Back titration Depth Study

Year 11

titration

a laboratory technique used to determine the concentration of an unknown substance (analyte) by reacting it with a solution of known concentration (titrant) until the reaction is complete

OR

Titrations are a form of volumetric analysis whereby precise volume-measuring equipment is used – volumetric flasks, burettes and volumetric pipettes – in order to determine the concentration of a substance via a chemical reaction (NOTIFICATION INFO)

• will be used to determine the number of moles of hydrogen ions that a single Quick-Eze tablet can neutralise

back titration

a known excess of a standard solution (the "reagent") is added to an unknown solution (the "analyte") → working backwards to find analyte (that’s why it's called a back titration??)

OR

By knowing the exact number of moles of acid that were added initially, and calculating the exact number of moles left over, the number of moles of acid which reacted with carbonate in the antacid tablet can be determined (NOTIFICATION INFO)

titre

the concentration of a solution as determined by titration

• the titre is the measured volume of the titrant, while the titrant is the solution used in the process

titrant

the "known" solution which has a precise and accurate concentration in a titration

aliquot

Small sample of a larger solution - a representative subsample of a larger sample. In titrations, sn _____ of the analyte solution is transferred to a flask for the titration

endpoint

the point where a visual indicator (like a color change) signals that the reaction between the titrant and the analyte is complete

equivalence point

the point at which enough titrant has been added in the the correct stoichiometry ratio to the analyte, so as to reach full neutralisation

neutralisation reaction

titration reaction

Acid + Base >>> Salt + Water

indicator

changes color to signal the endpoint of the reaction, indicating when the reaction between the titrant and analyte is complete

e.g. we used Phenolphthalein