U1-1-3 - Redox Titrations Flashcards
Part of the Oxidising and Reducing Agents topic from Unit 1 of Higher Chemistry, Chemical Changes and Structure
Standard solution
A solution of accurately known concentration
Procedure for preparing a standard solution:
* ________________________________
* add to volumetric flask with rinsings
* fill up to mark with water.
Procedure for preparing a standard solution:
* dissolve solid in small volume of water
* add to volumetric flask with rinsings
* fill up to mark with water.
Procedure for preparing a standard solution:
* dissolve solid in small volume of water
* ____________________________________
* fill up to mark with water.
Procedure for preparing a standard solution:
* dissolve solid in small volume of water
* add to volumetric flask with rinsings
* fill up to mark with water.
Procedure for preparing a standard solution:
* dissolve solid in small volume of water
* add to volumetric flask with rinsings
* __________________________.
Procedure for preparing a standard solution:
* dissolve solid in small volume of water
* add to volumetric flask with rinsings
* fill up to mark with water.
Self-indicating reaction
A reaction involving a reactant which changes colour to show the endpoint.
If permanganate is used as a titrant, what is the colour change seen during the titration (as the endpoint is reached)?
Colourless to purple
(permanaganate ions are purple, but before the endpoint they will keep getting converted into colourless Mn2+ ions)
Concordant titres
Titres within 0.2 cm3 of each other
(e.g. 17.2 and 17.4 are concordant)
Where do n1 and n2 come from?
Balanced equation - NOT calculated using n=cV!
E.g. in the equation shown, n1 (Fe2+) = 6, n2 (Cr2O72-) = 1
Suggest an improvement
Read burette at eye level
Use a white tile
Remove funnel from burette
Suggest what you would use to accurately measure 10 cm3 of solution
Pipette
Procedure to prepare a burette for titration:
* ____________________________
* remove filter funnel
* open tap to release air bubbles
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to release air bubbles
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove ____________
* open tap to release air bubbles
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to release air bubbles
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to ____________________
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to release air bubbles
* read scale from bottom of meniscus.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to release air bubbles
* read scale from _______________________.
Procedure to prepare a burette for titration:
* rinse with solution which will be added to the burette (NOT water)
* remove filter funnel
* open tap to release air bubbles
* read scale from bottom of meniscus.
What indicator should be used in a titration involving iodine?
Starch
turns blue-black in the presence of iodine