Question

The set of correct statements is :
(i) Manganese exhibits +7 oxidation state in its oxide. 
(ii) Ruthenium and Osmium exhibit +8 oxidation in their oxides. 
(iii) Sc shows +4 oxidation state which is oxidizing in nature. 
(iv) Cr shows oxidising nature in +6 oxidation state.

• A. (ii) and (iii)
• B. (i), (ii) and (iv)
• C. (ii), (iii) and (iv)
• D. (i) and (iii)

Answer 1

The Correct Option is B

Let's analyze each statement to determine which ones are correct:

1. Manganese exhibits +7 oxidation state in its oxide.
   Manganese (Mn) can exist in oxidation states ranging from +2 to +7. In the compound manganese heptoxide (Mn₂O₇), manganese is present in the +7 oxidation state. This statement is correct.
2. Ruthenium and Osmium exhibit +8 oxidation in their oxides.
   Both ruthenium (Ru) and osmium (Os), which are transition metals, are known to exhibit a +8 oxidation state. For instance, osmium tetroxide (OsO₄) is a well-known compound where osmium is in the +8 state. Ruthenium tetroxide (RuO₄) is another example. This statement is correct.
3. Sc shows +4 oxidation state which is oxidizing in nature.
   The element scandium (Sc) typically shows a +3 oxidation state and not +4. The +3 state is stable, and there is no common +4 state for scandium. This statement is incorrect.
4. Cr shows oxidizing nature in +6 oxidation state.
   Chromium (Cr) in the +6 oxidation state is often found in compounds like chromate (CrO₄^2-) and dichromate (Cr₂O₇^2-), both of which are known for their oxidizing properties. Hence, this statement is correct.

Therefore, the correct set of statements is: (i), (ii), and (iv).