S.4Chemistry 2nd Term Project
Be a Chemical Analyst-Analysis on ethnoic acid.
This experiment aims at determining the percentage by mass of ethanoic acid(CH3COOH) in a commercial vinegar using titration method.
Chemical reaction involved:
CH3COOH(aq) + NaOH(aq)→ NaCH3COO(aq) + H2O(l)
An electronic balance, a 10.0cm3 pipette, a 25.0cm3 pipette, a pipette filler, a 250.0cm3 volumetric flask, a burette, stand and clamp, a conical flask, a white tile, 3 large beakers, a small beaker, a dropper, a boiling tube, a rinsing bottle
0.1M NaOH(aq),phenolphthalein indicator, commercial vinegar (5% acidity), distilled water
Part1: The density of the commercial vinegar was found.
A small breaker was put on an electronic balance and the reading of the balance was set to zero gram.
10.0cm3 of the commercial vinegar was pipetted into a small beaker.
The vinegar was weighed with an electronic balance.
And the density of the vinegar was known as 1gcm-3.
Part2: The commercial vinegar was diluted 10 times.
A 25.0cm3 pipette was washed with distilled water and then with the commercial vinegar.
25.0cm3 of the commercial vinegar was pipetted into a 250.0cm3 volumetric flask
Distilled water was added to the volumetric flask and made up to right before the graduation mark.
A dropper was used to add distilled water into the volumetric flask, then the solution was made up to the graduation mark and the vinegar was diluted 10 times.
Part:3 The diluted vinegar was titrated against standard NaOH(aq).
25.0cm3 of dilute commercial vinegar solution was transferred from the 250.0cm3 volumetric flask into a conical flask with the washed 25.0cm3 pipette.
A few drops of phenolphthalein was added into the diluted vinegar as indicator.
A burette was washed with distilled water and then the standard NaOH(aq).And then was filled with standard NaOH(aq).
The conical flask was placed under the burette and...
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