Common Oxidation States

Q.

When acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ solution is added to ${\mathrm{Sn}}^{2+}$ salt, then ${\mathrm{Sn}}^{2+}$ changes to:

1. $\mathrm{Sn}$

2. ${\mathrm{Sn}}^{+}$

3. ${\mathrm{Sn}}^{3+}$

4. ${\mathrm{Sn}}^{4+}$

Q. In acidic medium, $H_2{O}_2$ changes $C{r}_2{O}_7^{2-}$ to $Cr{O}_5$ which has two ( - O - O -) bonds. Oxidation state of Cr in $Cr{O}_5$ is

1. 5
2. 3
3. 6
4. -10

Q. The oxidation state of chromium in the final product formed by the reaction between KI and acidified potassium dichromate solution is

1. +4
2. 6
3. 2
4. 3

Q. Oxidation states of the metal in the minerals haematite and magnetite, respectively, are
(IIT-JEE, 2011)

1. II, III in haematite and III in magnetite
2. II, III in haematite and II in magnetite
3. II in haematite and II, III in magnetite
4. III in haematite and II, III in magnetite

Q. Assuming complete ionization, same moles of which of the following compounds will require the least amount of acidified $KMn{O}_4$ for complete oxidation?

1. $Fe{C}_2{O}_4$
2. $Fe(N{O}_2{)}_2$
3. $FeS{O}_4$
4. $FeS{O}_3$

Q. An element which never has a positive oxidation number in any of its compounds

1. Boron
2. Oxygen
3. Chlorine
4. Fluorine