Titration Definitions Flashcards
Primary Standard
A solution of known concentration that is readily available, pure, stable, high molar mass.
Secondary Standard
A solution whose concentration has been determined using primary standards.
Solute
A substance dissolved in the solvent
Anhydrous
A substance containing no water
Hygroscopic
A substance that has the ability to absorb moisture from the surrounding environment.
Deliquescence
The process by which a solid substance absorbs moisture from the air and turns it into a liquid.
Analyte
The solution of unknown concentration that will be analysed in titration.
Titrant
The solution in a burette. A solution of known concentration that is added to another solution to determine its concentration.
Titre
The strength of a solution or concentration of a substance in solution as determined by titration.
Aliquot
A specifically measured portion of sample.
Why is NaOH a bad primary standard?
Hygroscopic meaning it absorbs water from atmosphere and reacts with carbon dioxide from the atmosphere.
Why is HCl a bad primary standard?
HCl fumes and loses HCl gas
Why is H2SO4 a bad primary standard?
Hygroscopic meaning it absorbs water from the atmosphere.
Why do volumetric flasks have a narrow neck?
To minimise surface area where liquid is to be measured.
What is the purpose of pipette fillers?
To quickly and safely deliver solution from a pipette.
What is a titration?
A laboratory based procedure in which a solution of known concentration is used to determine the concentration of an unknown solution.
Endpoint
A point in a titration that signifies its completion by a change in the colour or intensity of the solution
Equivalence point
The point where the amount of titrant added is just enough to completely neutralise the analyte solution. The moles of standard solution equal the moles of the unknown.
Volumetric Flask Function
- To measure and prepare solutions with high precision
- To prepare standard solutions
- Its calibration allows for accurate volume measurements with minimal uncertainty
Pipette Function
Used to measure or transfer small quantities of liquids
Burette Function
Used to measure and dispense liquids or gases (aliquots)
Allows the titrant to be added to the analyte slowly overtime
Conical Flask Function
Used to hold, mix and heat liquids particularly when swirling or swirling motions are needed during a chemical reaction
Phenolphthalein
8.3-10, Colourless to Fuchsia, Weak Acid + Strong Base
Bromothymol blue
6-7.6, Yellow to Blue, Strong Acid + Strong Base
