Problem 19
Carbon is in the lowest oxidation state in (a) \(\mathrm{CH}_{4}\) (b) \(\mathrm{CCl}_{4}\) (c) \(\mathrm{CF}_{4}\) (d) \(\mathrm{CO}_{2}\)
Problem 20
Which of the following is a decreasing order of oxidation states of the central atoms? (a) \(\mathrm{PCl}_{5}, \mathrm{HIO}_{4}, \mathrm{Cl}_{2} \mathrm{O}_{7}^{2-}, \mathrm{Cl}_{2} \mathrm{O}\) (b) \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}, \mathrm{Cl}_{2} \mathrm{O}, \mathrm{HIO}_{4}, \mathrm{PCl}_{5}\) (c) \(\mathrm{HIO}_{4}, \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}, \mathrm{PCl}_{5}, \mathrm{Cl}_{2} \mathrm{O}\) (d) \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}, \mathrm{HIO}_{4}, \mathrm{Cl}_{2} \mathrm{O}, \mathrm{PCl}_{5}\)
Problem 21
Which compound amongst the following has the highest oxidation number of Mn? (a) \(\mathrm{KMnO}_{4}\) (b) \(\mathrm{K}_{2} \mathrm{MnO}_{4}\) (c) \(\mathrm{MnO}_{2}\) (d) \(\mathrm{Mn}_{2} \mathrm{O}_{3}\)
Problem 24
The oxidation number of nitrogen in \(\left(\mathrm{N}_{2} \mathrm{H}_{5}\right)^{+}\)is (a) \(-2\) (b) \(+2\) (c) \(+3\) (d) \(-3\)
Problem 27
Which compound among the following has lowest oxidation number of chlorine? (a) \(\mathrm{HClO}_{4}\) (b) \(\mathrm{HClO}_{3}\) (c) \(\mathrm{HCl}\) (d) \(\mathrm{HOCl}\)
Problem 30
Oxidation \(\quad\) number \(\quad\) of \(\quad\) sulphur in peroxomonosulphuric acid \(\left(\mathrm{H}_{2} \mathrm{SO}_{5}\right)\) is (a) \(+4\) (b) \(+2\) (c) \(+6\) (d) \(-2\)
Problem 32
The oxidation state of \(\mathrm{Fe}\) in \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) is (a) \(+2\) (b) \(+3\) (c) \(+4\) (d) \(+6\)
Problem 34
The correct sequence of the oxidation state of underlined elements is \(\mathrm{Na}_{2}\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NO}\right], \mathrm{K}_{2} \mathrm{TaF}_{7}, \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}, \mathrm{Na}_{2} \mathrm{~S}_{4} \mathrm{O}_{6}, \mathrm{~N}_{3} \mathrm{H}\) (a) \(+3,+5,+5,+2.5,-\frac{1}{3}\) (b) \(+5,+3,+5,+3,+\frac{1}{3}\)
Problem 35
What are the oxidation states of phosphorus in the following compounds? \(\mathrm{H}_{3} \mathrm{PO}_{2}, \mathrm{H}_{3} \mathrm{PO}_{4}, \mathrm{Mg}_{2} \mathrm{P}_{2} \mathrm{O}_{7}, \mathrm{PH}_{3}, \mathrm{HPO}_{3}\) (a) \(+1,+3,+3,+3,+5\) (b) \(+3,+3,+5,+5,+5\) (c) \(+1,+2,+3,+5,+5\) (d) \(+1,+5,+5,-3,+5\)
Problem 36
In which of the following compounds carbon is in highest oxidation state? (a) \(\mathrm{CH}_{3} \mathrm{Cl}\) (b) \(\mathrm{CCl}_{4}\) (c) \(\mathrm{CHCl}_{3}\) (d) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\)
