Combined Gas Law The combined gas law combines Boyle’s Law and Charles’ Law

Combined Gas Law Boyle’s Law P 1 V 1 = P 2 V 2 Boyle’s Law P 1 V 1 = P 2 V 2 Charles’ Law Charles’ Law V 1 = V 2 V 1 = V 2 T 1 T 2 T 1 T 2 Combined Gas Law Combined Gas Law P 1 V 1 = P 2 V 2 T 1 T 2 T 1 T 2

Units of Pressure Atmospheres =1 atm is the average atmospheric pressure at sea level Torr = equal to 1/760 of an atmosphere millimeters of mercury = 1 mm Hg is the same as 1 Torr, or 1/760 atm Kilopascals = there are kPa in 1 atm Standard temperature and pressure (stp)= A set of conditions defined as 273 K and 1 atm

Converting to Kelvin Kelvin is abbreviated as K. To convert, just add 273 to whatever the Celsius temperature is. Example: 30° Celsius = = 303 K

Combined Gas Law For example: If I initially have a gas at a pressure of 12 atm, a volume of 23 L and a temperature of 200 K, then I raise the pressure to 14 atm and increase the temperature to 300 K, what is the new volume of the gas? For example: If I initially have a gas at a pressure of 12 atm, a volume of 23 L and a temperature of 200 K, then I raise the pressure to 14 atm and increase the temperature to 300 K, what is the new volume of the gas?

Combined Gas Law Begin by converting to Kelvin. It is not necessary in this problem. Begin by converting to Kelvin. It is not necessary in this problem.

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = P 1 = V 1 = V 1 = T 1 = T 1 = P 2 = P 2 = V 2 = V 2 = T 2 = T 2 =

Combined Gas Laws Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = V 1 = T 1 = T 1 = P 2 = P 2 = V 2 = V 2 = T 2 = T 2 =

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = 23 L V 1 = 23 L T 1 = T 1 = P 2 = P 2 = V 2 = V 2 = T 2 = T 2 =

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = 23 L V 1 = 23 L T 1 = 200K T 1 = 200K P 2 = P 2 = V 2 = V 2 = T 2 = T 2 =

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = 23 L V 1 = 23 L T 1 = 200K T 1 = 200K P 2 = 14 atm P 2 = 14 atm V 2 = V 2 = T 2 = T 2 =

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = 23 L V 1 = 23 L T 1 = 200K T 1 = 200K P 2 = 14 atm P 2 = 14 atm V 2 = x V 2 = x T 2 = T 2 =

Combined Gas Law Next, write down the information you know and want to know. Next, write down the information you know and want to know. P 1 = 12 atm P 1 = 12 atm V 1 = 23 L V 1 = 23 L T 1 = 200 K T 1 = 200 K P 2 = 14 atm P 2 = 14 atm V 2 = x V 2 = x T 2 = 300 K T 2 = 300 K

Combined Gas Law Now plug in the information you have... Now plug in the information you have... P 1 V 1 = P 2 V 2 T 1 T 2 T 1 T 2 12atm(23L) = 14 atm (x) 200K 300K 200K 300K

Combined Gas Law Cross multiply to solve for x Cross multiply to solve for x 12atm(23 L)(300K) = 200 K (14L)(x) 12atm(23 L)(300K) = 200 K (14L)(x) = 2800x = 2800x x = Liters x = Liters