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Key Concepts PowerPoint

Chapter 3
Formulas, Equations, and Moles

  
03-00-02UN
Title
 Balancing chemical equations
Caption
 After writing the correct chemical formula for each reactant and product, balancing of the equation is then accomplished by placing coefficients in front of the appropriate chemical species. The coefficient 'multiplies' the number of each atom for a particular formula unit in order to balance the equation.
Notes
 When a coefficient is not specifed for a particular species in an equation, the coefficient is assumed to be 1.
Keywords
 reaction, equation, balancing, coefficients
03-00-03UN1
Title
 Balancing equations
Caption
 When balancing chemical equations, coefficients are added in front of a particular species indicating multiple numbers of a formula unit. Do not change subscripts found within a formula unit since this actually changes the identity of the intended reactant or product.
Notes
 Proper placement of coefficients
Keywords
 coefficients, equation, balancing
03-00-03UN2
Title
 Comparison of water and hydrogen peroxide
Caption
 Although these two molecules contain only hydrogen and oxygen, they are not the same compound.
Notes
 Structures of water and hydrogen peroxide
Keywords
 water, hydrogen peroxide
03-00-08UN
Title
 Worked Key Concept Example 3.3
Caption
 Write a balanced equation for the reaction between A (red spheres) and B (blue spheres) represented by the diagrams.
Notes
 Worked Key Concept Example 3.3
Keywords
 key concept, reaction, balancing
03-00-09UN
Title
 Key Concept Problem 3.3
Caption
 Write a balanced chemical equation for the reaction between A (red spheres) and B (green spheres) as represented in the diagrams.
Notes
 Key Concept Problem 3.3
Keywords
 key concept, reaction, balancing
03-00-10UN
Title
 Formation of water
Caption
 The space-filling models of hydrogen and oxygen are shown to react and produce two molecules of water. The reaction equation is balanced.
Notes
 Formation of water
Keywords
 water, equation
03-00-11UN
Title
 Formation of ethyl chloride
Caption
 The molecules of ethylene and hydrogen chloride react and combine to form a new compound, ethyl chloride, which is used as a topical anesthetic.
Notes
 Formation of ethyl chloride, C2H5Cl
Keywords
 ethyl chloride, reaction
03-01
Title
 Relationship between mass and moles
Caption
 Figure 3.1 (a) Because one gumdrop weighs more than one jellybean, you can’t get equal numbers merely by taking equal weights. The same is true for different atoms or molecules. (b) Equal numbers of HCl and ethylene molecules always have a mass ratio equal to the ratio of their molecular masses, 36.5 to 28.0.
Notes
 Relationship between mass and moles
Keywords
 mass, mole
03-01-03UN
Title
 Formation of ammonia
Caption
 Instead of representing the number of individual atoms or molecules of a reactant or product, the coefficients in a balanced chemical equation also represent the number of moles of a reactant or product.
Notes
 Balanced equation for the industrial synthesis of ammonia—arrows pointing to moles of hydrogen, nitrogen, and ammonia
Keywords
 mole, ammonia, equation
03-01-04UN
Title
 Key Concept Problem 3.6
Caption
 Using the structural model shown, what is the chemical formula and molecular mass of methionine (red = O, gray = C, blue = N, yellow = S, ivory = H)?
Notes
 Key Concept Problem 3.6
Keywords
 key concept, formula, mass
03-02
Title
 Conversion between moles and mass
Caption
 Figure 3.2 A summary of conversions between moles and grams for a chemical reaction. The numbers of moles tell how many molecules of each reactant are needed, as given by the balanced equation; the numbers of grams tell how much mass of each reactant is needed.
Notes
 Conversion between moles and mass
Keywords
 mole, mass, conversion
03-02-02UN
Title
 Stiochiometry calculation
Caption
 Solving stoichiometry problems first involves having a balanced chemical equation. Take the known mass of a chemical species and convert it to moles using molecular mass as a conversion factor. Use the ratio of the appropriate equation coefficients to convert moles of one species to moles of another species. Finally, use the molar mass of the latter species to convert moles into grams.
Notes
 Worked Example 3.7
Keywords
 stoichiometry, calculation, conversion
03-02-03UN
Title
 Structure of aspirin
Caption
 Aspirin has the molecular formula C9H8O4.
Notes
 Structure can be used in conjunction with Problems 3.7 and 3.8
Keywords
 aspirin
03-02-04UN
Title
 Structure of methyl tert-butyl ether (MTBE)
Caption
 Ball-and-stick model of MTBE, C5H12O.
Notes
 Can be used in conjunction with Worked Example 3.8
Keywords
 MTBE, ether
03-02-05UN
Title
 Structure of diethyl ether
Caption
 Ball-and-stick model of diethyl ether.
Notes
 Can be used in conjunction with Worked Example 3.9
Keywords
 diethyl ether, ether
03-02-07UN
Title
 Formation of ethylene glycol
Caption
 Although the reaction equation shows that only one mole of ethylene oxide reacts with one mole of water to produce ethylene glycol, it is often the case in the laboratory that reactants are not mixed in the same ratios as the equation dictates.
Notes
 This example is meant to introduce the concept of 'limiting reactant' or 'limiting reagent'
Keywords
 limiting reactant, ethylene glycol
03-02-08UN
Title
 Effect of limiting reactant
Caption
 If water is in excess with respect to the balanced chemical equation, then the moles of ethylene glycol formed is dependent on the moles of ethylene oxide used. Therefore, some water will be left unreacted when the reaction is complete.
