Magnesium metal when burns in air gives a mixture of its nitride & oxide. When dissolved in water the solution becomes basis because of `NH_(3)` & metal hydroxide. 39.2 gm sample of pure magnesium is reacted with 82.1 litre of air (containing only `N_(2) & O_(2)` in 4:1 molar ratio) at 1 atm & 300 K to form a mixture of nitride & oxide labelled as micture I such that all magnesium & one of the gases get completely consumed. this mixture is dissolved in water which is labelled as micture II. based on this information, answer the questions that follows.
which gas will be left unreacted in air & by how much ?

Options

A. `N_(2(g)), 7.7/3` moles
B. `O_(2), 0.6` moles
C. `N_(2(g)), 2` moles
D. `O_(2),1.7/3` moles

Answer

A