1. Molecular Composition of Gases The Ideal Gas Law

2. Objectives: 1.State the ideal gas equation. 2.Derive the ideal gas constant and state its units. 3.Use the ideal gas equation to calculate the amount of gas at any condition of temperature and pressure. 4.Use the ideal gas equation to calculate the molar mass of a gas given its density. 5.Reduce the ideal gas law to Boyle’s, Charles’, Gay- Lussac’s, or Avogadro’s Law.

3. The Ideal Gas Law Mathematical relationship between pressure, volume, temperature, and the number of moles of gas.

4. Ideal Gas Law Calculate the value of R for 1 mole of gas at STP. The value of “R” depends on the units used for P, V, and T. The ideal gas law can be reduced to any of the previously studied gas laws when certain variables are held constant.

6. Sample Problems 1.A 2.07 L cylinder contains 2.88 mol of helium gas at 22 o C. What is the pressure in atmospheres of the gas in the cylinder? 2.A tank of hydrogen gas has a volume of 22.9 L and holds 14.0 mol of the gas at 12 o C. What is the reading on the pressure gauge in atmospheres? 3.A reaction yields 0.00856 mol of O 2 gas. What volume will this occupy if it is collected at 43 o C and 0.926 atm pressure? 4.What mass of ethene gas, C 2 H 4 is contained in a 15.0 L tank that has a pressure of 4.40 atm at a temperature of 305 K?

7. Ideal Gas Law and Molar Mass A chemist determines the mass of a sample of gas to be 3.17 g. Its volume is 942 mL at a temperature of 14 o C and a pressure of 1.09 atm. What is the molar mass of the gas.

8. Ideal Gas Law and Molar Mass

9. Ideal Gas Law and Density Knowing that density is mass/volume, what is the density of a sample of ammonia, if the pressure is 0.928 atm and the temperature is 63.0 o C?

10. Ideal Gas Law and Density