Concentrated nitric acid,upon long standing,turns yellow-brown due to the formation of

$A$ gas at low temperature does not react with most compounds. It is almost inert and is used to create an inert atmosphere in bulbs. The combustion of this gas is exceptionally an endothermic reaction. Based on the given information,we can conclude that the gas is

Which of the following is a mixed anhydride?

Nitric acid forms an oxide of nitrogen on reaction with $P_{4}O_{10}$. Write the reaction involved. Also,write the resonating structures of the oxide of nitrogen formed.

Explain the molecular structure and properties of phosphorus pentachloride $(PCl_5)$.

What are the number of $P - O - P$ bridges in phosphorus pentoxide and phosphorus trioxide,respectively?