NEET Practice Questions (MCQs) with Answers & Solutions

The magnetic moment can be calculated using the same formula: $$ ext{Magnetic Moment} ( ext{BM}) = ext{n(n+2)} $$, where 'n' is the number of unpaired electrons. For $Fe^{2+}$ in $FeSO_4$, which has an electron configuration of [Ar] 3d^6, there are 4 unpaired electrons. Therefore, the magnetic moment is approximately 4.90 BM.

Transition metal ions are known to form complex compounds due to their small size, high nuclear charge, and the presence of different oxidation states. However, the statement 'Co-ordination covalent bond is not directional' is incorrect. Co-ordination bonds are indeed directional, as the geometry of the complex depends on the spatial arrangement of the ligands around the central metal ion.

To prepare alloys, the difference in atomic radii of the constituent elements should be less than 15%. This rule helps ensure that the alloy has a homogeneous structure and maintains good mechanical properties. If the atomic radii difference is too large, it can lead to structural inconsistencies and weaken the alloy.

Bronze is an alloy that has been traditionally used for making coins. It is composed primarily of copper, usually with tin as the main additive. The properties of bronze, such as its hardness and resistance to corrosion, make it suitable for coinage.

Amalgam is an alloy that is commonly used in dentistry for filling cavities. It consists of mercury mixed with other metals such as silver, tin, and copper. Its durability and ease of manipulation make it ideal for dental repairs.

The reaction of iron chromite (FeCr2O4) with sodium carbonate (Na2CO3) and oxygen (O2) produces sodium chromate (Na2CrO4), iron(III) oxide (Fe2O3), and carbon dioxide (CO2). The balanced chemical equation is: $$ 4FeCr_2O_4 + 8Na_2CO_3 + 7O_2 ightarrow 8Na_2CrO_4 + 2Fe_2O_3 + 8CO_2 $$