Pharmaceutical Chemistry: Principles, Tests, and Standards
Radiations and Radiopharmaceuticals
Properties of Alpha (α), Beta (β), and Gamma (γ) Radiations
- Alpha (α): Helium nuclei (+2 charge), high mass, low penetration, high ionization. Stopped by paper.
- Beta (β): High-speed electrons/positrons (±1 charge), small mass, moderate penetration/ionization. Stopped by aluminium.
- Gamma (γ): Electromagnetic waves (no mass/charge), speed of light, high penetration, low ionization. Stopped by lead/concrete.
Precautions for Radiopharmaceuticals
- Use protective gear
Principles of Electrochemistry and Chromatography
Oxidizing and Reducing Agents
Definitions
Oxidizing Agent: An oxidizing agent is a substance that accepts electrons and is reduced during a chemical reaction.
Reducing Agent: A reducing agent is a substance that donates electrons and is oxidized during a chemical reaction.
Example Reaction
Zn + CuSO4 → ZnSO4 + Cu
- Zn: Reducing Agent
- Cu2+: Oxidizing Agent
Note: There is no difference between Galvanic and Voltaic cells; both terms refer to the same electrochemical system.
Comparison of Electrochemical Cells
| Feature | Galvanic |
|---|
Scientific Study: Variables, Units, and Methodology
Scientific Study: Very Short Questions
- (2081 Koshi Q.No. 2a)
Dependent variable: Solubility of salt. - What is the dependent variable in throwing a stone with a stretched rubber band?
Answer: Distance travelled by the stone. - Write the fundamental units included in the unit of force.
Answer: Kilogram (kg), metre (m), and second (s). - Write a difference between fundamental unit and derived unit.
Answer: Fundamental units are independent, whereas derived units are formed from fundamental units. - Define controlled
Pharmaceutical Analysis: Principles and Titration Methods
Limit Test for Sulphate
The Limit Test for Sulphate is used to detect and control the amount of Sulphate Impurity present in pharmaceutical substances. It is based on the formation of Barium Sulphate, which produces Turbidity/Opalescence. The turbidity of the Test Solution is compared with that of the Standard Solution.
Principle
Sulphate Ions react with Barium Chloride to form Barium Sulphate, a white insoluble precipitate.
Reaction: SO₄²⁻ + BaCl₂ → BaSO₄ ↓ + 2Cl⁻
The Turbidity produced
Read MoreFundamental Principles of Chemical Thermodynamics
Importance of the Zeroth Law of Thermodynamics
(a) Importance of Zeroth Law of Thermodynamics: The Zeroth Law of Thermodynamics states that if two systems are separately in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
Why Heat Capacity Cp is Greater Than Cv
(b) Why is Cp greater than Cv? At constant volume, no work is done by the gas, so all the heat supplied increases its internal energy. At constant pressure, the gas expands and does external work
Read MoreOrganic Chemistry Principles and Reaction Mechanisms
Electrophilic Substitution Reaction
Answer: An electrophilic substitution reaction is a reaction in which an electrophile replaces a hydrogen atom in an aromatic compound.
Example: Nitration of benzene.
Nitration of Benzene
Answer: Nitration is the reaction in which a nitro group (NO2) is introduced into benzene.
It is carried out using concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4).
Product formed: Nitrobenzene.
Friedel-Crafts Alkylation Reaction
Answer: Friedel-Crafts alkylation
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