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

Which of the following compounds is not expected to show Lassaigne's test for nitrogen?

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

Give the answers for the Lassaigne test:
$(i)$ If nitrogen and sulphur are both present,what observation is observed?
$(ii)$ If bromine is present,what is the observation?
$(iii)$ In the Lassaigne extract,if black precipitates are not obtained upon adding $CH_3COOH$ and lead acetate,what does this indicate?
$(iv)$ What is the reason for adding $FeSO_4$ to the Lassaigne extract?
$(v)$ Why is the Prussian blue colour observed?
$(vi)$ What does the violet colour with sodium nitroprusside in the Lassaigne extract indicate?

The blue color obtained in the Lassaigne's test is due to the formation of which compound?

An organic compound on heating with $CuO$ produces $CO_{2}$ but no water. The organic compound may be