Total Fatty Matter Of Washing Soap

AIM:
To determine the Total Fatty Matter (TFM) of Washing Soap

PRINCIPLE:
TFM is determined by titrating fatty acids by means of HCl  &; extracting oil & acid with ether.

APPARATUS:

• 2 separating funnels
• 250ml beakers: 2
• 100ml conical flask : 1
• Electronic balance.

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REQUIREMENTS:

• Soap sample
• Hot water
• 1:1 HCl
• Ether

PROCEDURE:

• The washing bar soap is made into small slices.( fig: already shown in the previous post)
• weigh 5gm of thoroughly mixed soap sample.

• Note the weight taken & add the soap sample into a separating funnel.

• From a beaker add 30ml hot water & mix well.

• Excess 1:1 HCl is added  to decompose the soap, till acids float as a clear layer on the top, cool & add 50ml ether,mix well & separate.
• The aqueous layer is taken in another separating funnel & extract with ether.
• The combined ether extract were washed  thrice with water to remove mineral acids.
• The contents are taken in a previously weighed 100ml conical flask.

• Ether distilled off & dried to constant weight.

CALCULATION

From the weight of soap taken, weight of conical flask+ sample & the weight of conical flask alone, the Total Fatty Matter of Washing Soap can be calculated.

I was able to calculate the TFM of sunlight bar soap as 55.096.