There is a murder, which shocked the entire town. The dead body contain the blood smear of other person. The police suspected two persons. Name the method used to identify the murderer.

There are two compounds of sodium whose formulae are (anhydrous form) different by one H- atom. Both the compounds can be prepared by the same process. One compound can be used for washing purpose and other one can be used in fire extinguishes. (a) Identify the compounds? (b) Name the method of preparation?