Explain this phenomenon a drop of petrol makes a finger colder than a drop of water

Petrol takes its latent heat of vaporization from the finger. Petrol doesn't have the chemical bond that water has so therefore less surface tension so it evaporates (dries) much more quickly. When it evaporates it cools your skin so it feel cold to the touch.

Explanation:

Also, in the future it may help to adjust the subject since you have this in the spanish category instead of science. (Hope this helps!) :)