Existence of ions

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Existence of ions(?????)
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Electrolysis (??) of molten (??) lead(II) bromide
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Integrated Chemistry Today

• Book 1A, 2nd Edition6.3 How does a molten
  electrolyte conduct electricity(pg 74-76)

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Electrolysis of molten lead(II) bromide
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? In the electrolysis experiment, when does
lead(II) bromide conduct ?
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? In the electrolysis experiment, when does
lead(II) bromide conduct ?

• Lead(II) bromide only conducts when it is heated
  to molten (??).

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Electrolysis of molten lead(II) bromide
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? What happens at the positive electrode in the
electrolyte of molten lead(II) bromide ?
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? What happens at the positive electrode in the
electrolyte of molten lead(II) bromide ?

• A brown fume (?) evolves (??) from the positive
  electrode.

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Electrolysis of molten (?) lead(II) bromide
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Electrolysis of molten (?) lead(II) bromide
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? Why is the apparatus (??) usually connected to
the fume cupboard (??) ?
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Electrolysis of molten (?) lead(II) bromide
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? Why is the apparatus (??) usually connected to
the fume cupboard (??) ?
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? Why is the apparatus (??) usually connected to
the fume cupboard (??) ?

• Because toxic vapour (??) of bromine is produced
  in the electrolysis, this is to prevent (??) the
  toxic vapour from escaping (??) to the laboratory.

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? Why is lead(II) bromide not conductive in solid
state but conductive in molten (??) state?
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? Why is lead(II) bromide not conductive in solid
state but conductive in molten (??) state?

• In solid state, the charged particles (ions)
  inside lead(II) bromide are not movable / mobile
  (????), therefore, it cannot conduct.
• In molten state (liquid state), the ions become
  mobile and lead(II) bromide becomes conductive.

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Classwork (pg 72)

• 1. Copper(II) chloride conducts electricity in
  aqueous solution , but not in solid state.
  Explain why.

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Classwork (pg 72)

• 1. Copper(II) chloride conducts electricity in
  aqueous solution , but not in solid state.
  Explain why.
• In solid states, the positive ions and the
  negative ions are attracted to each other by
  strong electrostatic forces and not free to move.
  i.e. cannot conducts. In aqueous state, the ions
  are movable, thus it can conduct electricity.

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Classwork (pg 72)

• 2. Consider that we pass electricity through an
  aqueous solution of copper(II) chloride.
• a) Draw a dagram to show the movement of ions.
• b) What product is formed at the negative
  electrode ? Explain how the product is formed.
• c) What product is formed at the positive
  electrode ? Explain how the product is formed.

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Classwork (pg 72)

• a) Draw a dagram to show the movement of ions.

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Classwork (pg 72)

• a) Draw a dagram to show the movement of ions.

?
?
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Classwork (pg 72)

• b) What product is formed at the negative
  electrode ? Explain how the product is formed.

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Classwork (pg 72)

• b) What product is formed at the negative
  electrode ? Explain how the product is formed.
• Copper metal. Positive copper(II) ions are
  attracted towards the negative electrode and
  discharge to form copper metal.

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Classwork (pg 72)

• c) What product is formed at the positive
  electrode ? Explain how the product is formed.

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Classwork (pg 72)

• c) What product is formed at the positive
  electrode ? Explain how the product is formed.
• Chloride gas. Negative chloride ions are
  attracted towards the positive electrode and
  discharge to form chlorine gas.

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Integrated Chemistry Today

• Short Question Exercise (pg 97 )Q 4

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Q 4 (pg 97)
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Q 4 (pg 97)
in aqueous state mobile ions in molten state
free ions
Sodium chloride
Lead(II) bromide in molten state free ions