Notes
 Effect of limiting reactant
Keywords
 limiting reactant, ethylene glycol
03-02-09UN
Title
 Structure of cisplatin
Caption
 Ball-and-stick model of cisplatin.
Notes
 Can be used in conjunction with Worked Example 3.10
Keywords
 cisplatin
03-02-10UN
Title
 Balanced equation and limiting reactant
Caption
 Key Concept Problem 3.13 Write a balanced equation for the reaction and identify the limiting reactant.
Notes
 Key Concept Problem 3.13
Keywords
 key concept, balanced equation, limiting reactant
03-05
Title
 Molarity as a conversion factor
Caption
 Figure 3.5 A flow diagram summarizing the use of molarity as a conversion factor between moles and volume in stoichiometry calculations.
Notes
 Molarity as conversion factor
Keywords
 molarity, conversion, mole, volume
03-06
Title
 Acid-base titration
Caption
 Figure 3.6 A flow diagram for an acid-base titration, summarizing the calculations needed to determine the concentration of an HCl solution by titration with an NaOH standard solution.
Notes
 A flow diagram for an acid-base titration
Keywords
 titration, stoichiometry
03-08
Title
 Chemical formula from percent composition
Caption
 Figure 3.8 A flow diagram for calculating the formula of a compound from its percent composition.
Notes
 When only percent compositions of each element are given, assume you have 100.0 g of the compound and proceed with the calculations.
Keywords
 percent composition, formula, empirical
03-08-01UN
Title
 Structure of ascorbic acid (Vitamin C)
Caption
 Ball-and-stick model of ascorbic acid.
Notes
 Can be used in conjunction with Worked Example 3.15
Keywords
 ascorbic acid, vitamin C
03-08-03UN
Title
 Structure of glucose (blood sugar)
Caption
 Ball-and-stick model of glucose, C6H12O6.
Notes
 Can be used in conjunction with Worked Example 3.16
Keywords
 glucose, blood sugar
03-09
Title
 Empirical formula from combustion analysis
Caption
 Figure 3.9 A flow diagram for determining an empirical formula from combustion analysis of a compound containing C and H.
Notes
 Although the products carbon dioxide and water determine the number of moles of carbon and hydrogen in the sample, the number of moles of oxygen may need to be determined separately in order to account for the entire mass of the combusted sample.
Keywords
 combustion, empirical formula
03-09-01UN
Title
 Structure of naphthalene
Caption
 Ball-and-stick model of naphthalene, C10H8.
Notes
 Can be described as the primary ingredient to commercial moth balls (not to be confused with commercial moth crystals which are made from para-dichlorobenzene.
Keywords
 naphthalene
03-09-02UN
Title
 Structure of caproic acid
Caption
 Ball-and-stick model of caproic acid.
Notes
 Can be used in conjunction with Worked Example 3.18
Keywords
 caproic acid
03-10
Title
 Mass spectrometry
Caption
 Figure 3.10 (a) Schematic of a mass spectrometer. Sample molecules are ionized by collision with a high-energy electron beam, and the resulting ions are then passed between the poles of a magnet, where they are deflected according to their mass-to-charge ratio. The deflected ions pass through a slit into a detector assembly. (b) A mass spectrum of naphthalene, molec. mass = 128, showing peaks of different masses on the horizontal axis.
Notes
 Schematic of a mass spectrometer
Keywords
 mass spectrometer, mass spectrometry molecular mass
03-10-02.1
Title
 Key Concept Summary
Caption
 Formulas, equations, and moles key concept summary.
Notes
 Key Concept Summary for Chapter 3
Keywords
 key concepts, summary
03-10-03UN
Title
 Key Concept Problem 3.30
Caption
 Diagram for Problem 3.30.
Notes
 Key Concept Problem 3.30
Keywords
 key concept, dilution
03-10-04UN
Title
 Key Concept Problem 3.30
Caption
 Reaction of A (green spheres) with B (blue spheres) is shown schematically in the following diagram:
Notes
 Key Concept Problem 3.30
Keywords
 key concept, stoichiometry
03-10-05UN
Title
 Key Concept Problem 3.32
Caption
 Structure of cytosine, a constituent of DNA.
Notes
 Can be used in conjunction with Problem 3.32
Keywords
 cytosine
03-10-06UN
Title
 Key Concept Problem 3.33
Caption
 Reaction between NO and O2 to produce NO2.
Notes
 Key Concept Problem 3.33
Keywords
 key concept, reactant, product
03-10-07
Title
 Key Concept Problem 3.34
Caption
 Structure of fluoxetine (Prozac) (red = O, blue = N, yellow-green = F, ivory = H).
Notes
 Key Concept Problem 3.34
Keywords
 fluoxetine, prozac
03-10-08UN
Title
 Key Concept Problem 3.35
Caption
 Acid-base titration.
Notes
 Key Concept Problem 3.35
Keywords
 key concept, titration
03-10-09
Title
 Key Concept Problem 3.36
Caption
 Red and blue spheres to represent reaction of A2 and B2.
Notes
 Key Concept Problem 3.36
Keywords
 key concept, limiting reactant
03-10-10UN
Title
 Key Concept Problem 3.37
Caption
 A hydrocarbon of unknown formula CxHy was submitted to combustion analysis.
Notes
 Key Concept Problem 3.36
Keywords
 key concept, empirical formula, combustion analysis
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