Redox Basic Knowledge

Question 1

What is an anion?

Answer 1

Negative Ion

Question 2

What is a cation?

Answer 2

Positive Ion

Question 3

What is an external circuit?

Answer 3

The path (wire) that travels anode to cathode that electrons travel through.

Question 4

What is an inert electrode?

Answer 4

Solid that conducts electrons but isn’t involved in the reaction.

Question 5

What are the 2 most common substances used for inert electrodes?

Answer 5

1. Pt(s)

2. C(s)

Question 6

What is an electrolyte?

Answer 6

A substance that conducts electricity in aqueous solution because it contains ions.

Question 7

Why does hydrogen not have to be the standard reference cell?

Answer 7

• Reference cell is an arbitrary designation.

- Difference between any 2 voltages is the same

Question 8

1amp is = to what?

Answer 8

1C/s

Question 9

On a table of reduction half reactions halogen elements are always…

Answer 9

OAs

Question 10

What 3 pieces of knowledge do you need to solve most Faraday Law questions?

Answer 10

1. Faraday Constant
2. 1A=1C/s
3. A half reaction

Question 11

What is the main principle for Cathodic protection?

Answer 11

Use a stronger SRA then the substance your protecting.

Question 12

Draw the SOA/SRA diagram for the rust reaction that occurs on the Redox chart.

Answer 12

SOA O2 + 2H2O(l)
↘️
Fe(s) SRA

Question 13

Show the rust reaction being bypassed using the principle of Cathodic protection.

Answer 13

SOA O2 + 2H2O(l)
⬇️ ↘️
↘️ Fe(s) Not SRA
↘️
➡️ Mg(s) SRA

Question 14

On a table of reduction half reactions metal ions are usually…

Answer 14

OAs

Question 15

What metals would make good sacrificial anodes for the rust reaction?

Answer 15

Anything lower than Fe(s) that is inexpensive to produce. (Stronger SRA)

Question 16

What is the chlorine anomaly?

Answer 16

Anomaly that occurs during electrolysis of sea water (brine).
SRA should be water but is actually Cl-(aq)

Question 23

What is the oxidation number of chlorine?

Answer 23

0

Question 23

What is the oxidation number of simple ions such as Fe2+?

Answer 23

+2

Question 24

What is the oxidation number of hydrogen in most compounds?

Ex: H2O

Answer 24

+1

Question 24

What is the oxidation number of hydrogen when attached to a metal (hydride)?
Ex:LiH(s)

Answer 24

-1

Question 25

What is the oxidation number of oxygen in most compounds?

Ex: H2O

Answer 25

-2

Question 25

What is the oxidation number of oxygen in peroxides?

Ex. H2O2

Answer 25

-1

Question 25

What is the oxidation number of group 1A elements?

Ex. NaCl

Answer 25

+1

Question 25

What is the oxidation number of group 2A elements?

Ex. MgCl2

Answer 25

+2

Question 25

What is the oxidation number of fluorine in a compound? | Ex. NaF

Answer 25

-1

Question 25

All other oxidation numbers are assigned such that...

Answer 25

The sum of the oxidation numbers = the charge.

Question 25

Oxidation numbers are assigned on a...

Answer 25

Per atom basis.

Question 25

What is oxidation?

Answer 25

Loss of electrons.

Question 25

What is reduction?

Answer 25

Gain of electrons.

Question 26

If the oxidation number goes up what has occurred?

Answer 26

Oxidation.

Question 26

If the oxidation number goes down what has occured?

Answer 26

Reduction.

Question 26

In an oxidation half reaction electrons are on what side?

Answer 26

Product.

Question 26

In an reduction half reaction electrons are on what side?

Answer 26

Reactant.

Question 26

An oxidizing agent losses or gains electrons?

Answer 26

Gains.

Question 26

An reducing agent losses or gains electrons?

Answer 26

Losses.

Question 26

If a reaction contains atoms and the oxidation numbers change then the reaction is considered redox or not redox?

Answer 26

Redox.

Question 26

What is disproportionate?

Answer 26

When a substance is both OA and RA.

Question 27

On a table of reduction half reactions on which side are the electrons placed?

Answer 27

Reactants

Question 28

On a table of reduction half reactions where is the SOA and SRA located?

Answer 28

Top left and Bottom right (respectively).

Question 29

On a table of reduction half reactions how do you determine if a reaction is spontaneous or non-spontaneous?

Answer 29

OA above RA=Spontaneous | RA above OA=Non-Spontaneous

Question 31

On a table of reduction half reactions metal elements are always...

Answer 31

RAs

Question 33

On a table of reduction half reactions halogen ions are always...

Answer 33

RAs

Question 35

On a table of reduction half reactions the SOA is written...

Answer 35

As is

Question 37

On a table of reduction half reactions the SRA is written...

Answer 37

Reversed

Question 39

When doing stoich the molar ratio is always...

Answer 39

R/G

Question 41

What are the 11 steps of titration?

Answer 41

3. Fill burette to 0 mark 4. Record initial Volume of titrant 5. Pipet 10mL of sample into E. Flask 7. Slowly add titrant to sample until 1 drop causes color change 8. Record final volume of titrant

Question 43

In titration the substance being titrated is in the...

Answer 43

Flask

Question 45

What are the 5 constants in electrochemical cells, both voltaic and electrolytic?

Answer 45

1. GERC 2. LEOA 3. Anions migrate to Anode 4. Cations migrate to Cathode 5. E- flow from anode to cathode

Question 47

What are 3 charecteristics of voltaic cells?

Answer 47

1. Chemical ➡️ Electrical 2. Spontaneous 3. Positive Voltage (E net is +)

Question 49

What are the 3 charecteristics of electrolytic cells?

Answer 49

1. Electrical ➡️ Chemical 2. Non-Spontanious 3. Negative Voltage (E net is -)