Vapour pressure Flashcards
1
Q
what is vapour pressure
A
pressure exerted by a pure substance in a system containing only the vapour and condensed phase of a substance
2
Q
what are flammability limits
A
- the limits within which a combustion reaction occurs
at the upper explosive limit - gas will burn
at the lower explosive limit - gas ignites and burns
3
Q
calculating the lower flammabilty limit
A
stoichiometric ratio of fuel : oxygen x 100/21
4
Q
flash point
A
- minimum temperature at which vapour produced by a liquid can be ignited momentarily in air
low flash point = higher vapour temperature
5
Q
fire point
A
minimum temperature at which the vapour produced by a liquid sustains combustion after ignition in air
- often a few degrees higher than the flash point
6
Q
Ignition temperature
A
the temperature something will spontaneously ignite (auto ignition)
reflects the Ea