PRACTICE AND REVIEW GAS LAWS

STUDENT LEARNING OBJECTIVES 1.Define pressure. Identify units of pressure and make conversions between appropriate pressure units 2.Describe the relationship between pressure and volume of a fixed quantity of a gas. 3.Given a change in volume, determine the resulting change in pressure (and vice versa) 4.Describe the relationship between temperature and volume of a fixed quantity of a gas. 5.Define “absolute zero”. Convert temperatures between Celsius and Kelvin 6.Given a change in temperature, determine the resulting change in volume (and vice versa) 7.Describe the relationship between the volume of a gas and the quantity of the gas (in moles). 8.Given a change in moles, determine the resulting change in volume (and vice versa) 9.Combine Boyles, Charles, and Avogadro’s Laws to form the Ideal Gas Law 10.Use the ideal gas law to determine the result of changing conditions on a sample of a gas 11.Use the ideal gas law to determine the quantity of a gas under a given set of conditions

PRESSURE RESULTS FROM The Number of Molecular Collisions The Energy of Molecular Collisions Which of these is affected by each of the following? A change in the Number of moles of gas A change in Temperature A change in Volume

PRESSURE UNITS Pressure can be expressed in a variety of ways Millimeters of mercury (mmHg) Torr PSI (pounds per square inch) Kilopascals (1000 newtons per square meter) Atmospheres Which unit??? Which two units are derived from force/area? Which two units are 2 names for the same thing Which unit is based on the Barometer? Which unit is based on the average atmospheric pressure at sea level

PRESSURE UNITS Pressure can be expressed in a variety of ways Millimeters of mercury (mmHg) Torr Kilopascals (1000 newtons per square meter) Atmospheres What is the value of standard pressure in each of these units?

PRESSURE UNIT CONVERSIONS Standard Pressure: 760 mm Hg 760 torr kPa 1.00 atm Convert: 800 torr to atm 95 kPa to mmHg 100 kPa to atm.95 atm to mmHg 775 mmHg to atm

PRESSURE VS VOLUME What is the relationship between pressure and volume of a fixed quantity of a gas at a constant temperature? What happens to the pressure with an increase in volume? A decrease in volume? Inverse or Direct proportion?

TEMPERATURE VS VOLUME What is the relationship between the temperature and volume of a fixed quantity of a gas at a constant pressure? What happens to the volume with an increase in temperature? A decrease in temperature? Inverse or Direct proportion?

NUMBER OF MOLES VS VOLUME What is the relationship between the number of moles of a gas and volume (at a constant temperature and pressure) What happens to the volume with an increase in number of moles? A decrease in number of moles? Inverse or Direct proportion?

BOYLES LAW PV = constant P 1 V 1 = P 2 V 2 A syringe contains 25.0 mL of air at 1.0 atm. What will the pressure be if the syringe is compressed to 10.0 mL?

CHARLES LAW V/T = constant V 2 T 1 = V 1 T 2 0 o C = 273 K To convert celsius to kelvin, just add 273 All gas law problems must use kelvin temperature A birthday helium balloon has a volume of 3.5L at 24 o C. What will its volume become if you take it outside on a winter day with a temperature of -6 o C?

AVOGADROS LAW Equal volumes of gases contain an equal number of moles (assuming temperature and pressure are constant) V/n = constant V 2 n 1 = V 1 n mole of nitrogen gas occupies 22.4 L. How many moles of nitrogen gase occupy L? How many moles of Argon gase will occupy 100.0L? How many moles of Oxygen gas will occupy L?

IDEAL GAS LAW PV = nRT P = pressure V = volume (L) n = number of moles R =.0821 atm*L/mol*K T = absolute temp (K) Determine the pressure exerted by.25 mol of air in a 3.0L container at 27 o C Determine the volume of.50 mol of air at 20 o C and 1.1 atm

STANDARD TEMPERATURE AND PRESSURE Standard temperature = 0 o C Standard temperature = 273 K Standard pressure = 1.00 atm At STP, one mole of any gas will occupy 22.4 L This is called Standard Molar Volume

STANDARD TEMPERATURE AND PRESSURE Determine the volume of4.0 moles of air at STP How many moles will occupy 50.0 L at STP? At STP, one mole of any gas will occupy 22.4 L This is called Standard Molar Volume