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This experiment was how Mylnata and Gaviscon worked against stomach acid....

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By Albert Binu

Effectiveness of Commercial Antacids: Gaviscon and Mylanta

Research Question: Which antacid (Gaviscon and Mylanta) is more effective when neutralising Hydrochloric Acid to a pH of 6 when the concentration and amount of acid is kept the same.

Hypothesis: The Gaviscon will be more effective at neutralising the acid because it absorbs more Hydrochloric Acid than Mylanta and also reacts with the HCL almost instantaneously. The sodium alginate reacts with the HCL which creates a gel that floats to the top of the stomach contents which stops the stomach acid from rising.

Background: In this investigation, Mylanta and Gaviscon were tested for their effectiveness in neutralising stomach acid. “Acids are a substance that separates in water to produce a hydrogen ion (H+). The strength of an acid is dependent on the solution’s H+ ion concentration. The greater the H+, the more concentrated the acid. Bases are a substance that separates in water to create a negatively charged hydroxide ion (OH-). The intensity of (OH-) determines the strength of the base (more hydroxide ions = further concentrated base).” (Lewis, 2020). A pH scale measures how acidic/alkaline a liquid is. It is a range of numbers from 0-14, whereas pH=7 being neutral, pH7 indicating acidity. A universal indicator is a mixture of solutions which changes colours depending on the pH number (A red colour is a pH from 0-2 which represents strong acidity, and a purple colour is a pH from 12-14 which means strong alkalinity). A neutralisation reaction is a chemical reaction which involves a combination of an acid (H+) and base (OH-) reacting with each other producing water and salt. The general word equation for the reactions of acids and carbonates are: Acid +Carbonate → Salt +Carbon Dioxide+Water . The word equation for the reaction of acid and bases are: Acid + Base→ Water + Salt . Neutralisation is an important treatment for indigestion because it lowers the pH level of the stomach acid and reduces the effects of excessive acid. Gaviscon: contains Sodium bicarbonate (NaHCO3), and Calcium carbonate (CaCO3). Mylanta: contains Magnesium hydroxide (Mg(OH) 2), Aluminium hydroxide (Al(OH)3). Balanced Equations for Gaviscon and Mylanta: NaHCO3+HCl+NaCl+CO2+H2O CaCo3+2HClCaCl2+CO2+H2O Al(OH)3+3HClAlCl3+3H2O Mg(OH)2+2HClMgCl2+2H2O Gaviscon is more effective than Mylanta because it reacts with stomach acid much quicker and

By Albert Binu

creates a protective layer that floats on top of the substances in the stomach. This stops stomach acid from reaching the oesophagus. The energy required for a chemical reaction to start is called activation energy. Energy changes can be measured in a chemical reaction by comprehending the changes of energy in the surroundings. Heat loss/gain in a chemical reaction = heat gained/lost by the surroundings, then the energy changes in chemical reaction can be determined. There are two types of chemical reactions: Endothermic and Exothermic. Endothermic absorbs heat from the surroundings in the form of heat, and exothermic releases heat into the surrounding. Neutralisation reactions are usually exothermic because they release heat until the reaction has been neutralised.

Materials and Equipment: Chemicals    

Newspaper (to avoid universal indicator stains on bench) Universal indicator solution in dropper bottle with laminated pH colour chart 0.1M hydrochloric acid (HCl) in dropper bottle 10% v/v solutions of liquid antacids: o Gaviscon (contains NaHCO3, CaCO3, sodium alginate [C 6H9NaO7]) o Mylanta (contains Al(OH)3, Mg(OH) 2, simethicone [C6H18O8Si3])

Equipment  marker pen  1 x 250mL beaker  2 x 10mL measuring cylinders  6 x test tubes  test tube rack 4 x plastic dropper pipettes

Original Procedure: In the original investigation, instead of using 0.1M HCl, 0.5M HCl was used and poured into a test tube (x3). Next 10mL of Sodium Hydrogen Carbonate was measured and added into the test tubes with pipette drops until neutral pH was reached (green colour) instead of 6 pH (yellow colour). Then these steps were repeated again for Sodium Carbonate.

Changes to the Methodology: In the latest experiment, 3 mL of the antacids Mylanta and Gaviscon were poured into test tubes instead of Sodium Hydrogen Carbonate and Sodium Carbonate. Also instead of having the base neutralise the acid , it was switched the other way round (HCl neutralises antacids). The concentration of the Hydrochloric Acid changed from 0.5M to 0.1M to replicate the intensity of

By Albert Binu

real stomach acid. However, the goal of both experiments stayed clear, to view which antacid is most effective at neutralising HCl.

