Do you remember??What the meanings are of the following:•Pipette•Aliquot•Burette•Titre•Titration/ conical flask•Concordant results

Volumetric Analysis

• This is a quantitative analysis that uses precise volumes of solutions in order to determine the unknown concentration of a solution.

The easiest method is titrations however they can be altered such as pH curves, analysis for % by mass and concentration of a solute in a solution

New terms and meanings!!

• End point: the point at which we can detect the reaction is complete.

• Equivalence point: the point where the reaction is almost complete, the reactants are in their exact mole proportions in accordance with the equation for that specific reaction.

• Find the meanings for the following:• Primary standard• Secondary standard• Volumetric flask• Standard flask • Deliquescent

Titration techniques

• Virtual tutorial/quiz• http://

group.chem.iastate.edu/Greenbowe/sections/projectfolder/animationsindex.htm

Primary standards

• Conditions to acknowledge:• The reaction must be spontaneous, fast and able to

go to completion.• The end point needs to be clearly defined.• The reaction between a weak acid and a weak base

does not go to completion and does not have a defined end point. This means that if we wish to analyse a solution of a weak acid, for example, we must react it with a strong base, not a weak base.

Primary Standards

• A substance that can be accurately weighed out to provide a solution of known

• composition and concentration, and which therefore can be used directly to

• standardise another substance, is called a primary standard.

• Strong acids and bases cannot be used as primary standards.

Primary Standards

• What is suitable:• is obtainable in very pure form• has a known formula (including a known degree of

hydration)• does not absorb or react with any moisture or other

chemicals from the air• does not decompose or lose water of hydration on storage

or when exposed to air• has a reasonably high molar mass• is completely soluble in water at room temperature• is readily available and relatively inexpensive.

Secondary Standards

• Hence, we can only know the approximate concentration of a strong acid/base in a solution.

• Strong acids and strong bases therefore must always first be standardised before they are used to determine the concentration of any other substance. As a result, we call these Secondary standards.

Secondary Standards

• Table 2.6 shows standards commonly used for analysis.

• Question time!!! We love questions!!!