Simple Gas Laws PDF

Chemistry Unit 2 Simple Gas Laws Lesson 2 Table of contents 01 02 03 Simple Gas Boyle’s Law Charles’ Law Laws 0 05 4...

Chemistry Unit 2 Simple Gas Laws Lesson 2 Table of contents 01 02 03 Simple Gas Boyle’s Law Charles’ Law Laws 0 05 4 Gay Lussac's Avogadro’s Law Law  01 Simple Gas Laws  Simple Gas Laws Based on the KMT of gases, scientists were able to describe how gases behave and change using mathematical equations. There are 4 variables that describe gases: Volume Absolute temperature (in K) Pressure number of moles Simple gas laws show relationship between two variables while the other two are held constant  STP and SATP Standards for Gas Laws:  Temperature For gas laws, temperature MUST be in Kelvin, K o T= C + 273.15 Depending on the significant figures of the thermometer reading, the decimals may be needed.  02 Boyle’s Law Boyle’s Law Relationship between pressure and volume Boyle’s Law ○ At a constant temperature, the volume occupied by a given quantity of gas is inversely proportional to the pressure of the gas ○ As volume increases ↑, pressure decreases ↓ ○ As volume decreases ↓, pressure increases ↑ Boyle’s Law Boyle’s Law  Question A 2.50 L sample of helium gas is collected at STP in a balloon. The pressure on the balloon is then increased to 110.6 kPa, what is the new volume? 03 Charles’ Law Charles’ Law Relationship between volume and temperature Charles’ Law ○ At a constant pressure the volume occupied by a given quantity of gas is directly proportional to its absolute temperature (Kelvin temperature = oC + 273) ○ As a gas is heated, volume increases ↑ ○ As a gas is cooled, volume decreases ↓ Charles’ Law Charles’ Law  Question A 28.7 mL sample of gas is collected at SATP. It’s temperature is then increased to 65 oC. If the pressure is held constant, what is the new volume?  04 Gay Lussac’s Law  Gay Lussac’s Law Relates pressure and temperature Gay Lussac’s Law At a constant volume, the pressure of a given quantity of as is directly proportional to the absolute temperature (K) As the temperature increases, there are more frequent collisions with the walls of the container = an increase in pressure Gay Lussac’s Law Gay Lussac’s Law Gay Lussac’s Law  Question At 14.0 oC carbon dioxide gas is stored in a metal tank at a pressure of 507 kPa. What will the new pressure be if the temperature is increased to 40.0 oC?  05 Avogadro’s Law  Avogadro’s Law Relates the number of moles to the volume Avogadro's Law Under the same temperature and pressure, the volume of a gas is directly proportional to its quantity in moles(n) This means that at the same temperature and pressure, equal volumes of gas contain the same number of moles Avogadro’s Law Avogadro’s Law  Question A helium balloon occupies a volume of 15.0 L when filled with 0.50 moles of gas at SATP. What will the new volume be if 0.20 moles of helium gas are added under the same conditions?  Molar Volume of a Gas An extension of Avogadro’s Law Molar volume (Vm) indicates the volume of a gas occupied by one mole of that gas under fixed conditions of temperature and pressure. The units are L/mol Avogadro’s Law determined the MOLAR VOLUME of any gas, basically his theory states: ** Volume of 1 mol of a gas at STP = 22.4 L ** ** Volume of 1 mol of a gas at SATP = 24.5L ** Molar Volume of a Gas Molar Volume of a Gas  Question Suppose that you have 69.2 L of methane gas at STP. How many moles are present?