There is no direct test for the detection of which element in an organic compound?

There is no direct test for the detection 0? following in organic compound

Ammonium molybdate is used for detection of which element in organic compound :

In the Lassaigne's test for the detection of nitrogen in an organic compound, the appearance of blue coloured compound is due to

Soda lime test is used to detect one of the following element of organic compound