Exam 3 Study Guide - Fundamentals of Chemistry | CHEM 107, Exams of Chemistry

Download Exam 3 Study Guide - Fundamentals of Chemistry | CHEM 107 and more Exams Chemistry in PDF only on Docsity! C107, FOB Oct. 1, 2008 CHEMISTRY 107: FUNDAMENTALS OF CHEMISTRY REVIEW TOPICS FOR HOUR EXAM 3 (Oct. 21, 2008) n.b. 1) These topics are NOT exhaustive. Assigned and unassigned problems and lecture material are fair game, as is all material in assigned text chapters. 2) Be able to give an example of each type of object, phenomenon, classification, etc. mentioned below. 3) * Indicates likely numerical calculation Chapter 8: Given some particular chemical reaction, how many moles of one reactant are needed to react with a given number of moles of another reactant? To form a specified number of moles of some product? Given some particular chemical reaction, what mass of one reactant is needed to react with a given mass of another reactant? To form a specified mass of some product? tna reaction where amounts of reactants and actual resulting products are given in moles, what are the limiting reactant, the theoretical yield, the actual yield and the percent yield? In a reaction where amounts of reactants and actual resulting products are given as masses, what are the limiting reactant, the theoretical yield, the actual yield and the percent yield? Limiting Reactant ~ The reactant that is completely consumed in a chemical reaction heoretical Yield — The amount of product that can be made in a chemical reaction based on the amount of limiting reactant. Actual Yield—The amount of product actually produced by a chemical reaction Percent Yield - Actual Yield/Theoretical Yield x 100% What is the enthalpy change associated with a process? How are exothermic and endothermic processes defined in terms of their associated enthalpy changes? DeltaHRxn ~ depends on the directian in which thermal energy flows when the reaction occurs. If thermal energy flows out of the reaction (exothermic) and into the surroundings, the Hon is negative, If thermal energy flows into the reaction (endothermic) and out of the surroundings then Hrxn is positive. Given a reaction enthalpy H for some chemical reaction, what heat change will occur ifa given number of moles or grams of some compound react? Chapter 9: What is the speed of fight in vacuo and what is the relation between the speed of light, the wavelength of a particular color or light and the frequency of that color? right is a form of electromagnetic radiation, a type of energy that travels through space at a constant speed of 3.0x108 m/s (186,000 m/s). Wavelength - the distance between adjacent wave crests, Frequency - The number of cycles or crests that pass through a stationary point in one second. Wavelength are inversely related the shorter the wavelength the higher the frequency. Also the shorter the wavelength the greater the energy of each photon. What terms are applied to EM radiation in various wavelength and/or frequency ranges? €The electromagnetic spectrum includes all wavelengths of electromagnetic radiation. {t ranges from longest to shortest radio waves, microwaves, infrared radiation, ultraviolet radiation, x rays, gamma rays. : What colors do we use to describe light with various wavelengths between 400-700 nm? e.g. 632 nm=red. 3K ROY G BV - Red, Orange, Yellow, Green, Blue, Violet What is an atomic emission spectrum and how is it obtained? Emission Spectrum - A spectrum associated with the emission of electromagnetic radiation by elements Qrcompounds What did the discrete lines in atomic emission Spectra suggest to Bohr about the nature of the atom?  Be able to write correct Lewis structures for binary ionic compounds. How can single, double and triple covalent bonds arise from pair of atoms attempting to acquire an octet of electrons by sharing? Be able to correctly write Lewis structures for simple covalent compounds, including polyatomic ions, What are some exceptions to the octet rule? # Odd numbers of electrons, boron which tends to form compounds with only 6 electrons, SE6 and Pci5 have more than 8 electrons ar \. What is the meaning of resonance in chemicat bonding? Be able to write resonance structures for species where resonance occurs. Resonance Structures - Two or more Lewis structures that are necessary to describe the banding in a molecule orion. Explain the VSEPR theory of molecular shape and use the theory to predict the shape of specific molecules. Know the terms used to describe the various shapes of molecules, e.g. ” trigonal planar’. VSE PR feValence shell electron air repulsion theory can be used to predict the shapes of molecules. Linear, trigonal planar, tetrahedral, trigonal pyramidal, and bent) What is the electronegativity of an element, how does the quantity vary within the periodic table and how do the relative electronegativities of two atoms determine the type of bond they form? Electronegativity - The ability of an element to attract electrons within a covalent bond. From left to right is increasing in electronegativity. What are polar covalent bonds and when do such bonds form between two atoms? How can a molecule be non-polar when its individual bonds are polar? Polar Covalent Bonds - A bi s of different electronegativities. Polar covalent bonds have a dipole moment. _— Alan - Fromermie extra cerensed tAikun - Endo Merwic Ett, a. vSorbe ave length Nee He Wiquer be freqnency 3 Shovxer Ye Wad lems RLMAL UXG Photon- pacarete of Weght - Arcee ety TeAate? 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