Pharma Flashcards
(21 cards)
What is the total mark distribution for the course Pharmaceutical Analytical Chemistry II (PHC 103)?
Midterm: 10 marks, Quiz & Attendance: 5 marks, Lab Attendance & Behavior: 5 marks, Practical Exam: 20 marks, Oral Exam: 10 marks, Written Final Exam: 50 marks
What does quantitative analysis deal with?
Determination of the quantity of the substance to be analyzed (concentration)
What are the classifications of quantitative analysis based on the quantity measured?
- Macro-analysis: 100 mg and more
- Semi-micro analysis: 10-100 mg
- Micro-analysis: not exceeding 1 mg
How is quantitative analysis classified according to the physical state of the substance?
Gas analysis, when the substance to be analyzed is available in gaseous state
What are the classifications of quantitative analysis according to the process of measurement?
- Volumetric analysis
- Gravimetric analysis
- Instrumental methods of analysis
What is volumetric analysis?
It depends on measuring the volume of the analyzed sample and the volume of standard solution used for complete reaction
What does gravimetric analysis depend on?
Weighing the final product of reaction after its isolation in pure and stable form of definite chemical structure
List the requirements of titrimetric reactions
- The reaction must be simple and expressed by a chemical equation
- A single reaction must occur between the sample and titrant
- The reaction must be instantaneous (rapid)
- Suitable standard solution must be available
- The end point should be easily detected
What is a quantitative reaction?
A reaction that proceeds forward to produce stable product(s) such as weakly ionizable compounds
What is a neutralization reaction?
A reaction in which an acid reacts with a base to form slightly ionized water
Define standard solutions
Solutions of exact, known concentration, classified into molar, normal and empirical solutions
What is a molar solution (M)?
A solution of known concentration, each liter contains the gram molecular weight or its fractions or multiples
What is a normal solution (N)?
A solution of known concentration, each liter contains the gram equivalent weight or its fractions or multiples
How is equivalent weight calculated for acids?
Eq.wt = (M.wt) / number of replaceable hydrogen
What is an empirical solution?
A solution of known concentration, prepared so that 1ml reacts with a definite amount of the analyzed substance
What are primary standard chemicals?
- Easily available in high purity
- Easily tested for impurity
- Stable
- React quantitatively according to a balanced chemical equation
- Readily soluble in solvent
- High equivalent weight
What are secondary standard chemicals?
Substances used for standardization whose content has been found by comparison against primary standard
What is the direct method for the preparation of standard solutions?
An accurately weighed amount of the solute is transferred into a volumetric flask, dissolved in the solvent, and completed to the required volume
What does the standardization factor (f) represent?
f = volume of exact standard / volume of approximate standard
How is the concentration of sample solutions calculated in gm/L?
Concentration = (Volume of exact standard consumed x f x Equivalent factor (F) x 1000) / Volume of the Sample
Fill in the blank: A _______ solution is a solution of known concentration, prepared in such a way that 1ml of it reacts with a definite amount of the analyzed substance.
[empirical]
