The correct sequence of decrease in the bond angle of the following hydrides is

Why $NH_3$ cannot be dried by $H_2SO_4$,$P_2O_5$,and $CaCl_2$?

The reaction of nitric oxide with ozone produces which gases?

Which of the following reaction products are represented correctly?
$(a)\ P_4 + 3NaOH(dil) + 3H_2O \to PH_3 + 3NaH_2PO_2$
$(b)\ 3Br_2 + 6NaOH(conc) \to 5NaBr + NaBrO_3 + 3H_2O$
$(c)\ NCl_3 + 3H_2O \to NH_3 + 3HOCl$
$(d)\ I_2 + 2NaOH \to NaI + NaOI + H_2O$
$(e)\ Al_4C_3 + 12H_2O \to 4Al(OH)_3 + 3CH_4$
$(f)\ N_2O_4 + H_2O \to HNO_3 + HNO_2$
$(g)\ NH_4NO_3 + NaOH \to NH_3 + NaNO_3 + H_2O$
Correct options are:

When concentrated $H_2SO_4$ is heated with $KNO_3$,brown fumes are evolved. These fumes are due to:

In the Ostwald's process for the manufacture of $HNO_3$,the catalyst used is