# 0.8 Organic reactions

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## Objectives

• Synthesis of some important esters.
• Oxidation of a primary alcohol first to an aldehyde and then a carboxylic acid.
• To saponify a typical vegetable oil.

You will be assessed on

• detailed answers required in the lab report.
• the correctness and thoroughness of your observations.

## Introduction

Esters are an important class of organic compounds commonly prepared from the esterification reaction of an organic acid with an alcohol in the presence of a strong mineral acid (usually ${H}_{2}{\text{SO}}_{4}$ ). They are chiefly responsible for the pleasant aromas associated with various fruits, and as such are used in perfumes and flavorings. Some esters also have useful physiological effects. The best known example is the analgesic ("pain killing") and anti-pyretic ("fever reducing") drug acetylsalicylic acid, otherwise known by its trade name aspirin.

Liniments used for topical relief of sore muscles contain the ester methyl salicylate ("oil of wintergreen"), which is prepared from the reaction of methyl alcohol with the acid group of salicylic acid. Methyl salicylate acts as an analgesic and is absorbed through the skin; however, methyl salicylate is also a skin irritant (like many organic substances), which in this instance provides the beneficial side effect of the sensation of warming in the area of the skin where the liniment is applied.

Oxidation of a primary alcohol may yield either an aldehyde or a carboxylic acid, depending on the reaction conditions. For example, mild oxidation of ethanol produces acetaldehyde, which under more vigorous conditions may be further oxidised to acetic acid. The oxidation of ethanol to acetic acid is responsible for causing wine to turn sour, producing vinegar.

A number of oxidising agents may be used. Acidified sodium dichromate (VI) solution at room temperature will oxidise primary alcohols to aldehydes and secondary alcohols to ketones. At higher temperatures primary alcohols are oxides further to acids.

The dichromate solution turns from the orange color of the ${\text{Cr}}_{2}{O}_{7}^{2-}$ (aq) to the blue color of the ${\text{Cr}}^{3+}$ (aq). This color change is the basis for the "breathalyser test". The police can ask a motorist to exhale through a tube containing some orange crystals. If the crystals turn blue, it shows that the breath contains a considerable amount of ethanol vapor.

Soaps are produced by the reaction of metallic hydroxides with animal fats and vegetable oils. The major components of these fats and oils are triglycerides. Triglycerides are esters of the trihydroxy alcohol called glycerol and various long-chain fatty acids. Tristearin is a typical triglyceride. Upon reaction with sodium hydroxide, the ester bonds of tristearin are broken. The products of the reaction are the soap, sodium stearate, and glycerol. This type of reaction is called saponification (Greek: sapon, soap) and it is depicted below.

Soap is made commercially by heating beef tallow in large kettles with an excess of sodium hydroxide. When sodium chloride is added to this mixture (called the "saponified" mixture), the sodium salts of the fatty acids separate as a thick curd of crude soap. Glycerol is an important by-product of the reaction. It is recovered by evaporating the water layer. The crude soap is purified, and coloring agents and perfumes are added to meet market demands.

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
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