We are getting will be the blue colored product and when this one of the carbons of the olefinic linkage is tertiary and the second and the second carbon of the olefinic linkage is secondary here you can see that this is the hydrogen atom so this carbon is secondary in nature when there is serve this difference of for the carbon nature then the addition of nitrosyl chloride will result into the addition product which is a colorless product so by the distinction of the color we can ascertain the linkage of the carbon-carbon double bond that is whether it is present in Etosha form or it is enough secondary form again this nitrosyl chloride the addition of this Tilden reagent basically takes place according to the Marconi cough rule then comes up our acid addition/acids can also be used to determine the amount of unsaturation in a terpenoid molecule with parasite star p nodes containing the olefinic double bonds. They form the epoxides here you can see in the reaction when this unsaturation is present in the terpenoid and when it is reacted with the / s in / acid contains one oxygen more than the acid then this oxygen will be absorbed by this olefinic linkage and it will form the epoxide which is a cyclic ether a known amount of terpenoid is treated with an excess of pur acid that is a part helices it in some cases and then the unused amount of the acid is determined volumetrically from the amount of Paris it's used the number of olefinic double bonds can be determined quantitatively in order to detect the presence of the conjugated system of double bonds in a terpenoid the diels-alder reaction is used which is a general reaction used for the presence of conjugation conjugated systems in the natural products then comes a number of rings that how many rings are present in that a particular hydrocarbon or whether it is a cyclic hydrocarbon. Now from the steps which we have discussed that the molecular formula the nature of the oxygen the unsaturation after these all the number of double bonds and the nature of functional groups after discussing all then they then the step comes the number of rings it is possible to find out the molecular formula of a parent saturated hydrocarbon of a terpenoid which own comparison with the formula as we have shown in the table it reveals the information about the number of Rings present in the terpenoids if after after calculating the molecular formula if the hydrocarbon formula comes cnh2n plus 2 then the compound would be acyclic it comes cnh2n then the compound will be mono cyclic it means it will contain the one ring if it comes C and H 2 and minus 2 it will be by cyclic and if it comes C n H 2 and minus 4 it will be try cyclic and if it comes C and H 2 and minus 6 6 it will be tetracyclic for this we have taken one example the molecular formula of CTL is c10 at 1600 which contains the 2 double bonds and 1 oxygen atom as a carbonyl group does the molecular formula of the parent hydrocarbon would be c10 at 1600 which is equivalent to C 10 H 16 plus the 4 hydrogen's which are basically because of the 2 double bonds present and since 1 carbon oxygen which is a carbonyl nature.