Ox/Red Basics
Define oxidation in terms of electrons transfer
Loss of electrons
O in H2O
-2
What is reduction? in terms of electron transfer
Gain of electrons
Where does oxidation occur?
Anode
What happens to plated objects?
gains metal
Define reduction in terms of oxygen transfer
Lose of oxygen
H in HCl?
+1
Write oxidation equation of Mg
Mg -> Mg2+ +2e-
Where does reduction occur?
Cathode
Mass change at cathode? increase or decrease?
mass increases
What is the reducing agent?
Substance that is oxidized
S SO2
+4
Write reduction reaction of Cu2+
Cu2+ +2e- -> Cu
Electron flow direction?
Anode to cathode
Oxidation or reduction at object?
reduction
What must change in all redox reactions?
Oxidation number changes
N in NH3?
-3
Which part of this reaction is the reduction reaction?
2Fe3+(aq) + 2I⁻(aq) → 2Fe2+(aq) + I2(aq)
2Fe3+(aq) → 2Fe2+(aq)
Why do metals conduct electricity when solid?
Because they contain mobile electrons.
What happens at anode?
oxidation
In this reaction: Fe2O3(s) + Al(s) --> Fe(s) + Al2O3(s)
Which one is the reducing agent (RA) and oxidizing agent (OA).
RA: Al
OA: Fe2O3
Cl in Cl2?
0
In a fuel cell, hydrogen reacts at one electrode:
___H2 → ___H+ + ___e⁻
Balance this half-reaction.
H2 → 2H+ + 2e⁻
Which non-metal conducts electricity? Sulfur, diamond, graphite, or iodine?
Graphite
Explain electroplating process briefly.
Metal ions reduced onto object