Electrochemistry

Diastereoisomers: Diastereoisomers are stereoisomers that are not mirror images of each other and differ in the arrangement of ligands in space.

Explanation:In coordination compounds, diastereoisomerism occurs due to different spatial arrangements of ligands around the central metal ion without being mirror images.

For the complex [Co(NH₃)₄Cl₂]⁺:

- When the two Cl ligands are adjacent, the complex is **cis-isomer**. - When the two Cl ligands are opposite to each other, it is the **trans-isomer**.

Structures:
Cis-isomer: Cl–Co–Cl angle = 90°
Trans-isomer: Cl–Co–Cl angle = 180°

Both are diastereoisomers of each other.

A reference electrode is an electrode that has a known and constant electrode potential and is used to measure the potential of other electrodes.
Explanation: Reference electrodes provide a stable potential against which the potential of the working electrode can be compared.

Examples include:

• Standard Hydrogen Electrode (SHE): E° = 0.00 V
• Calomel Electrode (Hg/Hg₂Cl₂ in KCl)
• Silver–Silver Chloride Electrode (Ag/AgCl)

The bleaching action of ozone is called dry bleach because it does not require the presence of moisture or water for bleaching.
Explanation: Ozone bleaches substances by oxidation, not by reduction or hydrolysis. It oxidizes colored substances to colorless products in the absence of water.

In contrast, bleaching agents like chlorine require moisture (forming HOCl) for bleaching, hence called wet bleach.

Reaction: The nascent oxygen oxidizes the colored material to a colorless form.

Answer:

Na₃AlF₆ (Sodium hexafluoroaluminate)

Explanation:

Cryolite is a double fluoride of sodium and aluminium, having the chemical formula Na₃AlF₆.

It is used as a solvent for alumina (Al₂O₃) in the Hall–Héroult process for the extraction of aluminium, as it lowers the melting point and increases conductivity of the electrolyte.

Definition of Electrochemical Series:
The electrochemical series is a list of standard electrode potentials of elements arranged in order of increasing or decreasing ability to lose or gain electrons.
Applications of the Electrochemical Series:

1. Predicting Redox Reactions
   • A species with a lower reduction potential acts as a reducing agent.
   • A species with a higher reduction potential acts as an oxidizing agent.
2. Determining Electrochemical Cell Feasibility
   • A spontaneous reaction occurs when is positive.

Apply Faraday’s first law of electrolysis, which is expressed as: Definitions:
- = mass of the deposit (2.4 g),
- = electric current (2.03 A),
- = Faraday’s constant (96500 C/mol),
- = electrochemical equivalent, calculated as (for Cu, , ).
First, calculate the electrochemical equivalent for copper: To find the time required for the deposition: Plugging in the known values:
Therefore, approximately 3593.34 seconds are needed to deposit 2.4 g of copper.

The standard international (SI) unit for molar conductivity, , is expressed as: In this expression:
- (Siemens) denotes the unit of electrical conductivity,
- indicates the area over which the conductivity is measured,
- signifies per mole of the solution's electrolyte.