The f- and d- block elements - Oxidation Property of Dichromate
- Introduction to the oxidation property of dichromate
- Role of dichromate in redox reactions
- Overview of the f-block and d-block elements
What is Dichromate?
- Chemical formula: Cr2O7^2-
- Orange-red solid compound
- Contains chromium in the +6 oxidation state
Oxidation Property of Dichromate
- Dichromate ions are strong oxidizing agents
- Capable of transferring electrons to other substances
- Chromium undergoes reduction to a lower oxidation state
Half-Reaction of Dichromate
- The half-reaction for the reduction of dichromate:
- Cr2O7^2- + 14H+ + 6e- → 2Cr^3+ + 7H2O
Examples of Dichromate Reactions
- Oxidation of alcohols to aldehydes/ketones
- Oxidation of primary alcohols to carboxylic acids
- Conversion of aldehydes to carboxylic acids
- Reduction of dichromate by organic compounds
Example 1: Oxidation of Alcohols
- Alcohols can be oxidized to form aldehydes or ketones
- Dichromate acts as an oxidizing agent in this reaction
- Example: CH3CH2OH + [O] → CH3CHO
Example 2: Oxidation of Primary Alcohols
- Primary alcohols can be further oxidized to carboxylic acids
- Dichromate is reduced in this process
- Example: CH3CH2CH2OH + [O] → CH3CH2COOH
Example 3: Conversion of Aldehydes
- Aldehydes can be oxidized to carboxylic acids using dichromate
- Dichromate is often used in laboratory experiments for this purpose
- Example: CH3CHO + [O] → CH3COOH
Example 4: Reduction of Dichromate
- Organic compounds can reduce dichromate to lower oxidation states
- Example: C6H12O6 + [Cr2O7^2-] → 6CO2 + Cr^3+
Summary
- Dichromate ions are powerful oxidizing agents
- They can transfer electrons to other substances
- Various organic compounds can be oxidized using dichromate
- Examples include alcohols, aldehydes, and organic acids
The f- and d- block elements - Oxidation Property of Dichromate
- Introduction to the oxidation property of dichromate
- Role of dichromate in redox reactions
- Overview of the f-block and d-block elements
What is Dichromate?
- Chemical formula: Cr2O7^2-
- Orange-red solid compound
- Contains chromium in the +6 oxidation state
Oxidation Property of Dichromate
- Dichromate ions are strong oxidizing agents
- Capable of transferring electrons to other substances
- Chromium undergoes reduction to a lower oxidation state
Half-Reaction of Dichromate
- The half-reaction for the reduction of dichromate:
- Cr2O7^2- + 14H+ + 6e- → 2Cr^3+ + 7H2O
Examples of Dichromate Reactions
- Oxidation of alcohols to aldehydes/ketones
- Oxidation of primary alcohols to carboxylic acids
- Conversion of aldehydes to carboxylic acids
- Reduction of dichromate by organic compounds
Example 1: Oxidation of Alcohols
- Alcohols can be oxidized to form aldehydes or ketones
- Dichromate acts as an oxidizing agent in this reaction
- Example: CH3CH2OH + [O] → CH3CHO
Example 2: Oxidation of Primary Alcohols
- Primary alcohols can be further oxidized to carboxylic acids
- Dichromate is reduced in this process
- Example: CH3CH2CH2OH + [O] → CH3CH2COOH
Example 3: Conversion of Aldehydes
- Aldehydes can be oxidized to carboxylic acids using dichromate
- Dichromate is often used in laboratory experiments for this purpose
- Example: CH3CHO + [O] → CH3COOH
Example 4: Reduction of Dichromate
- Organic compounds can reduce dichromate to lower oxidation states
- Example: C6H12O6 + [Cr2O7^2-] → 6CO2 + Cr^3+
Summary
- Dichromate ions are powerful oxidizing agents
- They can transfer electrons to other substances
- Various organic compounds can be oxidized using dichromate
- Examples include alcohols, aldehydes, and organic acids
Advantages of Dichromate
- Rapid and efficient oxidation reactions
- High selectivity for specific functional groups
- Widely used in laboratory experiments
- Can be easily synthesized
- Stable at room temperature
Disadvantages of Dichromate
- Highly toxic and corrosive
- Environmentally hazardous
- Requires careful handling and disposal
- Alternatives to dichromate preferred in many applications
- Limited industrial use due to safety concerns
Environmental Impact
- Dichromate is a known carcinogen
- Can contaminate soil and water
- Long-term exposure can lead to health issues
- Regulations in place to control its use and disposal
- Minimization and recycling methods being explored
Alternatives to Dichromate
- Other oxidizing agents such as permanganate, peroxides, and hypochlorite
- Transition metal catalysts like palladium, platinum, and gold
- Organic and biological oxidants
- Research ongoing to develop safer and greener alternatives
- Balancing effectiveness and environmental impact is crucial
Industrial Uses of Dichromate
- Production of pigments (chrome yellow, chrome green)
- Surface treatment of metals (chrome plating)
- Manufacturing of catalysts
- Tanning industry for leather processing
- Preservation of wood and materials
Lab Safety Precautions for Dichromate
- Always wear gloves, goggles, and a lab coat
- Avoid inhalation or ingestion
- Work in a well-ventilated area or under a fume hood
- Handle with appropriate tools and equipment
- Properly label and store unused dichromate
Review Questions
- What is the oxidation state of chromium in dichromate?
- Name two common industrial uses of dichromate.
- How does dichromate act as an oxidizing agent?
- What are the advantages of using dichromate?
- Why is proper handling and disposal of dichromate important?
Answers to Review Questions
- The oxidation state of chromium in dichromate is +6.
- Two common industrial uses of dichromate are pigments and surface treatment.
- Dichromate acts as an oxidizing agent by transferring electrons to other substances.
- Advantages of dichromate include efficient oxidation reactions and high selectivity.
- Proper handling and disposal of dichromate are important to prevent environmental damage and health risks.
Summary
- Dichromate is a strong oxidizing agent.
- It can transfer electrons to various organic compounds.
- Examples include oxidation of alcohols, aldehydes, and primary alcohols to carboxylic acids.
- Dichromate has both advantages and disadvantages.
- Safety precautions and alternatives to dichromate are necessary.
The f- and d- block elements - Oxidation Property of Dichromate Introduction to the oxidation property of dichromate Role of dichromate in redox reactions Overview of the f-block and d-block elements