Which of the following is obtained by catalytic oxidation of ammonia?

Which one of the following statements is not correct regarding phosphine?

What is expected to happen when phosphine gas is mixed with chlorine gas?

Given below are two statements $:$
Statement $I :$ Nitrogen forms oxides with $+1$ to $+5$ oxidation states due to the formation of $p\pi-p\pi$ bond with oxygen.
Statement $II :$ Nitrogen does not form halides with $+5$ oxidation state due to the absence of $d$-orbital in it.
In the light of given statements,choose the correct answer from the options given below.

Phosphorus pentachloride in the solid state exists as:

For $H_3PO_3$ and $H_3PO_4$,the correct choice is: