Why butane has zero boiling point?At room temperature it exists as a gas but below zero degrees does it freezes?

Butane does indeed boil at about a degree below 32 degrees Fahrenheit, but this is true only at normal atmospheric pressure.Heating a liquid involves two significant factors: the heat, which makes the molecules of liquid more active and increases the likelihood they will transform into a gas, and ambient pressure, which tries to push them back into liquid form.If the heat factor dominates, the liquid rapidly turns to gas, and if the temperature is high enough, it boils.If the pressure factor dominates, the liquid can still evaporate, but slowly. This can be seen routinely with water, which slowly evaporates unless it is heated to the boiling point. In a lighter, the liquid is enclosed. Some gas evaporates, but as pressure builds, it pushes down on the liquid and stops it from boiling. When the lighter is used, a little of the gas is let out - enough so it can be lit, but never enough to cause the liquid to boil.If the lighter were fully opened and the pressure released, the liquid butane would quickly boil away. A pressure cooker displays the same process.Normally, if water is heated to 212 degrees it boils, with steam escaping quickly so the temperature is maintained at 212. But a pressure cooker reaches higher temperatures by preventing steam from escaping easily, increasing the pressure inside. The increased pressure allows the liquid to reach a higher temperature before boiling, so food can be cooked faster.Conversely, if water is heated at lower pressure, on a mountain or in an airplane, for example, it boils at a lower temperature (it will never reach 212 degrees) - which is why you can’t get a decent cup of tea when you’re flying