When air is passed through potash and then pyrogallol, the components are noble gases,

Godsown26

3 months ago

The correct answer is B. oxygen and nitrogen. When air is passed through potash (typically potassium hydroxide) and then pyrogallol (specifically alkaline pyrogallol), these chemicals act as selective absorbers to isolate the inert components of air.
Why other options are incorrect
A. oxygen and carbon (IV) oxide: These are the gases absorbed by the reagents, not the ones that remain.
C. nitrogen and water vapour: While nitrogen remains, water vapour is typically removed by drying agents like fused calcium chloride before or during such analyses to ensure only dry gases are measured.
D. water vapour and carbon (IV) oxide:
is removed by the potash, and water vapour is not a primary component left after standard gas analysis involving these reagents.
E. oxygen and water vapour: Oxygen is removed by the pyrogallol, and water vapour is not the principal gas remaining.