Which of the following is a true acidic anhydride?

Which blue liquid is obtained on reacting equimolar amounts of two gases at $-30\,^oC$?

An element whose $IUPAC$ name is ununtrium $(Uut)$ belongs to

How many of the following reactions will form $PH_3$ gas?
$(1)$ $Ca_3P_2 + H_2O \to$
$(2)$ $H_3PO_3 \xrightarrow{\Delta} $
$(3)$ $P_4 + NaOH \to$
$(4)$ $H_3PO_4 \xrightarrow{\Delta} $
$(5)$ $HNO_3 + P_4O_{10} \to$
$(6)$ $P_4 + HNO_3 \to$

Which of the following compounds is used as a refrigerant?

Nitrogen is obtained when $NaNO_2$ reacts with