Module 5-8 Unit 2

Question 1

Electrochemistry

Answer 1

the study of converting chemical energy to electrical energy, and vice versa

Question 2

Electrochemical cell

Answer 2

a device that generates electrical energy from chemical reactions, and vice versa

Question 3

Voltaic (galvanic)

Answer 3

Spontaneous reactions in the cell use a chemical reaction to generate electricity

Question 4

Electrolyic Cells

Answer 4

Nonspontaneous reactions in the cell use electricity to force a chemical reaction to take place

Question 5

Half Cells

Answer 5

One of the two compartments in an electrochemical cell that houses a half reaction

Question 6

Electrode

Answer 6

A solid electrical conductor in a half-cell in an electrochemical cell

Question 7

Electrolyte

Answer 7

An aqeous electrical conductor in the half-cell of an electrochemical cell

Question 8

RED CAT

FAT CAT

Cathode

Answer 8

• REDuction occurs at the CAThode
• CAThode gets FATter as the reaction procedes

Gains electrons, mass increases

Question 9

AN OX

FAT CAT

Anode

Answer 9

• the ANode is the site of OXidation
• electrons travel from From Anode To CAThode

mass decreases

Question 10

Salt Bridge

Answer 10

U shaped tube containing an aqueous electrolyte connecting both half cells, preventing build up of charge within a cell

Question 11

Porus boundary

Answer 11

AN unglazed porcelain cup containing an electrolyte that sits in a container of another electrolyte, connecting both half cells, preventing build up of charge within a cell

Question 12

Anode and Cathode in Voltaic cells

Answer 12

An - Negative (repelling electrons)
Cath - positive (attracting electrons)

Spontaneous

Question 13

Anode and cathode in Electrolytic cells

Answer 13

An - Positive (Attracting electrons)
Cath - Negative (Repelling electrons)

Nonspontanous

Question 14

Cell notation

Answer 14

Reactant|Product||Reactant|Product
Anode —-> Cathode

Question 15

Dry Cell

Answer 15

a Voltaic Cell where the electrolyte has been thickened into a paste

Question 16

Battery

Answer 16

Voltaic Cells connected in series

Question 17

Primary battery

Answer 17

a disposable battery, when reactants are used up they can’t be used anymore

Question 18

Secondary battery

Answer 18

a reachargable battery, where reactants are used up and can be recharged using electricity

Question 19

Fuel Cell

Answer 19

A battery that can be refuelled by running reactants through the cell and products flow out through the electrolyte membrane

Question 20

Corrosion

Answer 20

oxidation of metals exposed to the environment

a spontaneous redox reaction

Question 21

Formation of Rust

4 steps

Answer 21

1) Anode =Iron (eaten away)
2) Cathode = impurity in the iron
3) Elecrolyte = carbonc acid (CO2 combines with rain water)
4) “Wire” = iron itself

Question 22

How to protect iron from corrosion

Answer 22

• protective coating
• Create an alloy
• Galvanise (protective layer)
• Cathodic prevention (saccrificial anode)

Question 23

Electrolysis

Answer 23

process in an electrolytic cell where electricity is used to drive a nonspontaneous chemical reaction

Question 24

Overpotential

Answer 24

potential difference (voltage) beyond the calculated value for the cell potential nessesary to drive the reacton

Question 25

Electrorefining

Answer 25

Using electrolysis to obtain high grade metals at the cathode from impure metals at the annode