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Chemistry Monday, March 13, 2017

Do-Now: On Worksheet 1. When you’re finished with the do-now

questions, take out your ToC and planner

Announcements • ScienceNight3/17

– Volunteerforwhole6me,orpart6me(3-4:30or4:30-6:30)

– Receivevolunteerhoursand/orstamps

• Usedojopoints!• CSAthisThurs/Fri

Planner: •  Bring Calculators

Table of Contents #2: 8.  Boyle’s Law Graph WS

Graphing Reminders

Chemistry Tuesday, March 14 – Wednesday, March 15,

2017

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Earthquake Drill Reminders 1. Wait for drill to start 2.  Drop, cover, and hold

until instructed to evacuate

3. When evacuating: Walk together down the stairs to the football field

4. We will line up together and take attendance when we’re at the field.

Do-Now: “14.2 Cornell Notes” 1. Write down today’s FLT 2.  State one part of the Kinetic Molecular

Theory applied to gases 3. What are the three factors that affect gas

pressure? 4.  If you increase the temperature of a gas,

what happens to pressure? 5.  If you increase the volume of a gas, what

happens to pressure? Take out your planner, ToC, and a calculator

Announcements • ScienceNight3/17• Usedojopoints!• CSAthisThurs/Fri

Planner: •  Finish WS •  Lab Thurs/Fri: Hair Ties/Close-Toed shoes • Complete all retakes this week

Table of Contents #2: 9.  14.2 Cornell Notes 10.  14.2 WS

FLT •  I will be able to describe and quantify the

relationships among temperature, pressure, and volume of a gas by completing 14.2 Cornell Notes

Standard HS-PS1-5:Applyscien6ficprinciplesandevidencetoprovideanexplana6onabouttheeffectsofchangingthetemperatureorconcentra6onofthereac6ngpar6clesontherateatwhichareac6onoccurs.

14.2: The Gas Laws

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Recall

Factors Affecting Gas Pressure FourVariablesforDescribingGases:

1. Pressure(P)inkPa2. Volume(V)inL3. Temperature(T)inK4. NumberofMoles(n)inmol

•  V,T,andnaffectthePressureofagas

Factors Affecting Gas Pressure DirectorInverseRela6onship?

•  PressureandAmount(Pandn)

Factors Affecting Gas Pressure DirectorInverseRela6onship?

•  PressureandVolume(PandV)

Factors Affecting Gas Pressure DirectorInverseRela6onship?

•  PressureandTemperature(PandT)

Gas Laws

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The Gas Laws • The gas laws tell us how gases

behave • The amount of change can be

calculated with mathematical equations.

Boyle’s Law

Robert Boyle (1627-1691)

• Boyle became interested in medicine and the new science of Galileo and studied chemistry.

•  A founder and an influential fellow of the Royal Society of London

•  Wrote extensively on science, philosophy, and theology.

Boyle’s Law • When T is held constant, P is

inversely proportional to V

Boyle’s Law • Equation: • P / V = k • P1V1 = P2V2 •  (T must be

constant)

Boyle’s Law Ex 1/ •  A balloon contains 30.0 L of He gas at 103

kPa. What is the volume of He when the baloon rises to an altitude where the pressure is only 25.0 kPa? Assume that T remains constant.

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Ex 2/ •  Nitrous oxide (N2O) is used as an

anesthetic. The pressure on 2.50L of N2O changes from 105 kPa to 40.5 kPa. If the temperature does not change, what will the new volume be?

Charles’s Law

Jacques Charles (1746-1823) •  French Physicist •  Part of a scientific balloon

flight on Dec. 1, 1783 – was one of three passengers in the second balloon ascension that carried humans

•  This is how his interest in gases started

•  It was a hydrogen filled balloon – good thing they were careful!

Charles’s Law • When P is held constant, T is

directly proportional to V

Charles Law • Gas law problems involving temperature will always require that the temperature be in Kelvin.

• Reason? There will never be a zero volume, since we have never reached absolute zero.

Kelvin = °C + 273 °C = Kelvin - 273 and

Charles’s Law Ex 1/ •  A balloon inflated in a room at 24°C has a

volume of 4.00 L. The balloon is then heated to a temperature of 58°C. What is the new volume if the pressure remains constant?

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Charles’s Law Ex 2/ •  If a sample of gas occupies 6.80 L at

325°C, what will its volume be at 25°C if the pressure does not change?

Gay-Lussac’s Law

Joseph Louis Gay-Lussac (1778 – 1850)

•  French chemist and physicist

•  Known for his studies on the physical properties of gases.

•  In 1804 he made balloon ascensions to study magnetic forces and to observe the composition and temperature of the air at different altitudes.

Gay-Lussac’s Law • When V is held constant, P is

directly proportional to T

Gay-Lussac’s Law Ex/ •  A sample of nitrogen gas has a pressure

of 6.58 kPa at 539 K. If the volume does not change, what will the pressure be at 211 K? Combined Gas Law

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Combined Gas Law • When only n is constant, we can

relate P, T, and V.

Combined Gas Law Ex/ 1 •  The volume of a gas-filled balloon is 30.0

L at 313 K and 153 kPa pressure. What would the volume be at standard temperature and pressure (STP)? (1atm = 101.325 kPa)

Combined Gas Law Ex/ 2 •  A gas at 155 kPa and 25°C has an initial

volume of 1.00 L. The pressure of the gas increases to 605 kPa as the temperature is raised to 125°C. What is the new volume?

CW • 14.2WS• ToCand/orstudyCh.14

Chemistry Thursday, March 16 – Friday, March 17, 2017

Do-Now: CSA Day 1. Write down today’s FLT: I will be able to

determine the amount of water contained in a popcorn kernel by completing CSA Q3

2. Molar mass allows me to convert from _______ to _______

3. We will be using bunsen burners today. Remind me: how do we use them safely?

4.  You should be working in groups of 3-4. Make sure you’re sitting next to your group members.

Take out your planner, ToC, and a calculator

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Announcements • ScienceNight3/17

– EarlyvolunteersmeetinmyroomaRer8thper.

• Usedojopoints!• CSAtoday

– Experimenttoday– Nextclass:oraldefense.3-5minutepresenta6onofpurpose,experimentprocedure,data,calcula6ons,andconclusion.

Planner: • Oral defense on Monday •  Study Ch. 14

Table of Contents #2: 9.  14.2 Cornell Notes 10.  14.2 WS 11. CSA Day Do-Now

CSA • Whatisinapopcornkernel?

CSA • Howmuchwaterisinpopcorn?

CSA • Howcanweusetoolsinthelaboratorytodeterminetheamountofwaterinakernel?

Part A: Pre-Lab • Answertheques6ons• Useyourperiodictable• Showallworkandunits• Outlineyourstepstodeterminehowmuchwaterisinakernel

• GetstampedoffbyMs.Fleming

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Part B: Experiment • Youwilluseonetypeofkernelàlabelitinyourdatatable

• Performtheexperimentusing5-8kernels(toseeachangeinmass)

• Youcannotburnkernelsalltheway.Waitforkerneltocoolbeforemassing.

•  Finddatafromothergroupsforothertypesofkernels

• GetstampedoffbyMs.Fleming

Part C: Post-Lab Questions • Completetheques6onswithyourgroup

• Whenfinished,workontheoraldefenseques6ons

• Youwillneedtobereadytopresent(individually)onMonday.

• Presenta6onsaregradedoneffortandtheabilitytodiscusspurpose,procedures+results.Dishonesty=0.