When copper metal is treated with cold and dilute nitric acid,it forms

Which of the following substances releases nitrogen gas upon thermal decomposition?

Which of the following oxides is paramagnetic?

Which of the following has the highest boiling point?

Draw the structures of the following oxoacids of phosphorus:
$(i)$ Orthophosphoric acid $(H_{3}PO_{4})$
$(ii)$ Pyrophosphoric acid $(H_{4}P_{2}O_{7})$
$(iii)$ Orthophosphorus acid $(H_{3}PO_{3})$
$(iv)$ Hypophosphorus acid $(H_{3}PO_{2})$
$(v)$ Cyclotrimetaphosphoric acid $((HPO_{3})_{3})$
$(vi)$ Polymetaphosphoric acid $((HPO_{3})_{n})$

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