When calomel reacts with $NH_4OH$ solution,the compound formed is

Which of the following is metaphosphoric acid?

Dilute nitric acid on reaction with $Ag$ liberates

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.

$\underbrace{2NO + O_2}_{(X)} \rightleftharpoons \underbrace{2NO_2}_{(Y)} \underset{heat}{\overset{cold}{\longleftrightarrow}} \underbrace{N_2O_4}_{(Z)}$
$X, Y$ and $Z$ can be described as:

What is formed when $PCl_3$ reacts with water?