gas stoich lecture 3 gas stoichiometry. ways we’ve already gotten in/out of moles grams moles can...
TRANSCRIPT
![Page 1: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/1.jpg)
Gas Stoich Lecture 3Gas Stoichiometry
![Page 2: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/2.jpg)
Ways We’ve Already Gotten In/Out of Moles
• Grams Moles• Can use the molar mass of the compound to do that
• Liters Moles• Can use molarity equation to solve for moles (into moles),
or solve for volume/molarity (out of moles)
![Page 3: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/3.jpg)
Gas Stoichiometry
• Can now use the ideal gas law to get into/out of moles
• Into moles: PV = nRT
Can use gas information to solve for moles
![Page 4: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/4.jpg)
Gas Stoichiometry
• Can now use the ideal gas law to get into/out of moles
• Out of moles: PV = nRT
After doing the mole ratio, can solve for a quantity of gas
![Page 5: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/5.jpg)
Gas Stoichiometry• STP: 0°C and 1 atm = 760 mm Hg = 101.3 kPa
• If you are at STP (and ONLY if you are at STP) –• 1 mole = 22.4 L• Can use as a way to get in and out of moles too!
![Page 6: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/6.jpg)
Same Steps for Stoichiometry
1. Get it into moles
2. Do the mole ratio
3. Get it out of moles
![Page 7: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/7.jpg)
Gas Stoich Example 1 - together• Sodium bicarbonate is heated.
• How many grams of carbon dioxide are produced if 2.76 grams of solid sodium bicarbonate are heated?
![Page 8: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/8.jpg)
Gas Stoich Example 2 – on your own• Sodium metal is added to water.
• If 43.2 mL of hydrogen gas are produced at 767 torr and 59°C in excess water, how many grams of sodium were reacted?
![Page 9: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/9.jpg)
Gas Stoichiometry
• All of stoichiometry still in play!• Limiting reactants
• Excess reactants
• Theoretical yields
• Percent yield
• Using gas stoich to find % composition in unknown
• Etc……..
![Page 10: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/10.jpg)
Gas Stoich Example 3 – A bit more complicated….
• Acetic acid reacts with solid sodium carbonate.
• 5.00 grams of sodium carbonate is added to 20.0 mL of 1.50 M acetic acid. What volume of CO2 is produced at 0.878 atm and 23°C?
![Page 11: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/11.jpg)
Dalton Law of Partial Pressures
Ptotal = P1 + P2 + P3 +….
• The total pressure = the sum of all the partial pressures
We’ll do more with this later in the unit, just one application for now….
![Page 12: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/12.jpg)
Application of Dalton’s Law of Partial Pressures
HUGE!
Collecting pressure over water
Pair
Pgas PH2O vapor
![Page 13: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/13.jpg)
Application of Dalton’s Law of Partial Pressures• Collecting pressure over water
• Because the water level is equal, we can assume pressure inside is EQUAL to the pressure outside
• So …… Pair = Pgas + PH2O vapor solve for Pgas
• PH2O is temperature dependent can look up on chart
• Pair is barometric pressure can look up on weather station
Pair
Pgas PH2O vapor
![Page 14: Gas Stoich Lecture 3 Gas Stoichiometry. Ways We’ve Already Gotten In/Out of Moles Grams Moles Can use the molar mass of the compound to do that Liters](https://reader035.vdocuments.mx/reader035/viewer/2022062300/56649e635503460f94b5fb2e/html5/thumbnails/14.jpg)
Gas Stoichiometry Demo• Magnesium and hydrochloric acid……