NEET Practice Questions (MCQs) with Answers & Solutions

Potassium permanganate ($KMnO_4$) is used as a germicide due to its strong oxidizing properties. It can kill bacteria and fungi by oxidizing their cellular components, making it an effective disinfectant.

The general symbol 'Ln' is used to represent Lanthanoides. Lanthanoides are a series of 15 metallic elements from lanthanum (La) to lutetium (Lu) in the periodic table, and the symbol 'Ln' is used as a shorthand for this group.

The electronic configuration of Cerium (Ce) with atomic number 58 is $ [Xe] 4f^1 5d^1 6s^2 $. This configuration accounts for the distribution of electrons in the respective orbitals following the Aufbau principle.

The general electronic configuration of Lanthanoides is $ [Xe] 4f^{1-14} 5d^{0-1} 6s^2 $. This configuration covers the range of electrons that can be accommodated in the 4f, 5d, and 6s orbitals for Lanthanoides.

The hydroxides of lanthanides are more basic than $Al(OH)_3$ but less basic than $Ca(OH)_2$. This is because, as we move from left to right in the periodic table, the basicity of hydroxides decreases. Lanthanides are positioned between calcium and aluminum in terms of basicity.

Lanthanoides are separated based on their difference in basicity. The difference in basicity arises due to the lanthanide contraction, where the atomic and ionic sizes of lanthanides decrease with increasing atomic number, affecting their chemical behavior.

Lanthanoides generally form stable oxides with the formula $Ln_2O_3$. This is the most common oxide form for lanthanides, where 'Ln' represents any lanthanide element.

Pyrophoric Misch metal is often used in gas lighters due to its ability to produce sparks when struck. This property makes it ideal for igniting gas.

Ceric compounds, specifically ceric ammonium nitrate, are commonly used as oxidizing agents in volumetric analysis. They are utilized because of their ability to accept electrons and facilitate redox reactions.