This also has practice with Boyle's Law, Charles' Law, and Gay-Lussac's Law, which can be derived from the combined gas law: 0 1 2 3 Combined Gas Law At conditions of Becomes Also Known As \(\frac{P_1 V_1}{T_1}=\frac{P_2 V_2}{T_2}\) Constant Temperature (T1 = T2) \(P_1 V_1=P_2 V_2\) Boyle's Law \(\frac{P_1 V_1}{T_1}=\frac{P_2 V_2}{T_2}\) Constant Pressure (P1 = P2) \(\frac{V_1}{T_1}=\frac{V_2}{T_2}\) Charles' Law \(\frac{P_1 V_1}{T_1}=\frac{P_2 V_2}{T_2}\) Constant Volume (V1 = V2) \(\frac{P_1}{T_1}=\frac{P_2}{T_2}\) Gay-Lussac's Law Exercise \(\PageIndex{1}\) You have a sample of gas with a pressure of 1.86 atm, volume of 4.33 L, and temperature of 26.5 °C. If you cool it to 12.7 °C and decrease the volume to 3.45 L, what will the pressure be?. Answer 2.23 atm. Exercise \(\PageIndex{1}\) You have a flexible container of gas with a volume of 5.220 L at 19.4 °C. At what temperature would the volume increase to be 6.000 L? Answer 336.3 K or 63.1 °C.