Stoichiometry
My goal for this lab is to calculate the number of moles of NaOH needed to neutralize each type of aspirin.
In this lab, I had two types of aspirin:
low dose (containing 81 mg of aspirin) and regular strength (containing 325mg of aspirin).
I calculated the amount of NaOH I needed in order to do the titration, proceeded with the titration and identified my error.
In this lab, I had two types of aspirin:
low dose (containing 81 mg of aspirin) and regular strength (containing 325mg of aspirin).
I calculated the amount of NaOH I needed in order to do the titration, proceeded with the titration and identified my error.
Titration
The Titration is a way to quantify the amount of reactant present in a reaction. This tecnique is used for testing medicines to make sure that the right concentration is going into the tablets which is essential to make sure they are safe.
At the beginning of my experiment, I calculated the number of moles of NaOH that I was supposed to use to neutralize each type of aspirin using both mole-to-mole and grams-to-mole methods. My results were 4.5mL for the low dose aspirin and 18.00mL for the regular strength aspirin. |
I then used titration to confirm my calculations:
I put some NaOH in the burette and underneat an Erlenmeyer flask with the aspirin (which I grinded before), 2 drops of phenolphthalein indicator and 25.0 mL of DI water.
I added NaOH in 1 mL increments while contstantly swirling and looking for color changes. I stopped titrating when the color was permanent (phenolphathalein indicator made it pink).
The actual volume of NaOH needed was 6.00mL for the low dose of aspirin and 14.90mL for the regular strength of aspirin. For the low dose aspirin I had to add some NaOH because the amount I calculated was not enough.
The percent errors (actual amount used divided by the predicted amount) were
133.3% for the low dose aspirin and 82.78% for the regular strength aspirin.
I put some NaOH in the burette and underneat an Erlenmeyer flask with the aspirin (which I grinded before), 2 drops of phenolphthalein indicator and 25.0 mL of DI water.
I added NaOH in 1 mL increments while contstantly swirling and looking for color changes. I stopped titrating when the color was permanent (phenolphathalein indicator made it pink).
The actual volume of NaOH needed was 6.00mL for the low dose of aspirin and 14.90mL for the regular strength of aspirin. For the low dose aspirin I had to add some NaOH because the amount I calculated was not enough.
The percent errors (actual amount used divided by the predicted amount) were
133.3% for the low dose aspirin and 82.78% for the regular strength aspirin.
The low dose aspirin is sold in bottles of 300 pills at a cost of $11.98 ($0.039/pill).
The regular strength one is sold in bottles of 200 pills at a cost of $9.47 ($0.047/pill).
Using the grams-to-mole method I estimated the grams effective of aspirin to be 10.81g for the low dose aspirin and 26.84g for the regular strength aspirin.
The cost effectiveness (grams effective divided by cost per pill) is $0.0037 for the low dose aspirin and $0.018 for the regular strength aspirin.
The regular strength one is sold in bottles of 200 pills at a cost of $9.47 ($0.047/pill).
Using the grams-to-mole method I estimated the grams effective of aspirin to be 10.81g for the low dose aspirin and 26.84g for the regular strength aspirin.
The cost effectiveness (grams effective divided by cost per pill) is $0.0037 for the low dose aspirin and $0.018 for the regular strength aspirin.
Present technology
Generally the doctor prescribes the dose of medicine that the pharmacist has to give to the patient.
The pharmacist compares the doctor's note with the recommendations of the drug manufacturer to make sure that they are reasonable and safe. Drugs dosages are generally based on weight, age and gender but other factors like the severity of the disease, interactions with other drugs and kidney functions may have to be considered. Personalizing the dosage of medications can improve the effectiveness and reduce side-effects. In the future it will be interesting to explore the relationship between drugs and DNA to optimize the drug plan for each individual. |