Which of the following mixtures of two gases in equimolar amounts will produce a blue liquid at $-30\,^oC$?

$PCl_3$ reacts with water to form:

In $P_4$ (tetrahedral) molecule:

Which of the following are the correct orders of stability of oxidation states of cations?
$(a) \ Pb^{+2} > Pb^{+4}, Tl^{+1} < Tl^{+3}$
$(b) \ Bi^{+3} < Sb^{+3}, Sn^{+2} < Sn^{+4}$
$(c) \ Pb^{+2} > Pb^{+4}, Bi^{+3} > Bi^{+5}$
$(d) \ Tl^{+3} < In^{+3}, Sn^{+2} > Sn^{+4}$
$(e) \ Sn^{+2} < Pb^{+2}, Sn^{+4} > Pb^{+4}$
$(f) \ Sn^{+2} < Pb^{+2}, Sn^{+4} < Pb^{+4}$

The nitrogen-containing compound produced in the reaction of $HNO_3$ with $P_4O_{10}$:
$(A)$ can also be prepared by the reaction of $P_4$ and $HNO_3$
$(B)$ is diamagnetic
$(C)$ contains one $N-N$ bond
$(D)$ reacts with $Na$ metal producing a brown gas

Which of the following oxides does not give any oxyacid in aqueous solution?