Moles of CaCO3 = mass/RFM = 0.522/100 = 0.00522 moles
Moles of MgCO3 = mass/RFM = 0.068/84 = 0.000809538095… moles (13dp)
Moles of NaHCO3 = mass/RFM = 0.064/84 = 0.0007619047619 moles (12dp)
Equation for CaCO3 = CaCO3 + 2HCl >> CaCl2 + CO2 + H2O
Moles of HCl that should be neutralised = 2 x moles of active ingredient = 2 x 0.00522 = 0.01044 moles
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.01044/1 =
0.01044dm3 = 10.44cm3
Equation for MgCO3 = MgCO3 + 2HCl >> MgCl2 + CO2 + H2O
Moles of HCl that should be neutralised = 2 x moles of active ingredient = 2 x 0.000809538095 = 0.001523809524 moles (12dp)
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.001523809524/1 =
0.001619047619dm3 = 1.619047619cm3 (9dp)
Equation for NaHCO3 = NaHCO3 + 2HCl >> NaCl2 + CO2 + H2O + H
Moles of HCl that should be neutralised = 2 x moles of active ingredient = 2 x 0.0007619047619 = 0.00152380954 moles (11dp)
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.00152380954/1 =
0.00152380954dm3 = 1.52380954cm3 (8dp)
Total predicted volume of HCl needed = 1.52380954 + 1.619047619 + 10.44 = 13.5885716 cm3
Tablet = Boots Original
Active Ingredient = 0.2g CaCO3, & 0.06g MgCO3, & 0.06g NaHCO3
Relative formula mass = 100, & 84, & 84
Moles of CaCO3 = mass/RFM = 0.2/100 = 0.002 moles
Moles of MgCO3 = mass/RFM = 0.06/84 = 0.0007142857143 moles
Moles of NaHCO3 = mass/RFM = 0.06/84 = 0.0007142857143 moles
Equation for CaCo3 = CaCO3 + 2HCl >> CaCl2 + CO2 + H2O
Moles of HCl that should be neutralized = 2 x moles of active ingredient = 2 x 0.002 = 0.004 moles
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.004/1 = 0.004dm3 = 4cm3
Equation for MgCo3 = MgCO3 + 2HCl >> MgCl2 + CO2 + H2O
Moles of HCl that should be neutralized = 2 x moles of active ingredient = 2 x 0.0007142857143 = 0.001428571429 moles
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.001428571429/1 = 0.001428571429dm3 = 1.428571429cm3
Equation for MgCo3 = NaHCO3 + 2HCl >> NaCl2 + CO2 + H2O + H
Moles of HCl that should be neutralized = 2 x moles of active ingredient = 2 x 0.0007142857143 = 0.001428571429 moles
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.001428571429/1 = 0.001428571429dm3 = 1.428571429cm3
Total predicted volume of HCl needed = 4 + 1.428571429 + 1.428571429 = 6.857142857cm3
Tablet = Settlers
Active Ingredient = 0.5g CaCO3
Relative formula mass (RFM) = 100
Moles of active ingredient = mass / RFM = 0.5 / 100 = 0.005 moles
Equation = CaCO3 + 2HCl >> CaCl2 + CO2 + H2O
Moles of HCl that should be neutralised = 2 x moles of CaCo3 = 2 x 0.005 = 0.01
Concentration of HCl to be used = 1M (1mole per dm3)
Predicted volume of HCl needed = moles/concentration = 0.01/1 = 0.01dm3 = 10cm3
Active Ingredients
Super drug- 500mg CaCO3
Rennie- 680mg CaCO3, 80mg MgCO3
Bisdol-522mg CaCO3, 68mg MgCO3, 64mg NaHCO3
Boots Original-200mg CaCO3, 60mg MgCO3, 60NaHCO3
Settlers- 500mg CaCO3
Initial Plan
The initial plan is to find out which indicator shows the best colour change when the reaction occurs and what concentration of hydrochloric acid gives the best results. I will crush the antacid tablet and add water to it. I will then add Indicators to find out which is the best one that shows the colour change. I will then add hydrochloric acid bit by bit and then shake the conical flask to speed up the process. So you can find out the exact amount of acid that was neutralized.
Safety
- Wear goggles when handling corrosive solutions etc.
- Wear gloves
- Take of blazers & wear aprons
- Tuck in ties
- Report any breakages or spills
Fair test
To make it a fair test I will:
- Use the same amount of water each time.
- Use the same amount of bromophenol blue each time. By using too much you increase the volume even by the slight mm therefore decreasing its accuracy.
- Use the same volumes of acid each time from the burette.
- Either uses a whole tablet or a crushed tabled. By using crushed you allow more surface area therefore more reactions.
- It is essential that none of the powder be spilt or wasted as this may have major effects on the amount of hydrochloric acid to be neutralised.
Preliminary
To find if initial plan works and which indicator shows best color change and what concentration of hydrochloric acid gives best results.
The results above are Hydrochloric acid with a concentration of 0.5 Mole. Using 25cm3 of water and the color indicator bromophenol blue.
The results above are Hydrochloric acid with the concentration of 1 Mole. Using 25cm3 of water and the colour indicator bromophenol blue.
