Boyles law what is k

Boyle's law was first formulated as an experimental gas law which described how the pressure of a gas decreased when the volume of said gas increased. A more formal description of Boyle's law states that the pressure exerted by a mass of ideal gas is inversely proportional to the volume it occupies if temperature and amount of gas remain unchanged. This is where a k is usually seen, as it is often used to describe a constant value. So the k you are referring to is. We need to keep the amount of gas, which represents the number of moles , and the temperature constant.

Since R is a constant already, the ideal gas law becomes. If you trap a sample of air and measure its volume at different pressures constant temperature , then you can determine a relation between volume and pressure.

If you do this experiment, you will find that as the pressure of a gas sample increases, its volume decreases. In other words, the volume of a gas sample at constant temperature is inversely proportional to its pressure.

The product of the pressure multiplied by the volume is a constant:. This relationship is called Boyle's Law , after Robert Boyle , who discovered it in Its pressure is now 3.

What was the original pressure of the helium? It's always a good idea to write down the values of all known variables, indicating whether the values are for initial or final states. Boyle's Law problems are essentially special cases of the Ideal Gas Law:. Did you notice that the units for the pressure are in cm Hg? You may wish to convert this to a more common unit, such as millimeters of mercury, atmospheres, or pascals.

Actively scan device characteristics for identification. Boyle showed that the volume of air trapped by a liquid in the closed short limb of a J-shaped tube decreased in exact proportion to the pressure produced by the liquid in the long part of the tube.

The trapped air acted much like a spring, exerting a force opposing its compression. The law itself can be stated as follows: for a fixed amount of an ideal gas kept at a fixed temperature, P pressure and V volume are inversely proportional—that is, when one doubles, the other is reduced by half. Remember that these relations hold true only if the number of molecules n and the temperature T are both constant.

The table below shows pressure and volume data for a set amount of gas at a constant temperature. A graph of the data in the table further illustrates the inverse relationship nature of Boyle's Law see figure below. Boyle's Law can be used to compare changing conditions for a gas.

The mathematical relationship of Boyle's Law becomes:. This equation can be used to calculate any one of the four quantities if the other three are known. Calculate the new pressure of the gas.