Lapis lazuli is

Given below are two statements :
Statement $-I :$ The pentavalent oxide of group $-15$ element,$E_2O_5$,is less acidic than trivalent oxide,$E_2O_3$,of the same element.
Statement $-II :$ The acidic character of trivalent oxide of group $15$ elements,$E_2O_3$,decreases down the group.
In light of the above statements,choose the most appropriate answer from the options given below.

Consider the following reaction:
$A +$ alkali $\rightarrow B$ (Major Product)
If $B$ is an oxoacid of phosphorus with no $P-H$ bond,then $A$ is ..... .

Concentrated $HNO_3$ is a yellow-colored liquid due to:

Which of the following oxides of nitrogen is the anhydride of $HNO_3$?

In which of the following ranges does nitrogen exhibit its various oxidation states?