Redox Titrations Flashcards

1
Q

Why are indicators not always needed for redox titrations?

A

Because one chemical is a transition metal which are coloured. A change in its colour or fading of the colour indicates the end point

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2
Q

What are the examples of redox tritrations you need to know?

A

Manganate (VII), Ethanedioate and dichromate (VI)

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3
Q

Describe the procedure of Manganate (VII) Tritration.

A
  1. Standard solution of KMnO4 added to burette
  2. Using a pipette, a measured volume of solution under analysis transferred to conical flask
  3. Excess dilute H2SO4 added to provide H+
  4. Trial titration carried out
  5. KMnO4 added from burette and oxidises solution under analysis (Fe2+ —> Fe3+
  6. MnO4- ions reduced to Mn2+ and lose purple colour (pale pink)
  7. Once all the chemical under analysis has been oxidised, next drop of KMnO4 remains purple after swirling. pale pink —> purple
  8. Record Titre
  9. Repeat titration until 2 concordant (withing 0.1cm3) results are achieved
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4
Q

What is the equation of redox tritration of permanganate and Fe2+?

A

MnO4- + 5Fe2+ + 8H+ —> 5Fe3+ + Mn 2+ + 4H2O

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