Chp 6 Flashcards
1
Q
Define enthalpy
A
- measure of total energy in system
- delta H
1
Q
Exothermic
A
Exo temp increase
Negative sign
Freezing water
Combustion
Dissolving NaOH in water
2
Q
Endothermic
A
Endo temp decrease
Positive sign
Melting ice
Evaporating water
Photosynthesis
3
Q
What are the stantard conditions
A
- 100kPa
- 298K
- stantard enthalpy change
- deltaH theta
4
Q
define stantard enthalpy change of reaction (deltaHR theta)
A
- enthalpy change that occurs when equation quantities of materials react under stantard conditions
5
Q
Define SEC of combustion
A
- when one mole of substance is completley burned in excess oxygen
6
Q
Define SEC of neutralisation
A
one mole of water produced by neutralisation of an acid w alkali
7
Q
Define SEC of formation
A
one mole of substance formed from its elements in their stantard states
8
Q
Define SEC of atomisation
A
one mole of gaseous atoms formed from element in its stantard state
9
Q
Define bond enthalpy
A
one mole of bond in gaseous state is broken
bond breaking is endothermic (needs energy)
