In what form is nitrogen estimated in the Dumas method?

Which gas is liberated in Dumas method?

An organic compound is estimated through Dumas method and 1 mole of the compound evolved 6 moles of CO_2 . 4 moles of H_2 O and 1 mole of N_2 gas . The formula of the compound is

In Dumas method, nitrogen is estimated as

Give the principle of estimation of nitrogen by Dumas method.

In Kjeldahl's method, nitrogen is estimated as

A bird excrates nitrogenous waste materials in the form of?

How many ml N_2 gas (at NTP) will be obtained from 1.2 g urea by the Dumas method?