What is the correct order of acidic character for the following oxides: $SO_2, CO_2, CO, N_2O_5$?

The nature of the two oxides of nitrogen,$X$ and $Y$,formed in the reaction of sodium nitrite $(NaNO_2)$ with hydrochloric acid $(HCl)$ is:

Which of the following represents the correct order of acidic strength?

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

Give the preparation of phosphorus trichloride and phosphorus pentachloride.

Given below are two statements:
Statement $I$: The halogen that makes the longest bond with hydrogen in $HX$ has the smallest covalent radius in its group.
Statement $II$: $A$ group $15$ element's hydride $EH_3$ has the lowest boiling point among corresponding hydrides of other group $15$ elements. The maximum covalency of that element $E$ is $4$.
In the light of the above statements, choose the correct answer from the options given below.