Understanding Alcohol Ignition: The Science and Percentage Explained

[shimun]

1. Can anyone explain in basic way, when alcohol begins to burn from external fire touch, precisely in procentage. as we kown vodka 40% of alcohol don't fire up.
2. Can anyone answer me in basic way, why is what ?

 

[AidenFlamel]

2. Can anyone answer me in basic way, why is what ?

I don't get to understand what you want to know...

 

[Borek]

as we kown vodka 40% of alcohol don't fire up.

Sure it does, you just have to know how to ignite it.

I doubt you will get a single number as a lot depends on how you define ignition conditions.

 

[Ygggdrasil]

Here's a document that contains the flash points of ethanol:water solutions (see table 4): https://engage.aiche.org/HigherLogi...=e53a8ccc-48b1-4e3b-b59f-bb579cc5132b&ssopc=1

According to the data, solutions below about 20% ethanol (40 proof) will not ignite at room temperature (though 20% ethanol would ignite at slightly above room temperature, so it would not be surprising if you could light it on fire).

 

[marjudo]

It's depending of the % of water and the % of alchohol I think.

 

[hilbert2]

The concentration of ethanol in the water has to be high enough for its vapor pressure to be within flammability limits at that temperature. The vapor pressure does not increase linearly from zero to the value of pure ethanol when the alcohol percentage is increased, so it's difficult to calculate the minimum concentration without having experimental data, but the "proof" scale of alcohol percentage, where 100 proof is equal to 50% vol. of ethanol is based on the approximate minimum flammable concentration at room temperature.