Test 3: Oxidation-Reduction Reactions

Question 1

In acid-base and precipitation reactions, ions ____ but they maintain the ___.

Answer 1

swap partners, same charge.

Question 2

In oxidation-reduction (redox) reactions, atoms gain or lose electrons by

Answer 2

trading or sharing in different ways

Question 3

Oxidation number

Answer 3

a number assigned to an element in chemical combination which represents the number of electrons lost (or gained, if the number is negative), by an atom of that element in the compound.

Question 4

To correctly identify and characterize redox reactions we need a way to

Answer 4

track electron
ownership and transfer.

Question 5

How do we track electron ownership and transfer?

Answer 5

by calculating the oxidation number

Question 6

What is the first step when assigning an oxidation number?

Answer 6

determine if the species is a neutral
(elemental), an ion or ionic compound, or a covalent compound

Question 7

The oxidation number for any neutral element in its standard state is

Answer 7

zero

Question 8

The oxidation number for any ion or ions in an ionic compound

Answer 8

the charge of the
ion.

Question 9

The sum of the oxidation numbers in any molecule or polyatomic ion equals

Answer 9

the total overall charge of that molecule or polyatomic ion.

Question 10

For covalent compounds, use the following assignments in exactly this order

Answer 10

H = +1, F = -1, O = -2, Cl, Br, I = -1

Question 11

Oxidation occurs when

Answer 11

something loses electrons

Question 12

Reduction occurs when

Answer 12

something gains electrons (the charge is reduced)

Question 13

A polyatomic ion is bound together by a

Answer 13

covalent bond

Question 14

OiL RiG is a way to remember

Answer 14

Oxidation Loses & Reduction Gains (electrons)