L01S10_Stoichiometry+01-20-10

L01S10_Stoichiometry+01-20-10 - Chem 1A, L1:...

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Unformatted text preview: Chem 1A, L1: "Atoms, Molecules, Stoichiometry" Heino Nitsche https://bspace.berkeley.edu/portal Lab Instructor/Lecturer : Dr.Chunmei Li, Latimer Hall Enrollment: Enrollment: Dr. Robert Lamoreaux, 211 Latimer Demo Supervisor: Karen Karen Chan Head TA: Greg Dallinger, chem1a.sp10@gmail.com Dallinger, © 2010 Pines,Kubinec,Nitsche, UCB Welcome to Chem1A Office Hours Wednesday 4-5 and Friday 3-4 p.m. 43Location: 446 Latimer Hall Prof. Nitsche Weekly Review Sessions Thursday 5-7 p.m. 51 Pimentel Hall Greg Dallinger Dallinger Open Office Daily, next week, see posted schedule B12 Latimer Hall © 2010 Pines,Kubinec,Nitsche, UCB ChemQuiz© 1.0 How many years of chemistry did you have in high school? A) 0 B) 0.5 C) 1 D) 2 or more © 2010 Pines,Kubinec,Nitsche, UCB © 2010 A.Pines, M.Kubinec, H. Nitsche UCB 1 Chem 1A, L1: "Atoms, Molecules, Stoichiometry" ChemQuiz© 1.1 Do you plan to go to Medical School A) Absolutely B) Undecided C) No © 2010 Pines,Kubinec,Nitsche, UCB Lab 1: Airbags •Goal: Design a reaction using acetic acid and sodium bicarbonate that will evolve the largest amount of CO2 gas to inflate a plastic bag •Tools such as stoichiometry, molar mass stoichiometry, and balancing chemical equations are necessary to help you predict what will optimize your airbag © 2010 Pines,Kubinec,Nitsche, UCB Summary 2H2 Energy Reactants + Chemical Reactions O2 2H2O High Road (barrier) Products Reaction Coordinate © 2001 UC Regents L1-4 Relative Atomic and Molecular Mass H 1.01 12C 2H2 + O2 2H2O Al 26.98 P 30.97 Fe 55.85 Pb 207.2 H2 2.02 O2 32.00 H2O 18.02 CO2 44.01 12.00 C 12.01 O 16.00 2 molecules + 1 molecule 2 moles + 1 mole 2 grams + 16 grams 2 molecules 2 moles 18 grams © 2010 Pines,Kubinec,Nitsche, UCB © 2010 A.Pines, M.Kubinec, H. Nitsche UCB 2 Chem 1A, L1: "Atoms, Molecules, Stoichiometry" Chemical Reactions 2H2 Energy Reactants Products Reaction Coordinate © 2010 Pines,Kubinec,Nitsche, UCB + O2 2H2O Transition State High Road (barrier) Scanning Probe Microscopy Can Image Single Atoms Image of a ring of cobalt atoms placed on a copper surface An Scanning Tunneling Microscopy (STM) image of nickel atoms placed on a copper surface. © 2010 Pines,Kubinec,Nitsche, UCB Stoichiometry Relationships between quantities of matter that participate in chemical reactions. Macroscopic Bulk matter NA Microscopic Atoms, Molecules Avogadro’s Number: NA = 6.022 x 1023 6.022 12 12C = one Mole NA atoms in 12.00 g Molar Mass (g/mol) © 2010 Pines,Kubinec,Nitsche, UCB © 2010 A.Pines, M.Kubinec, H. Nitsche UCB 3 Chem 1A, L1: "Atoms, Molecules, Stoichiometry" is assigned exactly 12 atomic mass units (amu or u) • Masses of all other atoms are given relative to this standard • Atomic masses are averages of isotopic masses • Relation between amu and grams 1 amu = 1.661 x 10-24 g = 1.661 x 10-27kg 6.022 x 1023 amu = 1 g (6.022 x 1023 atoms) (12amu/atom) = 12 g © 2010 Pines,Kubinec,Nitsche, UCB • 12C Atomic Mass and Mass Units Relative Relative Atomic and Molecular Mass H 1.01 12 12 C Al 26.98 P 30.97 Fe 55.85 Pb 207.2 H2 2.02 O2 32.00 H2O 18.02 CO2 44.01 12.00 C 12.01 O 16.00 © 2010 Pines,Kubinec,Nitsche, UCB ChemQuiz ChemQuiz© 1.2 What mass (g) of methane is required to react completely with 4 g of oxygen as shown? C H4 + 2 O 2 CO 2 + 2 H 2 O Relative masses: O2 = 2 x CH4 A) ~1 © 2010 Pines,Kubinec,Nitsche, UCB B) ~2 C) ~4 g © 2010 A.Pines, M.Kubinec, H. Nitsche UCB 4 Chem 1A, L1: "Atoms, Molecules, Stoichiometry" Molecules, Moles, Mass 2H 2 + O2 2H2O 2 molecules + 1 molecule 2 moles + 1 mole 2 grams + 16 grams 16 © 2010 Pines,Kubinec,Nitsche, UCB 2 molecules 2 moles 18 grams Stoichiometry Relationships between quantities of matter that participate in chemical reactions. 2H2 Energy + O2 2H2O Transition State High Road (barrier) Low Road (catalyst) Reactants Products Reaction Coordinate © 2010 Pines,Kubinec,Nitsche, UCB Lecture Complete © 2010 Pines,Kubinec,Nitsche, UCB © 2010 A.Pines, M.Kubinec, H. Nitsche UCB 5 ...
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