Unit 5: Electrochemistry

Question 1

what is oxidation

Answer 1

loss of electrons

ex. Al ~ Al+3

Question 2

what is reduction

Answer 2

gain of electrons

ex. Fe +3 ~ Fe

Question 3

Oxidation and reduction always happen together. this is called?

Answer 3

a Redox Reaction

Question 4

what is the oxidizing agent

Answer 4

( substance that does the oxidation do other species )

OR

(the one being reduced)

Question 5

what is the reducing agent

Answer 5

( substance that does the reduction do other species )

OR

(the one being oxidized)

Question 6

what is the oxidizing and reduction agent in this reaction

Cu +2 + 2 e- ~ Cu

Mg ~ Mg 2+ + 2 e-

Answer 6

OxidizIng Agent = Cu 2+

Reducing Agent = Mg

Question 7

what does balancing half reactions mean?

Answer 7

balancing their charge and amount of atoms

Question 8

what is MAJOR OH-

Answer 8

Major = balancing amount of “major” atoms ( not O and H )

O = Balancing O by adding same amount of H2O

H = balancing H by adding same amount of H+

- = balance charges by adding electrons

Question 9

what is the difference of steps between acidic and basic

Answer 9

acidic = MAJOR OH - method

basic = MAJOR OH - with a bonus step, adding OH- for all the H+

Then in the side with H+, combine Oh- and H+ to create H2O

Cancel out the water in both sides

Question 10

What is oxidation for ion in elemental form

Answer 10

0

Question 11

Oxidation of Common Atoms

Answer 11

Group 1: +1

Group 2: +2

Halogens ( group 17 ) : -1

Oxygen = -2

Aluminum = +3

Question 12

the sum of positive and negative charges in a compound =?

Answer 12

0

Question 13

the sun if positive and negative ions in a polyatomic ion ( 1 or more ion, ex: MnO4 - ) =?

Answer 13

equals charge of ion

so MnO4 - = -1