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Extraction of Pure Elements from Nature Which elements are easy?

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Presentation on theme: "Extraction of Pure Elements from Nature Which elements are easy?"— Presentation transcript:

1 Extraction of Pure Elements from Nature Which elements are easy?

2 Easy elements are gases that exist in the elemental form N 2, O 2, noble gases Obtained by distillation of cooled, liquified air.

3 Preview

4 Extraction of Metals All metals exist as cations in chemical compounds in the crust. Key: reducing the cations to the neutral metal. Example: Fe 2 O 3 has Fe 3+ ions. To obtain Fe metal, need to add 3 electrons to each Fe 3+ ion.

5 What we’ll find.

6 Review of Thermodynamic Control of Reactions Enthalpy:  H depends on bond strength reactions favored by negative  H (which is forming stronger bonds) Entropy:  S depends on randomness (disorder) reactions favored by positive  S (increasing disorder, particularly formation of gases)

7 Consider the decomposition of Fe 2 O 3

8 Reaction with C: C(s) 0 5.6 CO2(g) -393.5 213 -394.4

9 Consider the decomposition of HgO

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12 Aluminum Production


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