Risk Assessment: Table 1 - Risks Analysis

Activity

Risk

Beakers and test tubes

Beakers or test tubes can slip off the table and can shatter on the floor which and impale the legs or hands. There could be chips or cracks on the glassware which can cause chemical spillage and cuts. Things such as glass can slip off the newspaper. It is flammable and can easily catch fire.

Newspaper

Universal indicator

0.1M Hydrochloric acid

If spilled on hands, it can cause moderate skin irritation. If the solution is absorbed through the skin, it may even cause indigestion problems. If spilled, it can damage eyes and cause skin irritation

Gaviscon (contains NaHCO3, CaCO3, sodium alginate [C6H9NaO7])

Consuming this product extensively can have an effect

Mylanta (contains Al(OH)3, Mg(OH)2, simethicone [C6H18O8Si3])

Consuming this product extensively can have side effects on body.

Results:

Controls and Treatment (PPE required, strategy for reducing risk, treatment) Keep glassware away from the edges of the table and check for any cracks or chips. The test tubes should be placed on a test tube rack, so it doesn’t roll off the table.

Avoid use near naked flames.

Wear protective gloves, protective clothing, and eye protection.

The HCl was diluted to 0.1M and safety goggles and rubber gloves should be worn until lab space is cleared. Also use a test stube holder and be cautious. Not brining the product close to the face and consuming only the recommended amount. Not brining the product close to the face and consuming only the recommended amount.

By Albert Binu

Table 2 - The Amount of Hydrochloric Acid an Antacid can Absorb, including observations

Antacid Gaviscon

Initial pH 8

Volume of hydrochloric acid required to neutralise acid (mL) Trial 1 Trial 2 Trial 3 Average 21 drops (0.9ml used) (9.1ml left)

18 drops (0.6mL used) (9.4mL left)

20 drops (0.8mL used) (9.2mL left)

20 drops

6 drops (0.2 mL used) (9.8mL left)

7 drops (0.3 mL used) (9.7mL left)

8 drops (0.3mL used) (9.7mL left)

7 drops (0.3mL used) (9.7 mL left)

(0.7 mL used) (9.3mL left)

Mylanta

8

Observations

Gaviscon –  Cloudy when poured into test tube  After universal indicator is added the colour turns blue-green (8pH – weak alkali).  When HCl was added it was much the solution turned yellow, was fast reacting, and had instant neutralisation (6pH – weak acid)  The reaction produced air bubbles  A gel layer formed and floated to the top of the Hydrochloric Acid.  When tipping out the gel out of the test tube, some of the precipitate was stuck to the bottom of the test tube and could not be removed. Mylanta –  Is cloudier than the Gaviscon liquid  After universal indicator was added the colour turns blue-green (8pH – weak alkali)  When HCl was added it was much the solution turned yellow, was fast reacting, and had instant neutralisation (6pH – weak acid)  The antacid separated into Aluminium Hydroxide and Magnesium Hydroxide  Mylanta was long lasting  Had a slow reaction and did not absorb much Hydrochloric Acid

Gaviscon absorbed more drops of Hydrochloric Acid to get neutralised to the pH point of 6. Discussion: The results shown above prove that Gaviscon is the best antacid which neutralises stomach acid by providing rapid acting relief in mild or high cases of heart burn. Gaviscon absorbed an average of 20 drops of Hydrochloric Acid whereas Mylanta absorbed 7 drops which means Gaviscon is the superior antacid. In the experiment, both antacids initially started with a pH of 8, then Hydrochloric Acid was added in drops to neutralise the base to a pH of 6 to see which antacid was more effective. Based on the results, antacids with calcium carbonate react much quicker, this why Gaviscon is the

By Albert Binu

Bibliography Advanced Institutional Systems Inc, 2011. Lab 4 - Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration. [Online] Available at: https://www.webassign.net/labsgraceperiod/ucscgencheml1/lab_4/manual.html [Accessed 23 November 2020]. Gillson, S., 2020. Using Gaviscon for Heartburn. [Online] Available at: https://www.verywellhealth.com/gaviscon-antacid-treatment-for-heartburn-1742170 [Accessed 23 November 2020]. Harshitha, S., 2020. Effectiveness of Antacids Author: Sri Harshitha Introduction. [Online] Available at: https://gradesfixer.com/free-essay-examples/effectiveness-of-antacids-author-sri-harshitha-

By Albert Binu introduction/ [Accessed 22 November 2020]. Landridge, T. & Ramsay, P., 2020. Chemical Rate of Reaction Formative Practical. [Online] Available at: https://www.thinkswap.com/au/sace/chemistry/year-11/chemical-rate-reaction-formativepractical [Accessed 22 November 2020]. Lewis, G., 2020. Overview of Acids and Bases. [Online] Available at: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplem ental_Modules_(Physical_and_Theoretical_Chemistry)/Acids_and_Bases/Acid/Overview_of_Acids_and_ Bases [Accessed 23 November 2020]....