The minimum temperature required for a non-catalytic reaction between $N_2$ and $O_2$ is (in $K$)

Among the oxides of nitrogen,$N_2O$,$NO$,and $NO_2$,molecules with unpaired electrons are:

What is the solubility of phosphine $(PH_3)$ in water?

What is the number of oxygen atoms attached to each phosphorus atom in $P_4O_{10}$?

Which of the following ions does not exist in an aqueous solution?

Identify the $INCORRECT$ statement$(s)$ among the following:
$(I)$ Moist ammonia gas can be dried by using anhydrous $CaCl_2$
$(II)$ Phosphine is a weaker base than ammonia
$(III)$ $R_3SiCl$ produces very complex cross-linked polymeric silicone on hydrolysis
$(IV)$ When metallic copper reacts with $6 \ M$ $HNO_3$,$NO_2$ is the only product