Flashcards
Enthalpy
Flashcards do conjunto (19)
- 1What is H?Heat energy of a system
- 2ΔH=H(products) - H(reactants)
- 3ΔfHϴΔH When 1 MOLE compound formed from elements under ϴ
- 4ΔfHϴ of an element0
- 5ΔcHϴOne mole compound completely reacted w/ O2 under ϴ
- 6ΔneutHϴAcid+Base = 1 MOLE H2O under ϴ
- 7Effect of doubling vol. in ΔneutHϴ on T changeDouble T = double E however spread over twice the volume so no change
- 8How is ΔrHϴ determined from q?q = E gained by surroundings
So ΔrHϴ must be the opposite - 9What is m in reaction btw. 2 solutions?Solution itself is the immediate surroundings
So M of both - 10What is C?'C needed to ^ 1g substance by 1K
- 11Inaccuracies w/ experimental ΔcHϴ (3)Incomplete combustion as CO or Soot
Evaporation of methanol on wick
Heat loss to surounding other than water - 12Δ btw. experimental and databookExperimental less exothermic due to less efficient energy transfer
- 13How to increase accuracy (2)Use a draught screen could minimise erros of heat loss
Input O2 gas ensure complete combustion - 14Proving that a reactant is in excess in ΔrHϴCalculate n of limiting reagant
This gives you n of excess required
Calculate actual n of excess - 15Calculating ΔrH from bond enthalpiesΔrH=ΣH(r) - ΣH(p)
- 16What conditions are required when working out these reactions?All species must be gaseous, therefore it can't be standard if say H2O is involved.
Can still work out the standard, but would need to account for ΔrH of H2O(g) -> H2O(l) - 17What is average bond enthalpyE required to break 1 mole of bonds in a gaseous molecule
- 18What is DeltarH from formation?P-R
- 19What's enthalpy change of reaction from combustion?R-P
Informações
- Descrição
- FlashCards sobre Enthalpy, criado por I Shouldn't be awake em 24-04-2018.
- Criado por
- I Shouldn't be awake
- Visualizações
- 13
- Avaliação