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Preparing Benzoic Acid from Benzylalcohol

Satisfactory Essays
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]