Preparation of Antifebrin

Ethanoic anhydride/Acetic anhydride

Preparation of Antifebrin

1st beaker = 1.0g exactly of phenyl ammonium and 30cm3 water mixed

2nd Beaker = 6.0g exactly of sodium ethanoate and 25cm3 distilled water

Added 2cm3 ethanoic anhydride to 1st beaker. Appeared Immiscible.
Added the 2nd beaker to the 1st and a white precipitate was formed.

Mixture filtered under reduced pressure, to leave the white precipitate, which is now crude antifebrin. Cold water poured over the top to rinse the crude antifebrin has no effect.

Just over 25cm3 hot water, precipitate fully dissolves to clear liquid.
Liquid placed into ice bath, and the precipitate returns white, but finer.

Dried the product and placed a small amount aside to record melting point.

Melting point: 114C to 116C

Predicted mass:

1.0g/129.5g = 0.007722 moles

Equation:

C6H5NH3+Cl- + (CH3CO)2O = CH3CONHC6H5 + CH3COOH + HCL

Molar ratio:

1        +        1        =        1        +        1        +        1

Mass:

1.0        +        /        =        1.0        +        /        +        /

Number of moles of Phenylammonium = Number of moles CH3CONHC6H5

0.007722 = 0.007722

0.007722 x 135g = 0.945g Predicted mass of CH3CONHC6H5

Actual:

0.40

Percentage Mass:

Actual/Predicted = 0.4/0.945 = 0.42