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Chemical rxns can produce electricity = galvanic cell OR

Chemical rxns can produce electricity = galvanic cell OR Electrical energy used to carry out chemical reactions = electrolytic cell. Use of electricity make the reaction NONSPONTANEOUS (it needs help). Galvanic Cell. Chemical Potential Energy. Electrical Potential Energy.

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Chemical rxns can produce electricity = galvanic cell OR

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  1. Chemical rxns can produce electricity = galvanic cell OR • Electrical energy used to carry out chemical reactions = electrolytic cell Use of electricity make the reaction NONSPONTANEOUS (it needs help)

  2. Galvanic Cell Chemical Potential Energy Electrical Potential Energy Electrolytic Cell

  3. Electrolytic Cells • Nonspontaneous • Need battery or power supply • Consumes energy = endothermic

  4. What’s the difference? Electrons are flowing in opposite direction anode catode Electrolytic Cell An Ox ate a Fat Red Cat Use Table J, but opposite More active metal = cathode = negative Less active metal = anode = positive Galvanic Cell An Ox ate a Fat Red Cat Use Table J More active metal = anode = negative Less active metal = cathode = positive

  5. NONSPONTANEOUS e- flow Anode to Cathode But from + to – (opposite then we’d think) That’s why we use the battery SPONTANEOUS e- flow Anode to Cathode from – to + (just like we’d think) That’s why it’s spontaneous

  6. A POX on Electrolytic Cells • Anode – Positive – Oxidation A pox = a disease And electrolytic cell behave differently like they are disease?!

  7. Various types of electrolytic cells • Fused Salt Cells – used to purify metals (Fused means melted = molten salt cell) • Add NaCl (s) and melt it • Now NaCl (l) • Why melt it?! • Why add CaCl2(s)??! • Na+1 is reduce to Na(l) • Na(l) is less dense then NaCl(l) so it floats on top • 20,000 tons of Na are produce this way in the US every year

  8. Various types of electrolytic cells 2. Electroplating A layer of a second metal is deposited on the metal electrode that acts as the cathode • Used to enhance the appearance of metal objects and protect them from corrosion.

  9. Various types of electrolytic cells 2. Electroplating • cathode = object to be plated • anode - made of metal want to plate on object • solution: contains ions of plating metal

  10. 3. Electrolysis of H2O H2 is produced at one electrode, O2 at the other. 2H2O + energy 2H2 + O2 Can you tell from the picture which electrode is producing H2?

  11. What do every one of these have in common?

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