University:
High School
Course:
High School Physics
Academic year:

2020
Views:

250

Pages:

8
Author:

Krista Conley

Combined Gas Law: a combination of Boyle's and Charles' Law that allows all 3 variables (P, V, T) to be considered at the same time [\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}] Table T 1. 48.0 Liters of gas are collected at STP. What will the new volume of the gas if the temperature is changed to 273 °C and 1.50 atmospheres? [V_{1}=48.0L] [P_{1}=1.0atm] [T_{1}=273K] [P_{2}=1.50atm] [T_{2}=546K] [\frac{1.0\times48.0}{273}=\frac{1.5\times V_{2}}{546}] [V_{2}\times409.5=76708] [V_{2}=64L] 2. 6.0 L of a gas is collected at 101.3 kPa and 37°C. When the pressure is increased to 202.6 kPa the volume increases to 8.4 L. What is the new temperature in Kelvin and Celsius? [V_{1}=6.0L] [P_{1}=101.3kPa] [T_{1}=310K] [V_{2}=8.4L] [P_{2}=202.6kPa] [T_{2}=?] [\frac{101.3\times6.0}{310}=\frac{202.6\times8.4}{T_{2}}] [T_{2}\times607.8=527570.4] [T_{2}=868K] [T_{2}=595°C] 3. 1.0 L of a gas was collected at STP. What would be the pressure of the gas if the temperature was raised to 100°C and the volume was increased to 2.0 L? [1.0atm\times1.0=P_{2}\times2.0] [P_{2}=.68atm] [P_{2}=546torr] [P_{2}=519.2torr] Law of Diffusion: Read p.436 to find the definition The rate of diffusion of a gas is inversely proportional to the square root of the gas's density. Small Gas - Fast Large Gas - Slow How does mass affect the rate of diffusion: Describe what happens to entropy during diffusion: Gases spread out + entropy increases. Circle the gas that will diffuse at the fastest rate under the same conditions of T and P: H₂ or He N₂ or Cl₂ Ne or Ar O₂ or NH₃ p.422-13 COMBINED GAS LAW In practical terms, it is often difficult to hold any of the variables constant. When there is a change in pressure, volume and temperature, the combined gas law is used. 1 [\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}] or [P_{1}V_{1}T_{2}=P_{2}V_{2}T_{1}] Complete the following chart. P₁ V₁ T₁ P₂ V₂ T₂ 1 1.5 atm 3.0 L 20 °C 2.5 atm 1.86 L 30 °C 293 K 303 K 2 101.3 kPa 256 mL 25 °C 112.4 kPa 250 mL 50 °C 298 K 323 K 3 600 mmHg 2.5 L 22 °C 760 mmHg 1.8 L 26.9 °C 295 K 299.9 K 4 1.22 atm 750 mL 0.0 °C 2.0 atm 500 mL 25 °C 273 K 298 K 5 95 kPa 4.0 L 25 °C 101 kPa 6.0 L 198 °C 298 K 471 K 6 101.3 kPa 591.8 mL 100 °C 202.6 kPa 225 mL 150 °C 373 K 423 K 7 2.5 atm 1.5 L 15 °C 1.58 atm 2.5 L 30 °C 288 K 303 K 8 125 kPa 125 mL 544 K 100 kPa 100 mL 75 °C 348 K