Pharma Important Definitions
Normality is a measure of concentration equal to gram equivalent weight per litre of solution. Gram equivalent weight is the measure of the reactive capacity of a molecule.Normality also known as equivalent of a solution.
Molarity is the concentration of a solution expressed as the number of moles of solute per litre of solution.
Mole fraction is a unit of concentration. It is defined to be equal to number of moles of a component divided by the total number of moles of a solution.
pH, pH Range and pH Scale
pH is a measure of the hydrogen ion concentration of a solution. Solution with high concentration of H+ ions have a low pH. Solution with low concentration of H+ ions have high pH. pH scale is measure of acidity or alkalinity of water soluble substances. pH stands for potential of hydrogen.
Buffer is a solution containing either a weak acid and its salts or a weak base and its its salt which is resistant to changes in pH. or
Buffer is an aqueous solution of either a weak acid and its conjugate base or weak base and its conjugate acid.
Buffers are used to maintain a stable pH in a solution, as they can neutralize small quantities of additional acid or base. buffers are also called hydrogen ion buffer.
Dissolution is a process in which a solid substances solubilizes in a given solvent. mass transfer from the solid surface to the liquid phase.
Disintegration time is the time required for a dosage form to breakup into granules of specified size or smaller under carefully specified condition.
A solution is a homogeneous mixture of one or more solutes dissolved in a solvents.
Solute + solvent = Solution
A meniscus is the curvature of the surface of the water.
- Concave meniscus – colorless solution – lower meniscus
- Convex meniscus – Colored solution – Upper meniscus
Ultarsonication is the process of Dispersing, Disrupting or inactivating biological materials, removal of air bubbles in solution by use of sound wave energy.
Glass wares in Laboratory
There are different materials used in making laboratory glasses such as
- Borosilicate glasses
- Quartz glasses
- Soda lime glasses
- Actinic glasses
Class A glassware: for Accuracy (most accurate)
Class B glassware; Accuracy when not required or critical
Filtration is a technique used to separate solids from liquids, in the act of pouring a mixture into a membrane (filter paper) that allows the passage of liquid (the filtrate) and results in the collection of solids.
Two filtration techniques
- Gravity filtration
- Vaccum filtration