Observations for electrochemistry

Question 1

What does Br give you

what does Cl2 give you

what does I2 give you

what does O2/H2 give you

Answer 1

brown gas

greenish yellow color w smell

brown liquid

O2 = colourless gas bubbles and relighting glowing splint

H2 = flaming splint pops and colourless gas bubble

Question 2

conditions of SHE

Answer 2

all gasses must be at pressure 100 kpa/1atm
298K in temp (25 C)
all solution concentration must be 1mol in dm^-3
all substances must be pure

Question 3

The standard electrode potential is?

Answer 3

The standard electrode potential is the
voltage obtained for a half-cell when it
is connected to the standard hydrogen
electrode. This measurement must be
conducted under standard conditions of
298 K with 1 mol dm−3 solutions and an
H2
(g) pressure of 100 kPa.

Question 4

salt bridge purpose?

Answer 4

The salt bridge is required to complete
the electrical circuit and to allow the
movement of ions into the half-cells to
maintain the balance of charges as ions
are formed

Question 5

differences between electrolytic and voltaic

Answer 5

A voltaic cell involves a spontaneous
reaction and converts chemical energy to
electrical energy whereas an electrolytic
cell involves a non-spontaneous reaction
with electrical energy being converted to
chemical energy.
In a voltaic cell the cathode is negative
and the anode is positive whereas in an
electrolytic cell the anode is negative and
the cathode is positive. (In both types of cell
oxidation occurs at the anode and reduction
at the cathode.)
A voltaic cell requires two separate
solutions joined by a salt bridge whereas an
electrolytic cell involves a single solution and
does not require a salt bridge.

Question 6

explain conditions of electroplating of silver

Answer 6

For the electroplating of silver, the anode has to be a silver bar or rod as this is where oxidation occurs and silver ions are
generated: Ag(s) → Ag+(aq) + e–
.
The cathode has to be the object that the
silver is being electroplated onto as this is
where reduction and the formation of solid
silver occurs: Ag+(aq) + e– → Ag(s).
The electrolyte needs to be a silver salt
solution, e.g. aqueous silver nitrate,
AgNO3
(aq), to ensure that only Ag+ ions are
present and reduction cannot involve other
metal ions.

Question 7

The most reactive metals are the strongest reducing agents. Explain why this statement is true

Answer 7

the stringest metals such as mg are the the strongest reducing agent because it wants to lose electrons the most of the rest.

Question 8

Three factors affecting the amount of metal discharged or deposited during electroplating

Answer 8

current
time
charge on ion