Ellingham Diagrams and Cu

Question 1

What are different ores of Cu?

Answer 1

Malachite, azurite, chalcolite, cuprite

Question 2

What are malachite and azurite?

Answer 2

Cu CO3’s; ar green and blue

Question 3

What is chalcolite?

Answer 3

A Cu SO4; grey

Question 4

What is cuprite?

Answer 4

A Cu O; deep red

Question 5

How was Cu extracted from ores?

Answer 5

Roasting causes dissociation

Question 6

When was Cu extraction via roasting started?

Answer 6

6000-5000BC

Question 7

What are axes of an Ellingham diagram?

Answer 7

y-axis = Gibb's Free Energy
x-axis = Temperature

Question 8

What does an Ellingham diagram display?

Answer 8

How strongly metal oxides are bound (strength of bond with O)

Question 9

What does a kink in the gradient show?

Answer 9

A change in state

Question 10

Are more reactive elements at the top or bottom of the graph?

Answer 10

Bottom

Question 11

What is the most unreactive element on the graph?

Answer 11

Ag; shown as Ag2O; dissociates @100 Celsius

Question 12

What is the most reactive element on the graph?

Answer 12

Ca; shown as CaO; allows Ca to reduce CuO via displacement

Question 13

What element is not present on the graph?

Answer 13

Au; is inert

Question 14

Where does Hg2O melt, and where does it dissociate?

Answer 14

300 Celsius melts, 400 Celsius dissociates

Question 15

What is the general rule to the relation between Temperature and bond to oxygen?

Answer 15

Increased T = weaker bond to O

Question 16

What is the exemption to the general rule of T and bond to O?

Answer 16

CO

Question 17

What compounds does CO bisect?

Answer 17

Cu2O and FeO

Question 18

At what temperature can C reduce Cu2O?

Answer 18

~100 Celsius

Question 19

At what temperature can C reduce FeO

Answer 19

~1000 Celsius

Question 20

What oxide does iron oxide exist as typically?

Answer 20

Fe2O3; becomes FeO if heated to 700 Celsius