1. explain why cu+ ion is not stable in aqueous solution?
2. explain why Ce4+ is a stronger oxidizing agent?
3. which is stronger reducing agent Cr2+, or Fe2+ and why?
4. Describe the oxidizing property of KMnO4 in neutral of alkaline medium for its reaction with iodide irons and thiosulphate irons.
5. What is magnetic moment of Cr3+ ion?
6. why do transition metals form alloys?
7. Why is V2+ is more Stable than V3+
1. Cu+ ion oxidizes and reduces simultaneously in aqueous solution to give Cu2+ and Cu ions. Therefore Cu+ ion is unstable in aqueous solution and it disproportionates readily to Cu2+ and Cu ions.
2. Ce belongs to the lanthanoid series. In lanthanoids +3 oxidation state is the most stable. Ce+4 therefore tends to acquire +3 oxidation state by undergoing reduction and therefore is a very strong oxidizing agent.
3. Cr2+ is a stronger reducing agent as compared to Fe2+ as after loss of one electron it acquires half filled d3 configuration as - Cr3+.
4. In neutral medium KMnO4 is weakly oxidizing. Whereas in alkaline medium it is strongly oxidizing.
2KMnO4 + H2O → 2KOH + 2MnO2 + 3O
MnO4– + 2H2O + 3e– → MnO2 + 4OH–
KOH renders the solution alkaline.
Iodide ions in a neutral or alkaline solution of KMnO4 are converted to iodate ions.
2KMnO4 + H2O + KI → 2MnO2 + 2KOH + KIO3
Thiosulpahte ions reduce KMnO4 to give Mn2+ ions - which are colorless in solution.
5. Magnetic moment of Cr3+ - 0.6 to 0.775.
6. Alloys are homogenous solid solutions with atoms of one metal distributed randomly among atoms of other metals. In order for metals to form alloys they should be of comparable size and should be similar in terms of atomic radii. Since transition metals have similar radii and they have properties comparable to each - they readily form alloys.
7. V2+ is not stable as compared to V3+. Among the 5 oxidation states exhibited by Vanadium, +3 is the most stable.