Welcome to the Quiz!
This quiz contains 10 questions from a mix of 1 subtopics.
Which ion is reduced in the redox reaction between iron(II) ions and manganate(VII) ions?
Mn2+
MnO4-
Fe3+
Fe2+
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Select the correct statement that describes the redox reaction that takes place when the two half-equations below are combined.
Fe3+(aq) + e- ⇌ Fe2+(aq) E⦵ = +0.77 V
MnO4-(aq) + 8H+(aq) + 5e- ⇌ Mn2+(aq) + 4H2O(l) E⦵ = +1.51 V
electrons are transferred from Fe2+ to MnO4-
electrons are transferred from Fe3+ to MnO4-
electrons are transferred from MnO4- to Fe2+
electrons are transferred from MnO4- to Fe3+
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Write the equation and calculate E⦵ for the feasible reaction that occurs when the following two half-equations are combined.
Fe3+(aq) + e- ⇌ Fe2+(aq) E⦵ = +0.77 V
MnO4-(aq) + 8H+(aq) + 5e- ⇌ Mn2+(aq) + 4H2O(l) E⦵ = +1.51 V
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Which of the following statements about redox potentials is true?
more alkaline solutions give higher, more positive redox potentials
ions with higher, more positive E⦵ values are more easily reduced
E⦵ values are not affected by ligands or pH
ions with higher, more positive E⦵ values are more easily oxidised
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What is the colour change observed during a titration of MnO4- with a reducing agent such as Fe2+?
purple to colourless
colourless to purple
colourless to blue-black
blue-black to colourless
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Transition metals have variable oxidation states due to the similar of the outer d orbital electrons.
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In general, more solutions give higher, more positive redox potentials.
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When Cu2+ ions react with excess I- ions, what is the formula of the white precipitate formed?
Cu2I2
Cu2I
CuI
CuI2
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What is the colour change observed at the endpoint of a copper(II) iodine/thiosulfate titration when using starch indicator?
colourless to purple
colourless to blue-black
purple to colourless
blue-black to colourless
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What is the overall balanced equation for the reaction between copper(II) ions and iodine in an iodine-thiosulfate titration?
2Cu2+ + 2I- ➔ CuI + I2
2Cu2+ + 4I- ➔ 2CuI + I2
2Cu2+ + I2 ➔ 2CuI + 2I-
Cu2+ + I2 ➔ CuI + 2I-
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