Please Answer ALL. Thanks. a) The names, melting points and structures of two fa
ID: 534894 • Letter: P
Question
Please Answer ALL.
Thanks.
a) The names, melting points and structures of two fatty acids are shown below. Both compounds consist of a carboxylic acid group and a hydrocarbon chain of 18 carbon atoms. Explain the difference in melting point between the two compounds. b) Saponification of triglycerides gives glycerol and fatty acid salts as shown in the equation below. The groups R_1, R_2 and R_3 represent hydrocarbon chains that may be the same or different Saponification is actually a hydrolysis reaction. Explain what a hydrolysis reaction is and the role of sodium hydroxide in this process.Explanation / Answer
oleic acid has a cis C=C bond with a bent or U shape which has the ability to pack less denser than the straight chains hence less energy is required to overcome the molecular forces that allow the compound to be in solid form therfore a lower temperature is required to turn the solid to liquid. While in the stearic acid all the carbons are saturated and they take a straight chain form which pack closer which consumes more energy to break hence higher melting point.
b) Hydrolysis reaction is a chemical process in which water is added to the compound or substance which causes substance and water molecule to spilt and thereby the parent molecule gain a hydrogen ion.
NaOH forms a hard soap. It forms a lye solution with the liquids and when mixed with fats and oils causes saponification. In this process the hydroxide ion attacks the carbonyl group of ester forming an orthoester followed by expulsion of alkoxide gives a carboxylic acid and the proton from acid is transferred to the alkoxide ion which results in alcohol (glycerol) formation.