Redox, electrochemistry, transition elements, Hydrogen-oxygen fuel cells Flashcards

1
Q

Give three different properties of transition metals which are not typical of other metals

A

(good) catalysts;
variable oxidation numbers;
form coloured compounds / coloured ions

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2
Q

Transition metal physical properties

A

They are lustrous
They are hard and strong
They conduct heat and electricity

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3
Q

Electrons are supplied

A

From battery / power supply / cell; [1 mark]
From negative electrode of battery to external circuit
OR
From iodide ion losing electron
OR
Oxidation of anion; [1 mark]

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4
Q

Examples of inert electrode

A

graphite or platinum

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5
Q

At which electrode does oxidation occur? Explain your choice.

A

anode/negative electrode and electrons lost(by hydrogen/H/H2)/electrons
move from this electrode

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6
Q

OH- equation

A

1) 4OH -> O2 + H2O + 4e-
2) OH- into oxygen and water

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7
Q

Molten potassium bromide give the products of electrolysis

A

Anode = Bromide
Cathode = Potassium

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8
Q

Define electrolysis

A

Breaking down of an ionic compound when molten or in aqueous solution Using electricity

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9
Q

Define oxidation in terms of electron transfer

A

Electron loss

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10
Q

What is the role of cryolite in aluminium extraction?

A

Lowers the melting point of electrolyte
Acts as a solvent to improve conductivity

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