling. Stop when the indicator changes Color
- Record the volume of sodium hydroxide added
- Clean the conical flask and fill the burette with sodium hydroxide
- Measure 25 ml of hydrochloric acid and pour into the conical flask, add one tablet of the first brand (breaking the tablets or grinding them in order to increase surface area for the reaction to take place)
- When the reaction stops , repeat titration and record the volume of sodium hydroxide used
- Repeat the titration using one tablet of the second brand
Results:
Tablet: Rennie
Tablet: Nafajel
Change in Color:
Discussion:
As we can see from the graph and results in both tables, Rennie needed less Sodium Hydroxide to neutralize the acidity of its powder mixture with Hydrochloric Acid, while Novagel needed more. The difference between the two results, or the total average of the amount of Sodium Hydroxide needed was little. As Rennie used 18.33mol/dm3 and Novagel used 19.6mol/dm3, the difference is only 1.27mol/dm3 of Sodium Hydroxide. Both these results compared with the amount needed to neutralize Hydrochloric Acid alone are very good, as Hydrochloric acid needed 30.23mol/dm3 of Sodium Hydroxide. So both these tablets in my opinion are good to lower the acidity of the stomach. In the experiment we used Methyl Orange Indicator to check the if the acidity is neutralized, and we know that methyl orange indicator when added to an acid will have a color of pink/red and when a base is added the color changes to orange, so as we can see all experiments using Novagel, Rennie and hydrochloric acid changed color from red/pink to yellow/orange.
Conclusion:
From this experiment we concluded that Rennie was better than Novagel as Novagel used more Sodium Hydroxide than Rennie but the difference between the two amounts of Sodium Hydroxide used for those two antacids were not very high. This experiment also proved my hypothesis wrong where my hypothesis was based on my literature review, so in other words the sources I have brought the information from for my literature review might probably be wrong, as it said that antacids containing mixtures of Aluminium and Magnesium increase the pH of an acid while antacids containing Sodium and Calcium increase the pH but at the same time they activate further secretion of acids.
If I wanted to repeat this experiment, I should make sure that during breaking or grinding the tablets no powder or parts of the tablets are lost, also washing and drying the apparatus used properly during use as little water maybe left in them.
Bibliography:
