Welcome to the Quiz!

This quiz contains 13 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-

Fe2+

Fe3+

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Zinc is a powerful agent in the reaction with dichromate(VI) ions, Cr2O72-.

reducing

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What chromium species is produced in the reaction between warm alkaline hydrogen peroxide and chromium(III) ions?

Cr2O72-

CrO42-

Cr3+

Cr2O3

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Which reaction is a disproportionation reaction?

Cu2O + H2SO4 ➔ Cu + H2O + CuSO4

2Fe3+ + 2I- ➔ 2Fe2+ + I2

2FeCl3 + Fe ➔ FeCl2

2Cu2+ + 4I- ➔ CuI + I2

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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?

ions with higher, more positive E⦵ values are more easily oxidised

ions with higher, more positive E⦵ values are more easily reduced

E⦵ values are not affected by ligands or pH

more alkaline solutions give higher, more positive redox potentials

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What is the colour change observed during a titration of MnO4- with a reducing agent such as Fe2+?

colourless to purple

purple to colourless

blue-black to colourless

colourless to blue-black

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Transition metals have variable oxidation states due to the similar of the outer d orbital electrons.

energies

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In general, more solutions give higher, more positive redox potentials.

acidic

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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 blue-black

colourless to purple

blue-black to colourless

purple to colourless

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When Cu2+ ions react with excess I- ions, what is the formula of the white precipitate formed?

Cu2I

CuI

CuI2

Cu2I2

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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

Cu2+ + I2 ➔ CuI + 2I-

2Cu2+ + I2 ➔ 2CuI + 2I-

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