I. Avogadro

1
Chapter 14-3

• I. Avogadros Principle
• A. Equal volumes of gases at same T and P
  contain equal s of molecules
• B. H2 Cl2 ? 2HCl
• 1 vol. 1 vol. 2 vol.
• 1 molec. 1 molec 2 molec
• 1 mol 1 mol 2 mol

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Chapter 14-4

• II. Molar Volume of Gases
• A. 1 mole 6.022 x 10 23 molecules
• B. STP 22.4L
• C. 1 mol
• 22.4L
• D. 1 cm3 1 mL
• III. Practice problems
• 1. At STP, what is the volume of 7.08 mol of
  nitrogen gas?
• 159 L N2

3

• Practice problems
• 2. At STP, a sample of neon gas occupies 550.
  cm3. How many moles of neon gas does this
  represent?
• .0246 mol Ne
• 3. What is the mass of 1.33 x 104 mL of oxygen
  at STP?
• 19.0 g O2
• 4. What is the volume of 77.0g of nitrogen
  dioxide gas at STP?
• 37.5L NO2

4
Ideal Gas Law

• PV nRT
• R .0821 L x atm/ mol x K
• n of moles of a gas

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Practice problem

1. If the pressure exerted by a gas at 25C in a
   volume of 0.044L is 3.81atm, how many moles of
   gas are present?
2. Calculate the grams of N2 present in a 0.600L
   sample kept at 1.00atm pressure and a temperature
   of 22.0C