Conceptual Examples and Concepts Basic Problem Solving Gas Laws Conceptual Examples and Concepts Basic Problem Solving

Remember back 5 rows of even side are no seating zones Please turn off all downloads. You can usually pause them by clicking on them and clicking pause. Facebook and youtube are officially banned during class time (this is not me micromanaging, it’s a legit internet issue as told to me by OIT). Visit: https://checkin.ics.uci.edu/ Log in and select Chem 1A. When prompted, type the word of the day: boyles Ensure when asked if you will share your location you select “allow”. Visit: https://learningcatalytics.com/ Sign in MasteringChemistry account name When prompted, type session ID: Remember back 5 rows of even side are no seating zones Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Examples: Avogadro's Law If you double the number of moles in a container while holding temperature and pressure constant, what happens to the volume? Both balloon and two breaths And solid CO2 and bottle. doubles Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Examples: Avogadro’s Law If you halve the number of moles in a container while holding temperature and volume constant, what happens to the pressure? halves Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Examples: Boyles If you double the size of a container while holding temperature and moles constant, what happens to the pressure? halves 2 atm 1 atm Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Examples: Charles Law If you halve the temperature while holding moles and pressure constant. What happens to the volume? halves Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Examples: Charles Law If you halve the temperature while holding moles and volume constant. What happens to the pressure? halves Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

so total pressure quadrupled (x4) For each of the following situations, state whether the stated variable would increase or decrease, and if possible by how much. (Assume anything not mentioned is held constant.) Temperature (kelvin) doubles, volume is halved. What happens to pressure? Temperature (kelvin) doubles, volume is doubled. What happens to pressure? Temp  pressure x2, Volume pressure x2, so total pressure quadrupled (x4) Temp  pressure x2, Volume pressure divided by 2, so total stays the same Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Pressure  temp divided by 3 So temp  stays the same For each of the following situations, state whether the stated variable would increase or decrease, and if possible by how much. (Assume anything not mentioned is held constant.) Volume doubles, pressure doubles. What happens to temperature? Volume triples, pressure is decreased to 1/3 of its original. What happens to temperature? Temperature is doubled and half of the gas is removed? What happens to pressure? Volume  temp x2 Pressure  temp x2 So temp  x4 Volume  temp x3 Pressure  temp divided by 3 So temp  stays the same Temp  pressure x2 n  pressure divided by 2 So pressure  stays the same Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems Hints: Explain why rapid changes in altitudes cause ear pain? Hints: What is the pressure like at high altitudes? What does the pressure difference put pressure on (use picture  )? Which way does it bulge? How does this change if instead of altitude change you go underwater? Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems Explain why rapid changes in altitudes cause ear pain? What is the pressure like at high altitudes? Low pressure What does the pressure difference put pressure on (use picture  )? Which way does it bulge? Outside is lower so pressure will make it bulge out How does this change if instead of altitude change you go underwater? Outside pressure would be higher than inside so it would bulge in, but still cause pain. Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems (this will allow some troubleshooting when you start gas calculation problems.) Explain why scuba divers must not hold their breath while coming to the surface? Hints: When at the bottom of a dive is the pressure low or high? As the diver comes up, what happens to the pressure? What happens to the volume of the air in their lungs as this happens? Why is this bad? Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems (this will allow some troubleshooting when you start gas calculation problems.) Explain why scuba divers must not hold their breath while coming to the surface? When at the bottom of a dive is the pressure low or high? High As the diver comes up, what happens to the pressure? decreases What happens to the volume of the air in their lungs as this happens? Expands Why is this bad? The lungs will burst. Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems (this will allow some troubleshooting when you start gas calculation problems.) If a gas is collected over water is that gas pure (see picture)? Hints: What does water do on a hot surface, think a puddle on a warm day? Does this only happen on hot surfaces or everywhere? What about in enclosed areas? How does this effect what is in the space above the water? Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Conceptual Problems (this will allow some troubleshooting when you start gas calculation problems.) If a gas is collected over water is that gas pure (see picture)? What does water do on a hot surface, think a puddle on a warm day? Evaporate Does this only happen on hot surfaces or everywhere? Everywhere What about in enclosed areas? Yup How does this effect what is in the space above the water? Has both the collected gas and water vapor. Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Review Questions (things you’ll need to remember for gas Problems) Be sure to review, stoichiometry, empirical formulas, and balancing chemical reactions Chapters 5 and 8. If you didn’t learn this the first time around you’ll start to run into problems in this section. Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Review Questions The empirical formula of a species is CH2. Its molecular mass is 84 g/mol. What is its molecular formula? CH2 =12+1+1=14g/mol 84/14=6 C6H12 Visit: https://checkin.ics.uci.edu/ Word of the day: boyles LearningCatalytics: session ID:29436506

Challenge Question

With hindsight, Harrison Okene probably should have seen the signs With hindsight, Harrison Okene probably should have seen the signs. All of the ingredients were in place: He was young, happy, and gainfully employed as a cook on a Chevron service tugboat. Also, he was about to get married in a few days. All he had to do before his wedding was finish this one ... last ... mission. Of course, said mission turned into the most terrifying disaster movie this side of the SS Poseidon. In the early morning of May 26, 2013, Okene had just gotten up and was in the bathroom. Suddenly, his ship was hit by what a spokesman later called a "sudden ocean swell" (which is presumably corporate speak for "Shit, we accidentally summoned Cthulhu again"). Okene could only watch helplessly as his daily life turned into a trip to Rapture. The tugboat capsized and plummeted 100 feet below the surface, with him still inside. Trapped in the dark abyss with no one else in sight and wearing nothing but his boxers, Okene waded through the ship's corridors (which were slowly filling with icy water). He managed to locate a source of light, some Coca-Cola, and a few tools, and he made it to a relatively safe corner of the ship. Okene ended up bunking in a 4-foot air pocket under the surface, holding back the water as best he could and stacking mattresses as the cold water rose to keep dry. To make things worse, sharks and barracudas soon started roaming the ship's interiors in search of a meal. He could hear them fighting for the remains of his shipmates in other rooms and swimming in the water just below him. He had no food. The salt water and the bumps from the accident were wearing his skin raw. There was far too little air for him to breathe, and he was ruining it with every breath by puffing out carbon dioxide. He would not last beyond a couple of hours. Except that he totally did. In fact, he managed to stay alive for 62 hours. Here's how……. ****Exerpt taken from Cracked.com “Survival stories almost too miraculous to be real”****

Theoretically how could he have survived? We won’t do the math, we’ll just talk though it in concept. Challenge question: Do the math (you’ll need the ideal gass law, PV=nRT) and see what happens. State all assumptions you make. I’ll post my results online and link to some people who did it other ways.