CHEM 1A03 Test #1 Review - CHEM 1A03 Test#1 Review Chapter...

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Introduction to General, Organic and Biochemistry
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Chapter 20 / Exercise 20-24
Introduction to General, Organic and Biochemistry
Brown
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CHEM 1A03 Test #1 Review Chapter 1-4, 6 – Fundamental Skills Review Oxidation state or oxidation number: Actual charge of a monatomic ion: Cl - (-1), Mg 2+ (+2) Group 1, 2 metals = O.N +1, +2 O is usually -2, F is -1, H is usually +1 except in metal hydrides (eg. NaH) -ous = lower oxidation state; -ic = higher oxidation state Nomenclature Simple ions – Fe(II) Ionic compounds – NaCl Binary molecular compounds – N 2 O 3 Polyatomic ions – CrO 4 2- Representation of Structure Ionic compounds: cations (M + ) + anions (X - ) = formula units (MX) Molecules: o Empirical: CH 2 O (simplest) o Molecular: C 2 H 4 O 2 (actual) o Structural: condensed structural, line-angle stick formula, “ball and stick” molecular model, space filling Isotopes Z = atomic # (# p); A = mass # (#n + p) # electrons = # protons = neutral atom # electrons # protons = charged ion Temperature Scales 0 K = absolute zero 0⁰C = 273K Extensive/Intensive Quantities Extensive: depend on amount of substance involved (eg. m, V, heat (q)) o Box of 20 donuts have greater mass than a box of 10 Intensive: independent of the amount of stuff (eg. T, d, heat capacity, P) o Density of water will always stay the same no matter how much there is
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The document you are viewing contains questions related to this textbook.
Introduction to General, Organic and Biochemistry
The document you are viewing contains questions related to this textbook.
Chapter 20 / Exercise 20-24
Introduction to General, Organic and Biochemistry
Brown
Expert Verified
Sig Figs Multiplication/ Division: First perform all the operations, even if changing from one formula to another. Round off the result so that it has the same number of sig figs as the least of all those used in your calculation o Example: ( 2.5 m) x (2.01 m) x (2.755 m) = 13.843875 m o Answer = 14 m (2 sig figs) Addition/Subtraction: First perform all the operations. Round off your result so that you include only 1 uncertain digit. o Example: 15 3 . ml + 1. 8 ml + 9.1 6 ml = 16 3.96 ml o Answer = 16 4 ml (3 sig figs; only 1 uncertain digit) o Notice that the answer is rounded to the same precision as the least precise measurement, which was 153. Ml Some examples: 10.02 = 4, 1.00 = 3, 0.054 = 2, 3400 = 2, 3400. = 4, pH = 10.02 = 2 Solution, % mass, %volume % by mass = x g solute/ 100 g solute % by volume = x mL solute / 100 mL solution Dilutions: when two solutions are added together, volume increases therefore concentration decreases Stoichiometry and Yield If 1.8 mol NO and 1 mol O 2 reacts, what is the limiting reagent? o 2NO + O 2 NO 2 o NO is because it needs more moles to react If we actually get 1.6 mol NO 2 what is the percent yield? o Theoretical yield is 1.8 mol b/c NO is limiting reagent and there is a 1:1 ratio of NO:NO 2 o So… 1.6/1.8 x 100% = 89% Gas Laws PV =nRT Comes from: Boyle, Charles, and Avogadro Partial Pressure The partial pressure of a gas “A” (P A ) describes its contribution to the total pressure (P TOTAL ). Its derived from its fractional contribution to the total pressure Chapter 8 – Electrons in Atoms
Electromagnetic Spectrum Atomic Spectra Earth’s Protective Shield: Ozone Lower O 3 levels increase the transmittance of UVB radiation to earth (light reacts at the atomic level) UVB rad can ionize biological molecules (DNA, protein) Chronic exposure to UVB rays increase chance of skin cancer, cataracts, and mutations Body’s response: produce melanin (dark pigment) to filter UVB radiation Use of sunscreen containing UV absorbing chemicals to decrease exposure (broad

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