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This quiz contains 6 questions from a mix of 1 subtopics.
What is the purpose of adding starch indicator towards the end of an iodine-thiosulfate titration?
to slow down the reaction between iodine and thiosulfate
to prevent the formation of unwanted byproducts
to enhance the visibility of the end point
to speed up the reaction between iodine and thiosulfate
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In an iodine-thiosulfate titration, agents such as Cu2+ and ClO- react with an excess of iodide ions to produce iodine. This solution is titrated with a sodium thiosulfate solution. A colour forms when starch indicator is added. When the end point is reached, all of the has just reacted and the colour fades.
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Manganate(VII) titrations can be used for the analysis of many different agents such as Fe2+ ions and (COOH)2.
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What is the colour change at the end point of an iron-manganate(VII) titration?
black to colourless
colourless to black
colourless to purple
purple to colourless
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What is the overall balanced equation for the reaction between manganate(VII) ions and iron(II) ions?
MnO4- + 8H+ + 5Fe3+ ➔ Mn2+ + 4H2O + 5Fe2+
MnO4- + 8H+ + Fe3+ ➔ Mn2+ + 4H2O + Fe2+
MnO4- + 8H+ + Fe2+ ➔ Mn2+ + 4H2O + Fe3+
MnO4- + 8H+ + 5Fe2+ ➔ Mn2+ + 4H2O + 5Fe3+
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Calculate the mean titre, in cm3, of the following titration results.
Give your answer to 3 decimal places.
cm3
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