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Mass-Gas Stoichiometry. Using a balanced chemical equation, it is possible to determine the volume of a gas if the mass of a reactant or product Is given. This mass-volume stoichiometry. Mass-Gas Stoichiometry. In mass-volume stoichiometry it is
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Mass-Gas Stoichiometry Using a balanced chemical equation, it is possible to determine the volume of a gas if the mass of a reactant or product Is given. This mass-volume stoichiometry.
Mass-Gas Stoichiometry In mass-volume stoichiometry it is Necessary to use the molar volume of a gas. One mole of any gas at STP (Standard Temperature and Pressure, 101.3 kPa and 273 K) occupies a volume of 22.4 L. So You will use 1 mole = 22.4 L as your last conversion unit instead of the formula mass.
Sample Problem: How many liters (at STP) of carbon dioxide, CO2, will be produced in the following reaction if 3.59 g of oxygen, O2, is consumed during combustion of octane, C8H18? 3.59 g ? 2 25 16 18 C8H18 + O2→ CO2 + H2O Step 1: Balance the chemical equation
3.59 g? 2C8H18+ 25O2→ 16CO2+ 18H2O Step 2: Convert grams of given substance to moles 3.59 g O2 1 mol O2 32.0 g O2 16 mol CO2 25 mol O2 22.4 L CO2 1 mol CO2 = 1.61 L CO2 Step 3: Give ratio of moles required gas/moles of given substance Step 4: Convert moles of required gas to liters Step 5: Cancel and solve
Practice problems Try to work the next problems on the paper first. Then use the power point to check your work.
Practice Problem 1: What volume of oxygen (O2) at STP is produced during the electrolysis of 10.0 g H2O in the equation given below? 10.0 g? H2O H2+ O2 2 2 Solve the above problem and check your answer below: 10.0 g H2O 1 mol H2O 18.0 g H2O 1 mol O2 2 mol H2O 22.4 L O2 1 mol O2 = 6.22 L O2
Practice Problem 2: What is the volume of chlorine at STP released during the following reaction by 3.88 grams of barium chloride assuming an excess of bromine (Br2)? 3.88g ? BaCl2+ Br2 BaBr2 + Cl2 Solve the problem and then check your answer below. 3.88 g BaCl21 mol BaCl2 208 g BaCl22 1 mol Cl2 _ 1 mol BaCl2 22.4 L Cl2 1 mol Cl2 = 0.418 L Cl2
Practice Problem 3: What volume of ammonia (NH3) at STP will be produced by 32.0 grams of hydrogen (H2) reacting with an excess of nitrogen (N2) in the following reaction? 32.0 ? H2+ N2 NH3 3 2 Solve the problem and then check your answer below. 2 mol NH3 3 mol H2 32.0 g H21 mol H2 2.02 g H2 22.4 L NH3 1 mol NH3 = 237 L NH3