Which gas is liberated in Kjeldahl's method?

Which gas is liberated in Dumas method?

A sample of 0.50 g of an organic compound was treated according to Kjeldahl's method. Ammonia evolved was absorbed in 50 mL of 0.5 M H_2SO_4 . The residual acid required 60 mL or 0.5 M NaOH solution for neutralisation. Find the percentage composition of nitrogen in the compound.

Briefly explain the principle involved in Kjeldahl's method for the estimation of nitrogen.

Which is the gas liberated when metals react with dilute acids?

Which is the gas liberated when metals react with dilute acids?