Organic Compound

Question 1

Define Foreign/Hetero Elements

Answer 1

Any elements in an organic compound except for carbon and hydrogen

Question 2

Define Sodium Extract Solution

Answer 2

The solution created by heating fusion tube with sodium and filtrate

Question 3

Why are organic compounds fused with sodium before testing for elements?

Answer 3

It is as the elements (N, S, Halogens) are covalently bonded to the compound and sodium helps to convert ithem into ionic forms to make detection easier

Question 4

Give the chemical reaction of Lassaigne’s Test for Nitrogen and Sulphur \?

Answer 4

Na+CN+S=NaCNS NaCNS=NaS+NaCN

In the presence of N and S, sodium thiocyanide is formed during fusion and in presence of excess Na, Sodium Cyanide and Sodium Sulphide is formed

Question 5

Why is sodium extract solution boiled with conc h2 so4?

Answer 5

helps with precipitation of Agcl
Increases the solubility product of agcl
helps to decompose Na2S and NaCN
increases concentration of NO3 ions

Question 6

How do you detect the presence of N and S together in an organic compound?

Answer 6

IF during nitrogen test, instead of blue or green, Blood red color appears, then both N and S are present
rxn: Na+ C + N +S=NaCNS
3NaCNS+FeCL3=Fe(CNS)3 +NaCL