[jadelamlam]

The autoignition temp of n-butane(straight chain) is 288 degree Celcius while that of
isobutane(branched chain) is 460 degree Celcius.
The flash point of n-butane is -60 degree Celsius while that of isobutane is -83 degree Celcius.

I was confused by these..Why does n-butane have a higher flash point but a lower autoignition temperature?
(same case in n-octane and isooctane)

[Hunter2]

Check definition of autoignition temperature and flash point.