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CHAPTER 14. Gases. 14.3 Stoichiometry and Gases. Draw me. Ideal gas law. Me too! Me too!. We can now solve stoichiometry puzzles involving gases. R = universal gas constant. We can now solve stoichiometry puzzles involving gases. with 1. solids 2. solutions 3. other gases.
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CHAPTER 14 Gases 14.3 Stoichiometry and Gases
Draw me. Ideal gas law Me too! Me too! We can now solve stoichiometry puzzles involving gases R = universal gas constant
We can now solve stoichiometry puzzles involving gases with 1. solids 2. solutions 3. other gases
Ideal gas law We can now solve stoichiometry problems involving gases and solids solutions other gases R = universal gas law
Stoichiometry Puzzle #1 of 3 Limiting reactant is a solid: If you burn a 125 g candle made of paraffin wax, the peak temperature of the flame is about 1,400oC. Assuming the carbon dioxide produced is at that temperature, what volume of CO2 is produced at a pressure of 790 mmHg? The combustion reaction is: 2C20H42 + 61O2→ 40CO2 + 42H2O
If you burn a 125 g candle made of paraffin wax, the peak temperature of the flame is about 1,400oC. Assuming the carbon dioxide produced is at that temperature, what volume of CO2 is produced at a pressure of 790 mmHg? The combustion reaction is: 2C20H42 + 61O2→ 40CO2 + 42H2O Asked:Volume of CO2 produced Given: Paraffin: mass of 125 g CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 125 g C20H42
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 0.442 moles C20H42 125 g C20H42
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 0.442 moles C20H42
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 0.442 moles C20H42 8.85 moles CO2
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 8.85 moles CO2
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 8.85 moles CO2
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 8.85 moles CO2
Asked: Volume of CO2 produced Given: Paraffin: mass of 125 g; CO2: P = 790 mmHg, T = 1,400oC Relationships: Molar mass of paraffin = 282.6 g/mole Mole ratio: 2 moles C20H42 ~ 40 moles CO2 PV = nRT Solve: 8.85 moles CO2 1,170 L CO2
Ideal gas law We can now solve stoichiometry problems involving gases and solids solutions other gases R = universal gas law
Stoichiometry Puzzle #2 of 3 Limiting reactant is a solution: A common reaction occurs when an acid reacts with a metal to produce hydrogen gas. Consider a reaction in which 0.050 L of 1.25 M hydrochloric acid reacts with excess magnesium: If the gas produced is captured in a 1.00 L container that starts out empty, what will be the pressure at the end of the reaction when the gas has cooled to 22oC? Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq)
A common reaction occurs when an acid reacts with a metal to produce hydrogen gas. Consider a reaction in which 0.050 L of 1.25 M hydrochloric acid reacts with excess magnesium: If the gas produced is captured in a 1.00 L container that starts out empty, what will be the pressure at the end of the reaction when the gas has cooled to 22oC? Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) Asked:Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT
Volume Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.050 L HCl 1.25 M HCl
Volume Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.050 L HCl 1.25 M HCl 0.0625 moles HCl
Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.0625 moles HCl
Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.0625 moles HCl 0.0313 moles H2
Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.0313 moles H2
Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.0313 moles H2
Asked: Pressure of H2 produced Given: HCl: V = 0.050 L, Molarity = 1.25 moles/L H2: V = 1.00 L, T = 22oC Relationships: Mole ratio: 2 moles HCl ~ 1 mole H2 PV = nRT Solve: 0.0313 moles H2 0.756 atm H2
Ideal gas law We can now solve stoichiometry problems involving gases and solids solutions other gases R = universal gas law
Stoichiometry Puzzle #3 of 3 Limiting reactant is a gas: What volume of butane gas is needed at room temperature (23oC) and typical pressure (0.954 atm) to produce 85.0 L of carbon dioxide at 825oC and a pressure of 1.04 atm? The reaction is: 2 C4H10(g) + 13 O2(g) → 8 CO2(g) + 10 H2O(g)
What volume of butane gas is needed at room temperature (23oC) and typical pressure (0.954 atm) to produce 85.0 L of carbon dioxide at 825oC and a pressure of 1.04 atm? The reaction is: 2C4H10(g) + 13O2(g) → 8CO2(g) + 10H2O(g) Asked:Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve: C4H10 CO2
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve: C4H10 CO2
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve: C4H10 CO2 Use the mole ratio to substitute for nCO2
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve:
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve:
Asked: Volume of C4H10 needed to produce 85.0 L of CO2 Given: C4H10: P = 0.984 atm, T = 23oC CO2: P = 1.04 atm, T = 825oC, V = 85.0 L Relationships: Mole ratio: 2 moles C4H10 ~ 8 moles CO2 Solve:
Ideal gas law We have now solved stoichiometry problems involving gases and solids solutions other gases R = universal gas law