Transcript Lab 11: Neutralizing Power of Antacids

Due Today:
1 . Neutralizing
Power of
Antacids PreLab
NEUTRALIZING POWER
OF ANTACIDS
2. Acid-Base
Short Lab Report
Homework:
1. Neutralizing
Power of
Antacids Formal
Lab Report
2. Iron Content
Analysis Pre-Lab
OBJECTIVE
Measure neutralizing capacity of a
commercial antacid
Determine which brand is most cost
effective
PROCEDURE NOTES
Part I: Standardizing NaOH
 Completed in Acid-Base Titration Lab
PROCEDURE NOTES
Part II: Titration with simulated Stomach
Acid
Use GRADUATED pipettes
Add bromophenol blue indicator
 Yellow → Blue
 Make sure there is no green tint!
PROCEDURE NOTES
Part III: Stomach acid/Antacid Reaction
Record all pertinent information from packaging
Use GRADUATED pipets
GENTLY heat
 Heat no higher than 3
 Some solids may remain
Keep track of the # of pipets added
PROCEDURE NOTES
Part IV: Neutralizing excess Stomach Acid
Use GRADUATED pipets
Add bromophenol blue indicator
 Yellow → Blue
 Make sure there is no green tint!
WASTE
Titrated solutions → dispose in the sink
Excess NaOH → place in large carboy
RISK ASSESSMENT
Hydrochloric Acid
 Danger
 Inhalation Hazard
 Corrosive
Sodium Hydroxide
 Danger
 Inhalation Hazard
 Corrosive
CALCULATIONS
Total Moles of HCl added to antacid:
moles=M x V
V= (total number of pipets used)
1 Pipet = 25.00 mL
CALCULATIONS
Moles neutralized per dose
m𝑜𝑙𝑒𝑠𝑛𝑒𝑢𝑡𝑟𝑎𝑙𝑖𝑧𝑒𝑑 # 𝑜𝑓 𝑡𝑒𝑎𝑠𝑝𝑜𝑜𝑛𝑠
𝑥
1 𝑡𝑒𝑎𝑠𝑝𝑜𝑜𝑛
𝑑𝑜𝑠𝑒
Dose of antacid per dollar
𝑑𝑜𝑠𝑒
= 𝑑𝑜𝑠𝑒/$
𝑐𝑜𝑠𝑡
CALCULATIONS
Moles HCl neutralized per dollar
𝑚𝑜𝑙𝑒𝑠 𝑑𝑜𝑠𝑒
𝑥
= 𝑚𝑜𝑙𝑒𝑠/$
𝑑𝑜𝑠𝑒
$
You must collect ALL groups moles/$
values
ANTACID INFORMATION
Antacid
Active Ingredients
Price
Quantity
Dose
Rolaids
$4.99
150 tablets
3 tablets
Tums
$5.79
150 tablets
3 tablets
Mylanta
$6.29
12 fluid ounces
3 teaspoons
Maalox
$5.89
12 fluid ounces
3 teaspoons
Milk of Magnesia
$6.49
12 fluid ounces
2 teaspoons
COST EFFECTIVENESS COMPARISON
Antacid
Rolaids
Tums
Mylanta
Maalox
Milk of Magnesia
average experimental
neutralizing capacity
per dollar
theoretical moles HCl
neutralized per dose
theoretical neutralizing
Capacity per Dollar
percent difference