Preskoči na glavni sadržaj
Prijava
Sign up for FREE
arrow_back
Biblioteka

GCSE revision (WW)

star
star
star
star
star
Posljednje ažuriranje about 1 month ago
4 questions
4
1
Pitanje 2
2.

Write balanced, ionic equations to show the electrode reactions which occur when copper is purified.

At the anode (where takes place) (Impure copper)

Cu → Cu²⁺ + 2e⁻

At the cathode (Where takes place) (pure copper)

Cu²⁺ + 2e⁻ → Cu

https://www.focuselearning.co.uk/s/1jstzoplah30 Focus education simulation.

Drugi mogući odgovor:
reduction
oxidation
6
5
Pitanje 1
1.

Electrolysis plays an important part in extracting some metals from their ores and in purifying others.

a) Define what is meant by the term electrolysis.

Electrolysis is of a substance using a electric current

b) Name one metal which is obtained from its ore by electrolysis.

Any metal that is carbon in the reactivity series.

For instance

https://www.focuselearning.co.uk/s/4cre8k45a2ix Simulation to predict the products of electrolysis.

Drugi mogući odgovor:
Gold
below
Silver
direct
decomposition
above
aluminium
Pitanje 3
3.

The particles that are responsible for the conductivity of electricity in metals are the (delocalsied)

The particles that are responsible for the conductivity of electricity in or aqueous ionic compounds are

The electrolysis of dilute sulphuric acid using inert electrodes produces two gases as products.

At the cathode

2H⁺ + 2e⁻ → H₂

At the anode

4OH⁻ → 2H₂O + O₂

Name a material which could be used as the inert electrodes in this experiment.

Drugi mogući odgovor:
electrons
oxidation
reduction
ions
solid
molten
Graphite
Pitanje 4
4.

The term is used to describe a reaction which gives out heat is .

When drops of water are added to anhydrous copper sulphate heat is given out and the solid turns

The anhydrous copper sulphate can be heated to remove the water of hydration so this reaction is an example of a reaction. https://www.focuselearning.co.uk/s/4wyjvlrqy7sj

The forward and reverse reactions are not, however, both occurring at the same rate so this is not an example of equilibrium. https://www.focuselearning.co.uk/s/40aaubdwqxw0

Drugi mogući odgovor:
dynamic
blue
reversible
Exothermic