Gay-Lussac's Law Calculator

Gay-Lussac's law states that the pressure of a given mass of gas is directly proportional to its absolute temperature, provided the volume remains constant. Mathematically, this is expressed as P1 / T1 = P2 / T2, where P represents pressure and T represents absolute temperature measured in Kelvin. If temperature increases, kinetic energy rises, causing molecules to collide with container walls more forcefully and driving pressure up. When factoring in the universal gas law, the relationship expands to include moles (n) and volume (V) using the ideal gas equation: P * V = n * R * T, where R is the universal gas constant (8.314 J/(mol*K)).

Imagine a rigid steel cylinder containing a fixed volume of gas. Initially, the pressure gauge reads 150 kPa at a room temperature of 298 K. If you heat the cylinder until the internal pressure reaches 200 kPa, what is the new temperature of the gas? Using the formula T2 = P2 * (T1 / P1), we substitute our known values: T2 = 200 * (298 / 150). First, divide 298 by 150 to get approximately 1.9867. Multiplying this result by 200 gives a final absolute temperature of roughly 397.33 Kelvin, or about 124.18 degrees Celsius.

Always convert your temperature inputs to Kelvin before performing any calculations, as using Celsius or Fahrenheit will yield incorrect results. Ensure that your volume remains strictly constant throughout the scenario, since any expansion or contraction will invalidate the direct pressure-temperature proportionality. Double-check your pressure units to ensure consistency—do not mix atmospheres with kilopascals without proper conversion.