Pure $HNO_3$ is colorless. However,it turns slightly brown when exposed to light due to its decomposition into $.....$.

Pure $N_2$ gas is prepared by:

What are the products formed when ammonia reacts with excess chlorine?

$HNO_3 + P_4O_{10} \rightarrow HPO_3 + A$; the product $A$ is

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 treatment of galena $(PbS)$ with $HNO_3$ produces a gas that is: