A physician has came across a shop of old aspirin tablets and wants to cognize if they have the right sum of the active ingredient so that he can utilize them, or donate them for usage by charity administrations.

Aspirin is an anti inflammatory drug that is besides used as a febrility reducing agent. If it frequently used for mild annoyance or hurting, giving speedy alleviation to caput achings, colds and grippe.

Using an acid/base titration is a straightforward manner of finding how much ethanoyl group salicylic acid they contain by adding a solution to neutralize the acid.

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2 hydroxybenzoic acid now called salicylic acid is a works

endocrine, which can besides be used in cosmetics as a preventer of acne.

Aspirin was foremost discovered in ancient Greece where willow tree infusions were made into a drink to handle labour strivings. The different strengths of aspirin depend on the sum of acetyl salicylic acid they have in them. It has besides been tested as it is thought that acetylsalicylic acid can diminish the opportunities of people acquiring bosom onslaught and shots etc this is because it reduces the production of the prostaglandin thromboxane which is involved in coagulating blood.

Nowadays we do n’t acquire aspirin from willow trees but do it unnaturally by the synthesis of acetylic acid. Aspirin has been synthesised from the reaction

Salicylic acid + acetic i? acetylsalicylic acid + acetic acid

Over clip, Aspirin can “ travel off ” by responding with wet in the air and return back to salicylic acid, this procedure is called hydrolysis.

The pureness of acetylsalicylic acid can be seen by making a acid/base titration.

The belongingss of the compounds that may be involved in my probe are ;

Acetic Acid


Salicylic acid

Melting point

16.5A A°C







Molar mass

60.05 g mola?’1

180.15 g mola?’1

138.12 g mola?’1


1.08x 10-3

2.72x 10-5

There are one or two solutions that I will be utilizing that necessitate me to believe about safety:

Hydrochloric acid hazard appraisal

Hydrochloric acid is a toxic and caustic acid, there for it should non come in contact with tegument or eyes. Therefore it is best to manage it with neoprene baseball mitts, safety spectacless and good airing as the exhausts can be harmful. If it does acquire into a individuals oculus so it must be flushed instantly with H2O and so medical aid will be needed. And if it is swallowed tonss of H2O should be rummy and so medical is needed. And if it comes in contact with tegument it should be washed off instantly.

Sodium hydrated oxide hazard appraisal

Is a harmful and caustic base, it is a detrimental substance that can do physical harm, if it gets on the tegument it should be washed instantly and if it gets on your apparels these should be removed instantly. Therefore you should ever have on safety spectacless when managing Na hydrated oxide, if it has been swallowed so you should non seek to acquire the victim to puke.

1st Experiment

Weighing boat- 25.55g

Aspirin- 0.62

Ethanol- 10ml

Distilled water- 25ml

3 beads of Phenolphthalein

2.7 milliliter to turn pink

2nd Experiment

Weighing boat- 25.55g

Aspirin- 0.62

Ethanol- 10ml

Distilled water- 25ml

3 beads of Phenolphthalein

6.32 milliliter to turn pink

3rd Experiment

Weighing boat- 25.55g

Aspirin- 0.62

Ethanol- 10ml

Distilled water- 25ml

3 beads of Phenolphthalein

9.1 milliliter to turn pink

I am traveling to transport out an experiment to prove this acetylsalicylic acid. I am traveling to make this by puting up a titration and doing a standard solution of acetylsalicylic acid and titrating it until I see a coloring material alteration which will find how much active ingredient is in the acetylsalicylic acid ( acetyl salicylic acid ) .

