Preparing Benzoic Acid from Benzylalcohol
Planning (a)
Problem
The aim of this experiment is to synthesize benzioc acid, with the
highest possible yield, by oxidizing benzylalcohol.
Hypothesis
We expect the percentage yield to be about 50% due to several
processes such as cooling and filtering.
Possible Variables
- Time
- Temperature (of water)
- Filter
Planning (b)
Apparatus/ Materials
- Round bottomed flask under reflux
- benzylalcohol
- HCl
- Na2O4
- Büchner funnel
- beakers
- sodium carbonate
Procedure
The benzioc acid is synthesized by heating benzylalcohol in a round
bottomed flask under reflux. In addition to that, we use Na2O4 as a
oxidizing agent. After that, we use HCl to precipitate it. After the
some time, we filter it through a Büchner funnel before it is
recrystallized and filtered again. The mass was recorded as it was
dry.
By adding sodium carbonate, we will now test whether what obtained is
benzoic acid or not, because one can observe bobbles if it is an acid.
After that we burn it to test if it is aromatic. Soot would be
possible to obtain if it was to be aromatic.
Data Collection
Mass of benzylalcohol
3.991 grams
Mass of flask (before adding benzoic acid)
95.47 grams
Mass of flask (after adding benzoic acid)
96.68 grams
After the addition of sodium carbonate
Bubbles were obtained
After burning it
Soot was obtained
Data Processing
Mass of benzoic acid
96.68 – 95.47 = 1.21 grams
We assume that the reaction goes to completion which would mean that
one mole of benzylalcohol should give one mole of benzoic acid.
Hence, the theoretical yield is 100% by amount of mol.
Molar mass
Benzylalcohol
108 g/mol
Benzoic acid
122 g/mol
Initial amount of benzylalcohol: [IMAGE]
Planning (a)
Problem
The aim of this experiment is to synthesize benzioc acid, with the
highest possible yield, by oxidizing benzylalcohol.
Hypothesis
We expect the percentage yield to be about 50% due to several
processes such as cooling and filtering.
Possible Variables
- Time
- Temperature (of water)
- Filter
Planning (b)
Apparatus/ Materials
- Round bottomed flask under reflux
- benzylalcohol
- HCl
- Na2O4
- Büchner funnel
- beakers
- sodium carbonate
Procedure
The benzioc acid is synthesized by heating benzylalcohol in a round
bottomed flask under reflux. In addition to that, we use Na2O4 as a
oxidizing agent. After that, we use HCl to precipitate it. After the
some time, we filter it through a Büchner funnel before it is
recrystallized and filtered again. The mass was recorded as it was
dry.
By adding sodium carbonate, we will now test whether what obtained is
benzoic acid or not, because one can observe bobbles if it is an acid.
After that we burn it to test if it is aromatic. Soot would be
possible to obtain if it was to be aromatic.
Data Collection
Mass of benzylalcohol
3.991 grams
Mass of flask (before adding benzoic acid)
95.47 grams
Mass of flask (after adding benzoic acid)
96.68 grams
After the addition of sodium carbonate
Bubbles were obtained
After burning it
Soot was obtained
Data Processing
Mass of benzoic acid
96.68 – 95.47 = 1.21 grams
We assume that the reaction goes to completion which would mean that
one mole of benzylalcohol should give one mole of benzoic acid.
Hence, the theoretical yield is 100% by amount of mol.
Molar mass
Benzylalcohol
108 g/mol
Benzoic acid
122 g/mol
Initial amount of benzylalcohol: [IMAGE]