After conducting my preliminary experiments I have decided to continue using strength one mole hydrochloric acid and not strength 0.5. I have also decided that the amount of water used to dissolve the powder into is irrelevant as it makes no difference to the actual outcome but I will use 25cm3 of water. This would reflect the amount of water a person would intake with an indigestion tablet. Two test of each type of antacid is sufficient.
Conclusion
I notice from the results that with a 1 mole concentrated Hydrochloric acid the antacid tablet can neutralize more acid than the 0.5 mole concentrated Hydrochloric acid. I also acknowledged that the initial plan had worked and the method was correct. I also came to the conclusion that the Bromophenol Blue indicator is the best to use because it is a colour that is more distinct than the others when in this experiment.
Equipment
Clamp
Clamp stand
Funnel
Distilled water 25ml (for each test)
Measuring Cylinder
2 Conical flasks
Buirette
Bromophenol blue 10drops (for each test)
Mortar
Adapted plan
Firstly set up the equipment as shown in the diagram.
- Pour the hydrochloric acid into the buirette using the funnel. Up to 0dm³. If the acid has gone over the top either pour the excess acid into another flask or use the measurement in the table. A buirette shall be set up with a stand and lowered below eye height. This is important so that when adding acid none will spill causing possible eye damage.
- Crush the antacid tablet in a basin (to allow more surface area in the experiment).
- Put the crushed tablet into a flask.
- Pout 25mls of distilled water using a cylinder into the flask including the crushed antacid tablet.
- Add 10 drops of bromophenol blue to the solution.
-
Stir and place under the buirette. The conical flask shall be placed upon a white tile so and slight changes in indicator colour can be seen.
- Release the buirette clog and pour in 2dm³ of hydrochloric acid.
- Stir the solution until it reaches its original coulor.
- Keep performing this until u reach to 10dm³
- Then only release 1dm³ at a time and stir.
- When the indicator returns to its alkaline colour more acid should gradually be added, until alkalinity is not regained.
- The solution is then neutralized.
Results
Rennie tablet
Boots original tablet
Indigestion relief tablet
Superdrug
Settlers
Biodol
Analysis
Average Results
Analysis
Volume of moles in acid that was neutralised
-
Rennie Tablet Moles = dm3 × Concentration Moles = (15.5 / 1000) × 1 Moles = 0.0155 × 1 Moles = 0.0155
-
Indigestion Relief Tablet Moles = dm3 × Concentration Moles = (9.95 / 1000) × 1 Moles = 0.00995 × 1 Moles = 0.00995
-
Boots Original Tablet Moles = dm3 × Concentration Moles = (5.95 / 1000) × 1 Moles = 0.00595 × 1 Moles = 0.00595
-
Superdrug Tablet Moles = dm3 × Concentration Moles = (9.45 / 1000) × 1 Moles = 0.00945 × 1 Moles = 0.000945
-
Settlers Tablet Moles = dm3 × Concentration Moles = (9.95 / 1000) × 1 Moles = 0.00995 × 1 Moles = 0.00995
-
Biodol tablet Moles = dm3 × Concentration Moles = (12.05 / 1000) × 1 Moles = 0.01205 × 1 Moles = 0.01205
Looking at the results I found out that the most efficient and best tablet is the Rennie Tablet. This is due to it being able to neutralize the most acid. Not surprisingly in my prediction I predicted that this tablet would neutralize 32ml of acid but obviously the experiment was inaccurate as the antacid Rennie tablet was only able to neutralize half of the value predicted. Most tablets that I tested including my own came out as only able to neutralize this was either to my inaccurate testing or the incapability of the antacid to naturalize. The Boots original tablet did come close to my predicted measurement. Again this was promptly due to by inaccuracy and methods I used to test the antacids.
So when our stomachs produce gastric gas to aid indigestion and causes problems such stated in my theory The Boots original would be the ideal antacid to use to cure us of the disorder.
Evaluation
By analysing by results the experiment was successful to its aim and provided enough information for further investigation. But to make my data more accurate I could have done a number of things differently.
This experiment is not very reliable and accurate because you cannot find out the exact amount of acid the antacid can neutralize.
- Used a stirring machine to accurately stir each solution until it was fully neutralized.
- Some of the tablet was stuck to the basin so I could prevent it by using a different basin which wont let any crushed tablet to stay behind. This will allow my experiment to be more accurate because it is decreasing the volume of the tablet and alternating the calculations.
- Used less bromophenol blue as is again alternates the calculation as it increases the solutions volume. The experiment could have faulted due to the amount of indicator in the solution, which can affect it.
The Evaporation of the water from the solution in high levels of heat. If the acid was not added soon enough, the solution would become a suspension, and not all of the antacid will be put to use.
- If I were to repeat this experiment I would carry out each tablet between 3 and 5 tests and use a greater range of tablets.
Conclusion
I conclude The Rennie indigestion tablet was tested to be the best. This was because it was able to neutralize most volume in dm³ of hydrochloric acid. I believe to be due to its greater mass over the other tablets. It would have contained a greater amount of alkaline so could neutralise more acid.