Volumetric Analysis Flashcards
It is a general term for a method in quantitative chemical analysis in which the amount of a substance is determined by the measurement of the volume that the substance occupies
Volumetric analysis
It is commonly used to determine the unknown concentration of known reactant.
Volumetric analysis
often referred to as titration
Volumetric analysis
a laboratory technique in which one substance of known concentration and volume is used to react with another substance of unknown concentration
Titration
Involves the preparations, storage, and measurement of the volume of chemicals for analysis.
Volumetric analysis
Quantitative chemical analysis which determines volume of a solution of accurately known concentration required to react quantitatively with the analyte (whose concentration to be determined).
Volumetric titrimetry
The volume of titrant required to just completely react with the analyte is the _____
titre
A process in which a standard reagent is added to a solution of analyte until the reaction between the two is judged complete.
Titration
it is the known solution placed in the burette
Titrant
The unknown solution placed in the Erlenmeyer flask
Analyte
Where is the analyte placed?
Erlenmeyer flask
Where is the titrant placed?
Burette
A reagent solution of accurately known concentration
- Standard solution
- Primary standard
A process to determine the concentration of a solution of known concentration by titrating with a primary standard.
Standardization
The point at which the reaction is observed to be completed
End point
Serves as a signal that tells the analyst to stop adding reagent and make the final reading of on the burette
End point
What is the end point referred to?
Signal
The point at which an equivalent or stoichiometric amount of titrant is added to the analyte based on the stoichiometric equation.
Equivalent point
What are the equipment used in Volumetric analysis or titration?
- Pipette
- burette
- conical flask
- wash bottles
- funnel
- volumetric flasks
For measuring accurate and precise volumes of solutions.
pipette
For mixing two solutions.
conical flask
For pouring measured volumes of solutions.
burette
These contain distilled water for cleaning equipment.
wash bottles
For transfer of liquid without spilling.
funnel
A flask used to make up accurate volumes for solutions of known concentration.
volumetric flasks
requirements for successful volumetric titration
- Reaction must be stoichiometric, well defined reaction between titrant and analyte.
- Reaction should be rapid.
- Reaction should have no side reaction, no interference from other foreign substances.
- Must have some indication of end of reaction, such as color change, sudden increase in pH, zero conductivity, etc.
- Known relationship between endpoint and equivalence point.
requirements for successful volumetric titration
- Reaction must be stoichiometric, well defined reaction between titrant and analyte.
- Reaction should be rapid.
- Reaction should have no side reaction, no interference from other foreign substances.
- Must have some indication of end of reaction, such as color change, sudden increase in pH, zero conductivity, etc.
- Known relationship between endpoint and equivalence point.
Is a general term expressing the amount of solute contained in a given material. Expressed by different ways.
Concentration
The number of moles of solute divided by the number of liters of solution containing the solute (is gram molecular weight dissolved in one liter solution).
Molarity
Defined as number of equivalents of solute divided by the number of liters of solution containing the solute (gm equivalent weight dissolved in one liter of solution).
Normality
Is defined as part by wt of substance which is chemically equivalent to one part by wt of hydrogen or 8 part by wt of oxygen or 35*5 part by wt of chlorine.
Equivalent weight
It depends on reaction in which it takes place.
equivalent weight
The branch of chemistry which deals with weight relation between reactant and product is called stoichiometry.
stoichiometry
- A solution whose concentration is accurately known.
- Prepared by dissolving an accurately wt quantity of highly pure material called primary standard and diluted to an accurately volume in volumetric flask.
- Otherwise a solution of approximately desired concentration is titrated against the primary standard solution and concentration is determined, this is called standardization.
Standard solution
- Measurements are made with reference to standards.
- The accuracy of a result is only as good as the quality and accuracy of the standards used.
- A standard is a reference material whose purity and composition are well known and well defined.
Primary standard
Primary Standards - Used as titrants or used to standardize titrants
Eg. Acid base titration Na2CO3, KHP, Succinic acid, Benzoic acid, Oxalic acid
Eg for redox titration: K2Cr2O7, Potassium bromate, KlO3, Socium Oxilate, arsionus trioxide
Eg for PPT titrations: NaCl, KCl, KBr, Silver nitrate
Eg for Complometric titration: Pure metals like Zn, Mg, Mn, and its salts
Cheaprst kind, have not been purified well and cant be used for quantitative work
Technical or commercial grade
