Sheets Page 1 Lecture 1
Chem 110: Chemical Principles 1
Sections 14–26 Mon/Wed/Fri 11:15-12:05
108 Forum
Dr. Erin D. Sheets
326 Chem Res Bldg 863-0044
courses.chem.psu.edu/chem110/spring
courses.chem.psu.edu/chem110/faculty/sheets (lecture notes)
Office hours: Mondays 12:30–2 &
Tuesdays 10:30–12
Questions?? Chem110 in subject line of email ensures a quicker response
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Some questions about everyday observations that weʼll answer this
semester… Why does rain fall as drops instead of as cubes or cylinders? How can some animals walk on ceilings? Why does salt help to melt snow from roads? Why is the sky blue? Why can some insects walk on water? Why is ozone depletion bad?
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How do we know what we know?? You know that… table salt contains Na+ and Cl– ions earthʼs atmosphere is 20% O2 DNA is a double helix … but … How do you know these facts? • experimental evidence • indirect evidence • logic
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Chemical & physical changes
Chemical Physical 2 H2 + O2 → 2 H2O evaporation firewood burns H2O → steam metals corrode freezing cement sets dry ice → CO2 gas eggs fry Chemical changes ⇒ reactions!!!
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Chemistry: study of matter & its transformations (physical & chemical)
We focus on molecules!!! Key concepts: • energy • macroscale ⇔ nanoscale observations molecular interactions • molecular structure effects its function
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Why are we starting with Chapter 6? Key themes: structure effects function (properties)
how do we know about atoms, etc.? structure of atoms, Ch. 6 properties of atoms, Ch. 7 how atoms form molecules, Ch. 8 structure of molecules, Ch. 9 properties of molecules, Ch. 10, 11, 13
molecules react! Ch. 3, 4, 10 rules that govern reactions
thermodynamics—think energy, Ch. 5 equilibrium, Ch. 15
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How to succeed in Chem 110
• attend lectures & recitations • invest the time: ~10 hours/week outside of class—studying & homework • read text before & after lecture • bring lecture notes; incomplete notes available on website; notes are only a guide (courses.chem.psu.edu/chem110/faculty/sheets) • do problems in text; do supplemental problems—work together & work alone • homework problems give good idea of what is expected—do ʻem! & understand ʻem!; homework done before recitation • Please donʼt fall behind!! Seek out help when you need it—donʼt wait until the day before the exam!
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How to succeed in Chem 110, part 2 (1)
• Suggestions from past Chem 110 students: Getting a study group early helps a lot. Even if its just people who you are comfortable asking questions with in class, it makes a large difference. Also you were right about studying and starting early as opposed to cramming. I would suggest to other students to keep up with the material and read the sections in the text book ahead of time. I felt that it was very useful to know what you would be talking about ahead of time, so that I could concentrate on the areas I did not quite understand. Please attend all lectures. If you think you have a strong grasp on the subject and then not attend for two weeks before the final...it will show in that subject area. I found that doing practice problems along with the lecture definitely helped because I would sometimes find myself a little lost in the words and explanation of the topics but then the example problems would help to put it all in prospective. For future chem 110 students, I highly recommend reading the book. I read the book the night after every lecture, which reinforced what was taught, and helped me understand what the book was saying. Sometimes reading the book before lecture was a little confusing, as I didn't have a preview of what we were learning. I would also recommend doing all of the homework, even if you have enough homework points. The homework provided perfect examples of quiz and test questions.
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How to succeed in Chem 110, part 2 (2) i would say that the best thing to do to succeed in chem 110 is to read the text- it helps so much. if you don't you will probably feel very lost in the lectures and it will make the homework ten times more difficult. and don't leave the homework until the last minute. make sure you let yourself take your time with it and make sure you understand it because thatʼs what the quizzes and the exams will be like. I would suggest doing the homework shortly after the lecture. It made it easier on me when I did the homework in conjunction with the lecture rather than waiting until, say, the weekend to do it. I think practice is the best way you can succeed in Chem 110. You need to do the homework problems and apply the concepts you learn to keep them in fresh in your mind. By trying to solve so many different problems you will be able to apply everything you will learn to solve any problem that deals with those concepts. ATTEND LECTURE! You can't do it by yourself. Also, start studying early because there is too much material on the exams to cram in the night before. Also, don't only rely on the practice exams, as they change from year to year and stress different things each year. Work on practice exams, but also review the lecture notes and homeworks. The only suggestions I have for future students is to actually read the sections in the book assigned for each week and to put real effort into the homework problems. Just copying down the answers from the back of the book or the solution manual will not help them out on the exams.
