Transition Elements

Step 1: Understand the formula for magnetic moment.
The magnetic moment for a transition metal ion is given by the formula: where is the number of unpaired electrons. For Mn , the electron configuration is , so there are 5 unpaired electrons. Substituting into the formula: Thus, the correct answer is (B).

Titanium in its oxidation state has an electronic configuration equivalent to , devoid of d-electrons. In transition metals, color typically originates from d-d electron transitions. However, the lack of d-electrons in means that these transitions are absent, resulting in colorless compounds.

Reducing Agents in Blast Furnace
In the reduction zone of a blast furnace, the primary reducing agent for converting iron oxides (like Fe O ) to molten iron (Fe) is carbon monoxide (CO). Carbon (in the form of coke) also acts as a reducing agent at higher temperatures.
Chemical Equations

[(i)] Carbylamine Reaction for Ethylamine: This is a test for primary amines. Ethylamine is heated with chloroform (CHCl ) and alcoholic potassium hydroxide (KOH) to form ethyl isocyanide, which has a foul smell.
[(ii)] Hoffmann Bromamide Degradation for Acetamide: This reaction converts an amide to a primary amine with one less carbon atom. Acetamide is treated with bromine in an aqueous or ethanolic solution of sodium hydroxide.

Part 1: General Electronic Configuration of 3d Series
The 3d series consists of elements from Scandium (Sc, Z=21) to Zinc (Zn, Z=30). The differentiating electron enters the 3d orbital. The general electronic configuration for the elements of the 3d series is:
where [Ar] represents the core configuration of Argon.

Part 2: Structures of Sulphuric Acid and Thiosulphuric Acid

Sulphuric Acid (H SO ): Sulphur is the central atom, bonded to two hydroxyl (-OH) groups and two oxygen atoms via double bonds. It has a tetrahedral geometry around the sulphur atom.
Thiosulphuric Acid (H S O ): The structure is similar to sulphuric acid, but one of the doubly-bonded oxygen atoms is replaced by a sulphur atom.