Galvanic cells - Introduction

Question 1

What is a galvanic cell?

Also known as electrochemical cell

Answer 1

A device that converts chemical energy into electrical energy

Question 2

What type of reations occur in galvanic cells?

Answer 2

Redox reactions

Question 3

Describe the set-up of a Daniell Galvanic Cell

Answer 3

• Two containers filled with electrolyte and have electrodes each
• Electrodes are connected by wires and voltmeter
• Salt-bridge connects the two electrolytes

Question 4

What is the Anode?
List all properties of the anode

5 properties

Answer 4

Anode is site of oxidation
1. Negatively charged electrode
2. Elecrons flow away from anode
3. Anions flow towards anode
4. If not inert electrode - electrode loses mass
5. Reductant found at anode

Anode is considered one half-cell

Question 5

What is Cathode?
List all properties of cathode

5 properties

Answer 5

Cathode is site of reduction
1. Positively charged electrode
2. Electrons flow towards cathode
3. Cations flow towards cathode
4. If not inert electrode - electrode gains mass
5. Oxidan is dound at cathode

Cathode is considered 1 half cell

Question 6

What is the external circuit in a galvanic cell

Answer 6

The wires, voltmeter, load and anything that’s a connected component

Question 7

What is the internal circuit of a galvanic cell?

Answer 7

The salt-bridge or the part of the circuit found within the solution

Question 8

What type of redox reactions do glavanic cells work?

Answer 8

Spontaneous redox reactions

Question 9

What is a spontaneous reaction?

Answer 9

A reaction that proceeds on its own without the need of external supply of energy

Question 10

What type of oxidant and reductant react in a spontaneous redox reaction?

Answer 10

Only a strong oxidant reacting with a strong reductant will create a spontaneous redox reaction

Can use electrochemical series to identify

Question 11

What is a battery?

Answer 11

Two or more connected cells in a series

Question 12

What is the Salt-bridge

Answer 12

The component that provides supply of mobile ions that carry a charge through the solution of a galvanic cell

Question 13

What conditions must a salt-bridge pass to be used in a galvanic cell?

Answer 13

• Must not involve itself in side reactions with any other constituents of the cell
• Must be a salt
• Must be able to dissascosciate into cations and anions in electrolyte

Question 14

What are the 2 purposes of a salt-bridge?

Answer 14

1. Complete the circuit
2. Balance charge

Question 15

Explain how a salt-bridge completes the circuit in a galvanic cell

Answer 15

It connects the two electrolyte solutions and ensures a supply of anions and cations are present to maintain flow of charge through cell

Question 16

Explain how a salt-bridge helps balance the charge in a cell

Answer 16

It provides a supply of cations and anions. Charged ions move…idk… to maintain electric neutrality at electrodes.