Gay-Lussac's Law states that the pressure of a sample of gas at constant volume, is directly proportional to its temperature in Kelvin. When any three of the four quantities in the equation are known, the fourth can be calculated. For example, we've known P 1 , T 1 and P 2 , the T 2 can be:. The measurement of space taken by a substance, it is length cubed, typical units are L, mL and m3.
The graph of the Gay-Lussac's law is a plot of pressure versus temperature. The pressure-temperature graph is as follows:. From the above graph, pressure increases with an increase in temperature, and vice versa. Thus, pressure is directly proportional to temperature. The graph is plotted at constant volume and a constant amount of gas, and temperature is expressed in the kelvin i. Pressure is on the y -axis, and temperature is on the x -axis.
French chemist Joseph Louis Gay-Lussac proposed two fundamental laws of gases in the early 19th century. His daring ascents in hydrogen-filled balloons were key to his investigations. His comfortable existence as the privately tutored son of a well-to-do lawyer was disrupted by political and social upheavals: his tutor fled, and his father was imprisoned.
John J. This lesson provides an introduction to Pressure, Temperature and Gay-Lussac's Gas Law, using as an example the Deflategate controversy that took place in the sport of American Football in January The main learning objectives are: 1 to define temperature and pressure; 2 to introduce the concepts of absolute pressure and absolute temperature, including the use of Kelvin measurement units; 3 to use Gay-Lussac's law to predict how the pressure of a fixed container of gas, such as a football, will change due to an increase or decrease in temperature; 4 to compare predictions from a physical law with experimental measurements of the same quantity; 5 to introduce the concept of measurement error and to discuss sources of uncertainty in pressure and temperature measurements; and 6 to use the Ideal Gas Law to compute the amount of gas that would need to be added or removed from a fixed volume of gas, held at constant temperature, to achieve a given increase or decrease in pressure. This lesson has no pre-requisites and should take students about an hour to complete.