SCH3U - Chemistry Gases Test

SCH3U Grade 11 Chemistry Gases Test Background of Gases ○ Kinetic Molecular Theory: In terms of random motion with no volume and no attractive forces, gas behavior is explained. ○ UP temperature -> breaks bonds faster -> transforming states Spaces Attraction Motion Type Shape Volume Solid Very tight Strong Vibrational Fixed Fixed Liquid Further Apart Somewhat Translational, rotational, vibrational Container Fixed Gas Very far apart Weak Rotational, translational, vibrational Container Changes ● Pressures ○ SI Unit = 1 Pascals (Pa) or Kilopascals (KPa) ○ Older units: torr = 1 mm of Hg ○ STP = 760 mm Hg = 760 torr = 1 atm = 100.3 KPa ○ SATP = 250C at 100 KPa ● Temperature ○ Normally in Degrees Celsius, but may have to convert to Kelvin ○ 1 Kelvin = -273.150C ○ Convert C to K -> + 273.15 ○ Convert K to C -> – 273.15 ● Gas Laws ○ Boyle’s Law ■ Pressure UP = Volume DOWN ■ P1*V1 = P2*V2 ● Charles’ Law ○ Temperature UP = Volume UP ○ V1/T1 = V2/T2 ● Gay-Lussac’s Law ; ○ Temperature UP = Pressure UP ○ P1/T1 = P2/T2 ○ Combined Gas Law ■ Accounts for pressure, temperature, and volume changes ■ (P1*V1)/T1 = (P2*V2)/T2 ■ Ideal Gas Law properties ■ Elastic collisions ■ Point mass and no volume ■ No forces of attraction

■ Do not condense to liquid ■ Dalton’s Law of partial pressure ■ A pressure that a gas in amixture would exert if it was the only gas present in the same volume and same pressure ■ Ptotal=P1+P2+P3…+Pn ■ Molar Volume ■ Volume or amount of space that 1mole occupies at specific T and P ■ Vm=V/n ■ Vm = molar volume ■ V = Volume (in L) ■ n = # of moles ● Molar volume of ideal gas at: ○ STP: 22.6L/Mol ○ SATP(SAP): 24.8L/Mol ○ Avogadro’s Law ■ States that ALL ideal gasses at the same temperature and pressure contains the same number of molecules of gasses ■ n1/V1=n2/V2 ■ Ideal Gas Law ■ PV = nRT ■ Where R is the universal constant of gasses 8.314 ■ Temperature always in K ■ Volumes in L ■ Pressure in KPa usually recommended ● Deriving Ideal gas law ○ Molar Mass ■ mRT/PV = M (g/mol) ■ Density ■ m/v = MP/RT (g/L) ■ Molar Concentration ■ C = n/V = P/RT (mol/L) ■ Pressure of Water Vapors ■ Pdry gas= Patm – Pwatervapour ■ Pressure of water vapor obtained with a table that relates it to temperature ■ Gas Stoichiometry 1. Balancing Equation 2. Convert everything to moles (from formulas etc.) 3. Mole to mole ratio 4. Solve for your unknown

● Must find limiting reactant if necessary ● Volume to Volume: nothing to do since volume = number of moles