My experiment

I ground a aspirin tablet utilizing a stamp and howitzer, doing it into a pulverization. I so weighed the weighing boat it weighed 25.55g this was the same boat I was traveling to utilize all thought the experiments, I so candled it and weighed the land acetylsalicylic acid, it weighed 0.62g. I so put the acetylsalicylic acid into a conelike flask and added 10ml of ethyl alcohol and 25ml of distilled H2O to do a solution. This solution was so assorted until the acetylsalicylic acid dissolved into the solution, nevertheless I found that non all of the spots dissolved. I so measured 25ml of the solution utilizing a pipette and so set it into a clean conelike flask and so added 3 beads of Phenolphthalein

Into the solution this was to move as a index, I filled the pipette with Na hydrated oxide this was so to be titrated into the solution of acetylsalicylic acid, I so titrated it until the solution turned pink. I realised I had do n’t the first experiment wrong when the solution turned pink instantly ; this was because I had used a excessively strong mole of Na hydrated oxide. So I repeated the experiment utilizing 0.30g of acetylsalicylic acid, 10ml of ethyl alcohol and 25ml of distilled H2O into a beaker so stirred it until it had dissolved I so added 3 beads of Phenolphthalein.

To do the Na hydrated oxide I used 0.20g of Na hydrated oxide pellets and 500ml of distilled H2O and assorted it until it was dissolved I so put the Na hydroxide solution into a 500ml conelike flask with a palpebra for later usage.

I am traveling to utilize Phenolphthalein as an index because it goes tap if the PH is above 8.5 there for when I titrate the solution I will be able to halt every bit shortly as the solution turns pink.

How I made the standard solution

I made a standard solution because I am traveling to utilize it in my titration to see the concentration I need to turn the solution pink. I made my standard solution from 0.2g of Na hydrated oxide pellets with 500ml of distilled H2O, I used this sum of the pellets because I wanted to do 0.1 moles of NaOH ( Sodium Hydroxide ) . After I dissolved the pellets into the solution I put it into a volumetric flask to do certain the solution was precisely 500ml and they have tops on them so if I left it would n’t vaporize.


1. 0.1 Mdm-3 NaOH

2. Ethyl intoxicant C2H5OH

3. Aspirin from the closet

4. 150 milliliter flask

5. Burette

6. Mortar and pestle

7. Phenolphthalein index

8. Goggless

9. Pipet

Pure aspirin = 1:1

Main of aspirin = 0.62

= 3.44 ten 10-3 moles

0.1m NaOH = 40

.2 = 40 x.2 = 8g in 1 dm3

4g in 500 cm3

Main = 4.0g

.1m pure 3.44 ten 10-3 = 0.1 ten V


3.44 ten 10-3 = 1 ten 10-2 V 34.4cm3 = V

3.44 ten 10-3 ten 10-3 = 34.4

1 x 10-2

So in theory I should necessitate 34.4 cm3 of NaOH

But mine are merely

6.2 = 18 %


Weight of acetylsalicylic acid 6.2

Number of moles of aspirin = 6.2 = 0.0344062


Concentration of aspirin = 0.344062 ten 1000 = 0.093mdm-3


Weight if NaOH

1mole of NaOH = 23+16+1 = 40

No of moles of NaOH = 0.005 moles

Concentration = 0.0005 ten 1000 = 0.01m NaOH


Consequences from the 3 titrations:

Titration 1


40 = 0.005

2 ten 0.005 = 0.01 moles NaOH

= 0.01 tens 2.7


2.7x 10-6 acetylsalicylic acid

2.7x 10-6 ten 180.2 ( molecular mass of acetylsalicylic acid ) = 0.0049g


= 0.007 % pureness of acetylsalicylic acid

Titration 2


40 = 0.005

2 ten 0.005 = 0.01 moles NaOH

0.01 x 6.32

1000 = 6.32×10-5

6.32×10-5 ten 180.2 = 0.01



Titration 3


40 = 0.005

2 ten 0.005 = 0.01 moles NaOH

0.01 x 9.1

1000 = 9.1 ten 10-5

9.1 x10-5 ten 180.2 = 0.01




This is n’t a really good manner of happening out the pureness of acetylsalicylic acid because it is n’t really accurate and the consequences were all different and rather far off from each other.

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