Introduction:

The main domain of this lab report is to introduce experimental procedures in chemistry while conceptualizing the extraction techniques, volumetric analysis and wet chemistry and introducing different equipment being used frequently in chemistry. This report therefore is based on results of experiment to identify the acid neutralizing capacity of antacid tablet and identify the number of moles of HCL neutralized by the antacid tablet and NaOH. The report also identified the number of tablets required to bring the HCL in the stomach to a more normal level and identify possible sources of error in this experiment.

Aim:

This experiment is aimed to identify the acid neutralizing capacity of antacid tablet and identify the real neutralizing power of tablet. The experiment was also aimed to identify the number of tablets required to neutralize the HCL in the stomach to more normal level. The acid neutralizing capacity of antacid tablet is examined by converting it into fine powder, adding HCL and add methyl orange indicator to note the change is color. NaOH to an accurately known volume was added and noted the color change at the end-point. The neutralizing capacity of antacid tablet is measured through back titration technique.
Results Presentation:

• Items Tablet 1 (Bisodol) Tablet 2 (Renee)
• Mass of tablet 3.6 3.84
• Mass of Crushed Tablet 1.28 1.19
• Concentration of HC (mol dm-3): 0.5 0.5
• Volume of HCl added to the flask (ml): 39.4 38.9
• Initial Volume 0.2 0.5
• Volume in the End 39.6 39.4
• Concentration of NaOH solution (mol dm-3) : 0.5 0.5
• Volume of NaOH added to the flask (ml): 16.2 12.8

Calculations:

The amount (number of moles) of acid neutralised by the antacid can be determined by the total number of moles of HCl added minus the number of moles that were neutralized by the NaOH. Calculations based on findings of experiments are summarized as under.
Moles of HCL Added (nHCL) = CHCL * VHCL in ml
1,000
Bisodol (Tablet 1) = 0.5 * (39.4 / 1,000) in ml
= 0.0197 ml
Renee (Tablet 2) = 0.5 * (38.9 / 1,000) in ml
= 0.01945 ml
Moles of NaOH required for Back-Titration (nNaOH) = CNaOH * VNaOH in ml
1,000
Bisodol (Tablet 1) = 0.5 * (16.2 / 1,000) in ml
= 0.0081 in ml
Renee (Tablet 2) = 0.5 * (12.8 / 1,000) in ml
= 0.0064 in ml
Moles of Acid Neutralized = nHCL – nNaOH
Bisodol (Tablet 1) = 0.0197 – 0.0081
= 0.0116 ml
Renee (Tablet 2) = 0.01945 – 0.0064
= 0.01305 ml

Calculate the number of moles of NaOH used (C=n/v)
Number of moles of NaOH (Bisodol) = Concentration in mol/dm * Volume in dm3
= 0.5 * 16.2 (1/1000)
= 0.5 * 0.0162
= 0.0081 moles of NaOH
Number of moles of NaOH (Renee) = Concentration in mol/dm * Volume in dm3
= 0.5 * 12.8 (1/1000)
= 0.5 * 0.0128
= 0.0064 moles of NaOH
Calculate the number of moles of excess HCL added before titration
Moles of HCL added before titration (Bisodol) = Concentration in mol/dm * Volume in dm3
= 0.5 * 39.4 (1/1000)
= 0.5 * 0.0394
= 0.0197 moles of HCL
Moles of HCL added before titration (Renee) = Concentration in mol/dm * Volume in dm3
= 0.5 * 38.9 (1/1000)
= 0.5 * 0.0389
= 0.0195 moles of HCL
Calculate the number of moles of HCl that was neutralised by the antacid
Moles neutralized by Antacid = Number of moles of excess acid (#2) – number of moles HCl neutralized by NaOH (#1)
Bisodol = 0.0197 – 0.0081
= 0.0116 moles
Renee = 0.0195 – 0.0064
= 0.0131 moles
Calculate the number of moles of HCl neutralised by 1 antacid tablet
Number of Moles neutralized by 1 antacid tablet are same calculated in required 3 above as 1 tablet was used and requirement 3 calculated the moles neutralized by antacid.
Therefore:
Number of moles of HCI neutralised by 1 Bisodol tablet = 0.0116 moles
Number of moles of HCI neutralised by 1 Renee tablet = 0.0131 moles
How many tablets of the antacid will be required to bring the concentration of HCl in the stomach to a more normal level?
HCl concentration in Hyper Acidic Stomach = 0.030M
Volume of Liquid in Stomach = 250 mL or
= 0.25 L
Number of Moles of HCl in hyper acidic stomach = Volume * HCl Concentration (molarity)
= 0.250 * 0.030
= 0.075 moles
Number of moles nuteralized by 1 Bisodol tab. = 0.0116
Number of tablets required = 0.075 / 0.0116
= 0.65 tablets
Number of moles nuteralized by 1 Renee tab. = 0.0131
Number of tablets required = 0.075 / 0.0131
= 0.57 tablets

(Note: The HCl concentration in a hyper acidic stomach is 0.030 M. The volume of liquid in the stomach is 250 mL)