Bromine unsaturation test- how to find that a compound is unsaturated or not [practically]

 

Bromine unsaturation test- how to find that a compound is unsaturated or not [practically]

It is very interesting to have practical knowledge along with theory. The main purpose behind having education in pharmacy to have practical knowledge of pharmacy. But most of the students don’t consider practicals seriously and focus on theory. It gives good marks but not the spark in mind. So ya let’s have a look on how you can find a compound is unsaturated or saturated practically and theory behind it.

What is unsaturation?

Before going in much detail let us know what is saturation and unsaturation. Basically saturation means “satisfied” and unsaturated means “not satisfied”. Saturation and unsaturation terminology comes in various subjects with different meanings. But here I am telling you regarding the chemistry only.

When an compound have one or more double or triple bond then it is called unsaturated. Compound containing only single bonds are called as saturated.

Single bond compounds are called saturated because they are satisfied with their own atoms and hence they don’t allow to add any other atoms to them. Therefore their strong single bond is not broken easily and they don’t undergo addition reaction.

While unsaturated compounds are not satisfied and allow other atoms to add in their structure. And therefore their weak bonds are broken easily to undergo addition reaction.

Bromine unsaturation test [practical]:

Here we know now that what is saturated and what is unsaturated compound. Now can we say that a compound is saturated or unsaturated by just seeing it with our naked eyes. The answer is NO. Thus the question must arise in your mind that then how you can detect it. So answer is bromine unsaturation test. Let us see procedure for the bromine unsaturation test.

Note: bromine unsaturation test is applicable only to water soluble compounds.

Procedure:

1.       Take a pich of water soluble compound to be tested in a test tube 

2.       Now dissolve it in 2 ml distilled water in that test tube

3.       Then add 2 drops of (orange coloured)bromine water to the test tube

4.       Shake well

5.       See the change

Observation and conclusion:

Orange Colour of bromine water disappears in case of unsaturated compounds.

The solution’s orange colour remain unchanged in case of saturated compounds.

Bromine unsaturation test theory:

After discussing practical you must be wondered why the colour changed in the unsaturated compound and in case of saturated compound it doesn’t changed. The answer you know already if you have read the first point of our discussion i.e. what is unsaturation.

The colour of bromine water changed in case of unsaturated compounds, that means there must be any chemical reaction happened. Ya As we discussed earlier that unsaturated compound undergo addition reactions. And saturated compounds don’t undergo any addition reaction.

When we added bromine water that means we added the bromine to the compound. When bromine was added to compound , if our compound is unsaturated then it must undergo addition reaction and bromine gets added across the double bonds of unsaturated bond. And therefore the chemical reaction occurs and colour of bromine water changes. In contrast when we add bromine to a single bond i.e. saturated compound then id doesn’t undergo any reaction thus colour of bromine water does not change.

So that was all about Bromine unsaturation test- how to find that a compound is unsaturated or not [practically].

Hope you enjoyed it and had some knowledge from it. So guys if you liked it and learned something or you know something more then share with us in comment box and also if you have a suggestion then don’t forget to comment. Have a nice day.