Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Catalytic reforming wikipedia , lookup
Particle-size distribution wikipedia , lookup
History of manufactured fuel gases wikipedia , lookup
Electrolysis of water wikipedia , lookup
Diamond anvil cell wikipedia , lookup
Gas chromatography–mass spectrometry wikipedia , lookup
Aliso Canyon gas leak wikipedia , lookup
Atomic theory wikipedia , lookup
Size-exclusion chromatography wikipedia , lookup
Gas chromatography wikipedia , lookup
CHAPTER 12: GAS LAWS, GAS MIXTURES, AND GAS REACTIONS 12.1 AVOGADRO’S LAW AND MOLAR VOLUME GAY-LUSSAC’S LAW OF COMBINING VOLUMES When gases react, volumes of gaseous reactants and products of chemical reaction (at equal temperatures and pressures) are in simple whole number ratios. Example: When hydrogen and oxygen come together to produce water, 2 unit volumes of hydrogen and 1 unit volume of oxygen results in 2 unit volumes of water. Mole Ratio Volume Ratio 2 H2 2 mol 2 vol units + O2 2 H2O : 1 mol : 2 mol : 1 vol units : 2 vol units AVOGADRO’S LAW Equal volumes of gases at the same temperature and pressure contain an equal number of molecules. Consider the following example: A container with 1.0 L of H2 at STP has the same number of molecules as a container with 1.0 L of N2 at STP, even though the mass of nitrogen is 14 times greater. The pressure is directly related to the number of particles in each container of gas. So if each container had the same amount of pressure, there would be no difference in the number of particles. Mathematically, nV or n = kV or n1 = n2 V1 V2 Sample Problem 1: A balloon contains 2.0 L of helium gas at STP. How many moles of helium are present? G: n1 = 1.00 mol V1 = 22.4 L V2 = 2.0 L R: n2 = ? A: n1 = n2 V1 V2 n2 = n1 x V2 V1 S: n2 = (1.00 mol)(2.0 L) / (22.4 L) = 0.089 mol S: Therefore, 0.089 mol He are present. Sample Problem 2: A balloon with a volume of 34.5 L is filled with 3.2 mol of helium gas. To what volume will the balloon expand if another 8.0 g of helium is added? MOLAR VOLUME Molar Volume is the volume occupied by one mole of a gas. It is the same value for all gases. The molar volume for a gas a STP is 22.4 L. The molar volume of a gas at SATP is 24.8 L. Therefore at STP 1 mol = 22.4 L and at SATP 1 mol = 24.8 L Sample Problem 3: A sample of helium at SATP has a mass of 32.0 g. What volume does this mass of gas occupy? Read Page 576-581 and Do questions 1-2, 3ace, 4, 6