Analysis of Stomach Antacid TabletFull description
This is a scientific paper I made in our chemistry laboratory...a result & further research about the experiment we had conducted in our first sem during Finals.
This experiment is to determine the neutralisation capacity of commercial antacid tablet. Firstly, dissolve the tablet in an excess amount of acid of known concentration. Some of the HCl wil…Full description
Lab Report – Comparing the strength of different antacids Carolina Menezes
Data collection and processing Observations: • Antacid 1- white powder. • Antacid 2 – white tablet, white powder when crushed. • NaOH – colourless, transparent solution. 0.1M used with antacid 1 and 1.0M used with antacid 2. • HCl - colourless, transparent solution. 0.1M used with antacid 1 and 1.0M used with antacid 2. • Fizzing and effervescence occurred when antacid was mixed HCl. • Indicator used: methyl red – colour change: bright pink to orange. Equipment
Error
Digital balance
±0.001g
25 cm³ pipette (personal error)
± 0.23cm³
50 cm³ burette
± 0.05cm³ x 2 (for initial and final volume readings)
Run Mass of conical flask (g) Mass of conical flask with antacid (g) Mass of antacid used (g) Volume of HCl (cm3) Volume of NaOH (cm3)
1
Antacid 1 2 3
Av.
1
Antacid 2 2 3
Av.
107.38 6
106.49 3
124.22 8
122.80 0
145.44 5
101.09 8
112.40 5
111.57 5
129.20 6
127.91 4
150.54 2
106.17 2
5.019
5.082
4.978
4.999
5.114
5.097
5.074
5.095
25.0
25.0
25.0
25.0
25.0
25.0
25.0
25.0
9.90
15.8
10.0
9.95
18.9
18.0
18.6
18.5
1
Lab Report – Comparing the strength of different antacids Carolina Menezes
Antacid 1 Calculations
Errors and uncertainties
Moles of NaOH used = concentration x volume
Burette error = ± 0.05cm³ x 2 (for initial and final volume readings)
0.100 x 9.95 = 0.995 moles
0.10/9.95 x 100 = 1.01%
Moles of HCl neutralized = 0.995 moles Volume of HCl neutralized = number of moles / concentration 0.995/0.100 = 9.95 cm³ Volume of HCl neutralized by antacid 1 = initial volume – volume neutralized by NaOH
Balance error = ±0.001 g 0.001/5.095 x 100 = 0.02% Total error = 0.54 + 0.92 + 0.02 = 1.48% 1.48/100 x 1.28 = 0.019 mol g-1 Moles neutralized per gram of antacid = 1.28 ±0.019 mol g-1
Conclusion and evaluation From the results obtained from the practical, it is possible to see that antacid 2 is stronger than antacid 2 as it neutralizes more moles per gram of antacid (approximately 4.3 times as much). This however, should not be used as the sole aspect for comparison of the two drugs in general, as there are other factors that affect its efficiency such as pain relievers to relive the pain caused by the acid. 3
Lab Report – Comparing the strength of different antacids Carolina Menezes Therefore it is not possible to state that antacid 2 is better than antacid 1 but it is possible to confirm that antacid 2 is more effective in neutralizing hydrochloric acid. To improve the practical and obtain more accurate and reliable results, the first measure to be taken could be to find out the uncertainty of the concentrations of the solutions provided as these could later be added to the total percentage error and taken into consideration. Also, when the conical flask was being weighed there were variations in the reading because students kept leaning on the bench. In order to reduce these variations it would be advisable to have students away from the bench until the readings stabilized, reducing random error and increasing precision. The major problem concerning this practical, however, was that when obtaining results for antacid 2 is was difficult to determine what color could be considered orange and therefore determine when the solution had been neutralized, increasing random errors. A suitable solution would be to use a pH probe connected to a data logger and have it inserted in the solution. It would be clear when the solution was neutralized as it the pH reading would be 7 or around 7. Finally, having more repeats would also be suitable to increase precision.
