The Pressure is linearly proportional to the Kelvin temperature, that is, if the Kelvin temperature increases by a factor of 2, then P doubles also. Kelvin invented a more precise thermometer. Negative temperature on the Celsius scale has no physical meaning. For fixed P, all gases experimentally extrapolate to an apparent zero volume at minus 273.15 Celsius. This is considered to be the lowest possible temperature.
Gas Volume is proportional to the molecular weight.
The pressure is due to molecular collisions with the wall. The ideal gas constant R is the same for all gases. The weight of the liquid column balances the pressure of the atmosphere. If atmospheric pressure decreases as in a hurricane, the liquid column becomes shorter. The height of the liquid column is inversely proportional to the gravitational constant g.