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How to succeed in Chem 110, part 2 (3) In order to succeed in CHEM 110, all you have to do is read the book, do the problems, and go to lecture. And oh yeah, don't ever get satisfied with a grade! That, to me, is extremely key! I got very high grades on my last two exams in class, so I think I relaxed a little too much when it came down to the final exam. I still did well in the class (probably a "B+"), but I certainly could have done better (probably could have kept that "A"). Be happy when you get good grades, but don't ever get too comfortable! You're rarely ever completely locked into a grade! I know that most of you guys heard that Chem 110 sucks. I have to admit that was the first thing I heart about Chem 110. There is nothing difficult in this class, as long as you keep doing your homework and be present in all Dr. Sheetsʼs Lectures. After all they are so much fun. Do not just study the day before the exam, you will regret it. I had no previous chemistry background but I still managed to get an A in this class. Do you homework, quizes and BST, they worth a lot of "easy to get" points. Always try to understand the concepts of the lecture rather than memorizing things. At the end of the semester you will realize that you learned lots of things. Attending lecture and doing the assigned textbook reading are important. Doing one without the other doesn't work because there is extra information in the book that we don't cover in lecture, and there are things we learn in lecture that aren't in the book. Also, doing the example problems in class is important. Just watching when the instructor does them isn't usually sufficient (for me, at least). Working through them while the instructor works through them is the best way to understand them.
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Chemistry Undergraduate Office • 210 Whitmore: helps with registration, drop/add (ends Wednesday, Jan 23), incorrect exam grades, other red tape issues
Chemistry Resource Center (CRC) • 211 Whitmore FREE TUTORING!!! • grad student TAs & undergrad science majors; hours posted on web
Supplemental Instruction (SI)
• FREE help for Chem 110—starting in 1–2 weeks, announced in class & on web (more later); through University Learning Centers (not Chem Dept)
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Midterm Exams • Monday evenings @ 6:30 pm; more info later • Keep these dates/times open!
• Exam 1: February 9 6:30 pm • Exam 2: March 2 6:30 pm • Exam 3: April 6 6:30 pm
• Locations: TBA (posted on the web before every exam) • (almost) No Make-up exams given
Final Exam • during week of May 4–8 Do not make plans to leave town!
time & place TBA (usually announced in early March)
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Online pre-quiz: must finish by Wednesday, January 14
• NOT counting toward Chem 110 grade • guidance for correct course placement
Prerequisites
• see general course info on website
• Algebra • High school chemistry
Chapters 1, 2 Familiarity with Chapters 3, 4, 10
NOTE: Chem 110 assumes previous exposure to Chemistry—we move very quickly Chem 108 is 1-credit add-on to Chem 110 for students needing more help (add NOW during drop/add period) No previous chemistry? Chem 101 better option; Chem 110 not appropriate
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About Grades
Exam 1, 2, 3 34 points each Final exam 58 points Quizzes* 15 points (recitation) Homework 15 points (recitation)
Basic skills tests 10 points (online) Total 200 points
NOTE: Quizzes & homework can raise grade by 1 letter grade *Quizzes based on homework and assigned materials—more in recitation & in course packet
Grading
• grade distribution given in course packet • curve: NO!!!!
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Course goals • learn principles chemists use to understand & manipulate the material world • relate macroscopic properties of materials to microscopic structures • understand chem-speak (chemical literacy) • understand world around you • learn how to think & problem-solve
My goals for you • Chemistry is interesting & fun! • Understand chemistry, not memorize facts • Make connections, get overview, place in context
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Now, on to Chap 1 (todayʼs assignment) …
Read: BLB Chap 1 HW: BLB 1:17, 24a–d, 27, 48, 58; Sup 1:1–5
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Uncertainties Precision: how close values are with respect to each other Accuracy: how close values are with respect to true value
Significant figures See text for determining number of sig figs & how to carry uncertainty through calculations 854 ⇒ 8.54 × 10 0.00854 ⇒ 8.54 × 10 85400 ⇒ 8.54 × 10
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SI units • some important base units
mass: kg length: m time: s temperature: K (K = 273.15 + °C)
• some important prefixes: know these!
mega (M): 10
kilo (k): 10 centi (c): 10 milli (m): 10 micro (µ): 10 nano (n): 10
1 cm = 1 × 10–2 m or to put it another way, 1 × 102 cm = 1 m convince yourself that these are equivalent
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Example: A laser emits 488 nm light. What is this wavelength in meters (shown)? In centimeters (you do on your own)?
488nm( )1!10"9
m
1nm
#$%
&'(= 4.88 !10"7
m
alternatively, you could do this conversion as
488nm( )1m
1!109nm
#$%
&'(= 4.88 !10"7
m
Use whichever conversion that makes sense to you, and be consistent. Always use units!!! and always ask yourself whether the answer makes sense!
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Problem Solving: Itʼs all about making connections
• What are you given? • What else do you know? • Organize the information. • What connections can you make? Example: An unknown liquid has a density of 2.14 g/mL. How many mL would a 6.42 g sample of this liquid occupy if dispensed into a 5 mL UV/VIS spectrophotometer cuvette?
units are your friends: use them!!
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Before next class: Read: BLB Chap. 2.3–2.4; 5.1–5.3; 6.1 HW: BLB 2:4,23,25,31; 5:3,25,28
Sup 2:1–3; 6:1, 3,4,5—do NOT do Sup 6.2! Know: • the mole • atomic structure—protons, neutrons, electrons • atomic weights • kinetic & potential energy • conservation of energy • energy: system & surroundings • wavelength, frequency of light • E = hν Answers: p. 19: 4.88 × 10–7 m; 4.88 × 10–5 cm p. 20: 3.00 mL
