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Give the reactiosn at thje negagtive qand positive elctroces of alkiline fuel cell and overall reaction
Negative: H2 + 2OH→ 2e + 2H₂O Positive: 4e + 2H₂O + O2→ 4OН- Overall reaction 2H₂ + O2→ 2H2O E=1.23V
What does an increase in temp do to emf what does an increase in pressure do to emf
Decreasse Increase
Equation that occurs at oxygen electrode Equation that occurs at ethanol electrode Overall reaction
4e + 4H+ +O2→ 2H2O E=1.23V C2H5OH + 3H2O → 2CO₂ + 12H+ + 12e C2H5OH + 3O2 → 2CO₂ + 3H2O
Hack for buffer calcs If you adding an alkali what do you do to ha and a- If you adding an acid what do you do to ha and a-
If adding alkali you add the moles to a- If adding alkali you minus the moles of ha If adding acid you add the moles to ha If adding acid you minus the moles of a-
Explain why the enthalpy of lattice dissociation for sodium oxide is greater than the enthalpy of lattice dissociation for sodium chloride.
(e) Oxide ions M1 have higher (negative) charge OR smaller size OR higher charge density/higher charge:size ratio (than chloride ions). M2 stronger attraction between (O2- and Na+/oppositely charged) ions
Explain why the enthalpy of hydration of fluoride ions is more negative than the enthalpy of hydration of chloride ions.
M1 fluoride ions/F− (ions) are smaller OR M1 F− has a higher charge density Do not accept fluorine atoms/ions are smaller M2 stronger attraction (of fluoride ion) to δ+ on H/ electron deficient H (in water)