Which of the following compounds will give a positive Lassaigne's test for both nitrogen and halogen?

The volume of nitrogen is measured by which apparatus in the Dumas method?

Given below are two statements :
Statement $I$ : In Lassaigne's Test,when both nitrogen and sulphur are present in an organic compound,sodium thiocyanate is formed.
Statement $II$ : If both nitrogen and sulphur are present in an organic compound,then the excess of sodium used in sodium fusion will decompose the sodium thiocyanate formed to give $NaCN$ and $Na_{2}S$.
In the light of the above statements,choose the most appropriate answer from the options given below.

Explain the reason for the fusion of an organic compound with metallic sodium for testing nitrogen,sulphur,and halogens.

Name the methods used for determining the molecular mass of organic compounds.

How is the silver halide obtained from an organic compound distinguished?