Ask your partner… “How many of the ABC’s of Chemistry do you know?” CHEMISTRY! Turn in GL Lab on Google Classroom now! Have your notebook open to the warm-up section of your notebook Have your HW Sheet out and your HW! Ask your partner… “How many of the ABC’s of Chemistry do you know?”

Warm-up A 2.0 liter tank of oxygen gas is at a pressure of 3.5 atm. What volume of oxygen will be available if the oxygen is used at a pressure of 752 mm Hg?

ANSWERS A. A 2.0 liter tank of oxygen gas is at a pressure of 3.5 atm. What volume of oxygen will be available if the oxygen is used at a pressure of 752 mm Hg?

Learning Targets

Scientific Explanations Claim  A simple statement that clearly identifies the outcome (often the relationship between variables) Evidence  Data that is appropriate and sufficient to support the claim Reasoning  Justification that links the claim and evidence  Shows why by using scientific concepts (like definitions, models, theories, or laws) and background knowledge  Often refers to resources such as lab books, articles, textbooks, and/or the Internet

Boyle’s Law Explanation Given a closed system in which the temperature stays the same, explain the relationship between pressure and volume of a gas. (Your claim should include a mathematical equation that demonstrates this relationship).

Boyle’s Law Explanation Given a closed system in which the temperature stays the same, explain the relationship between pressure and volume of a gas. (Your claim should include a mathematical equation that demonstrates this relationship). Claim: Given a closed system in which temperature stays the same, the relationship between pressure and volume in an inverse relationship, PV=k. What do we like about this claim?

Boyle’s Law Explanation Given a closed system in which the temperature stays the same, explain the relationship between pressure and volume of a gas. (Your claim should include a mathematical equation that demonstrates this relationship). Evidence: In the Boyle’s Law Lab that we did in class, the graph of pressure (kPa) and volume (mL) resulted in an inverse relationship What do we like about this evidence?

Boyle’s Law Explanation Reasoning: The graph shows that as pressure increases as volume decreases. When volume decreases the particles have less space to fly around and therefore hit each other and the walls of their container more often. More collisions between the particles hitting each other and the walls of the container cause the pressure to increase as the volume decreases, thus having an indirect relationship What do we like about this reasoning?

Breaking Down Gay-Lussac’s Law

Pressure vs. Temperature – Gay Lussac’s Law Pressure (kPa) Temperature (K) Constant k (P / T ) (PT)

Absolute Zero on a Celsius Graph When pressure increases, what happens to the temperature? Why do you think that happens? What type of relationship is that? What mathematical relationship? Where does the line cross the y- axis? What does that mean when line crosses the y-axis? What would it take to have zero pressure? Do you think that is possible?

Gay-Lussac’s Law If P/T = constant (k), then… P 1 /T 1 =k= P 2 /T 2 P 1 /T 1 = P 2 /T 2  P units don’t matter if same on both sides; but… Temperature MUST BE IN KELVIN! °C +273 = K K – 273 = °C

 Heat something = Add Energy to Atoms  Atoms move ____________!  Cool something = Removing Energy to atoms  Atoms move _____________!  You can keep adding Energy, but there is only so much you can take away!!! Cold  Limit to how “Cold” something can be. ABSOLUTE ZERO  -273°C or 0 K Standard Temperature = 0°C Temperature & Absolute Zero FASTER SLOWER

Pressure vs. Temperature P/T or P ∙ T If P increases, what happens to T? Direct or Indirect Mathematical Relationship? Which gas law variables are being held constant? How did you keep them constant in the lab?  P/T  If P increases, T increases  Direct Relationship  Same Volume and Same Moles  The air in the flask had the same volume and amount of moles the whole experiment

Gay-Lussac’s Practice

Gay-Lussac Practice Problem A basketball that has a pressure of 22 lb/in 2 is left outside at a temperature of 10.°C. Over night the temperature drops to -10.°C. Will the basketball’s pressure decrease or increase? Explain why your answer makes sense. IMPORTANT!! Anytime temperature is in a gas law you must convert it to KELVIN! What will be the new pressure of the basketball?

Consider this scenario … A basketball that has a pressure of 22 lb/in 2 is left outside at a temperature of 10.°C. Over night the temperature drops to -10.°C. Will the basketball’s pressure decrease or increase? Explain why your answer makes sense. What will be the new pressure of the basketball? P 1 /T 1 = P 2 /T 2 P 1 T 1 P 2 T 2 P 1 =22 lb/in 2 T 1 = 283K P 2 = ???? T 2 =263K (22 lb/in 2 )/283 K = P 2 /263 K P 2 = 20. lb/in 2

See if you can explain these … Why do fish who live in the deep sea die when brought to the surface? Why aren’t the compressed oxygen cylinders on the space shuttle completely filled before launch?

See if you can explain these … Why does cooking at high altitudes (i.e. Colorado) require more time than cooking at lower altitudes (i.e. Seattle)? Why do fish who live in the deep sea die when brought to the surface? Why will the tire gauge pressure for your car tires have a higher reading after your car has been driven for awhile? Why will a limp helium balloon be brought to life at a florist shop with just a hair dryer? Why does the plunger on a turkey syringe thermometer pop out when the turkey is done? Why aren’t the compressed oxygen cylinders on the space shuttle completely filled before launch? Why do you have to use Kelvin instead of Celsius in a gas law equation?

EXIT TASK On a separate piece of notebook paper please write your name on the very top right corner. Given a closed system in which the volume stays the same, explain the relationship between pressure and temperature of a gas. (Your claim should include a mathematical equation that demonstrates this relationship). *Remember to have use claim, evidence, and reasoning! Homework: #7-10 BGC W.S

Peer grade You will be peer scoring 2 papers today. You will not know who you are scoring or who is scoring you. Write your ID# and the student ID# of the paper you are grading on the rubric paper clipped to the paper. Take 5 minutes and thoughtfully read through that paper and grade their Claim, Evidence, and Reasoning. Write WHY you gave them that score.  Be short and to the point! Once you are done, trade with someone around you and repeat!

Once you have finished your 2 nd Peer grade… Please put all papers (paper clipped together) on the lab station near the fume hood. Find your paper and read the scores and comments On the back on your explanation write 3 things that you either learning or will work on for the next explanation. HOLD ON TO THIS TO STUDY! Break until ________