Unit 5: Electrochemistry

Question 0

The loss of the electrons is called….

Answer 0

Oxidation

BUT the reactant causing the oxidation to occur is called the reducing agent

Question 1

What are redox reactions?

Answer 1

Occurs when reactants transfer one or more electrons.

Question 2

Gaining electrons is called….

Answer 2

Reduction

BUT the reactant causing the reduction is called the oxidizing agent

Question 3

Half reactions are…

Answer 3

Reactions showing the oxidation or reduction happening separately including the lost or gained electrons.
* the total change on the left side equals the charge on the right side

Question 4

What is a disproportionation?

Answer 4

When 2 atoms of the same element redox each other
Ex.
O: Cu 1+ –> Cu 2+ + 1e-
R: Cu 1+ + 1e- –> Cu

Question 5

Oxidation numbers are…

Answer 5

Actual or hypothetical charges assigned to an atom using a set of accepted rules or patterns

Question 6

What are the oxidation number rules?

Answer 6

1. Pure element = 0
2. Ion = the ion charge
3. Hydrogen = 1+ except in metal hydrides (NaH) -1
4. Oxygen = -2 except in peroxides (OF2)
5. Molecular compounds without H,O, the more electronegative