Single and Double Replacement Reactions

7 Key excerpts on "Single and Double Replacement Reactions"

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  eBook - PDF

  General Chemistry: Atoms First

  • Young, William Vining, Roberta Day, Beatrice Botch(Authors)
  • 2017(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  Charles D. Winters Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-300 Unit 9 Chemical Reactions and Solution Stoichiometry 231 9.1b Displacement Reactions Many common chemical reactions are classified as displacement reactions , reactions where the number of reactants is typically equal to the number of products. In displace-ment reactions, also called exchange reactions, one atom, ion, or molecular fragment dis-places another. Displacement reactions can be single or double reactions. Single Displacement Reactions In a single displacement reaction , one molecular fragment is exchanged for another. A B 1 X S X B 1 A For example, when solid magnesium is placed in a solution of copper(II) chloride, the mag-nesium displaces the copper. In this case, the more reactive metal, magnesium, replaces the less reactive metal, copper. CuCl 2 (aq) 1 Mg(s) S MgCl 2 (aq) 1 Cu(s) Figure 9.1.2 Zinc reacts with iodine to form zinc iodide. Interactive Figure 9.1.3 Explore combination and decomposition reactions. The decomposition of mercury(II) oxide. Charles D. Winters Charles D. Winters Copyright 2018 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. WCN 02-300 Unit 9 Chemical Reactions and Solution Stoichiometry 232 Another common single displacement reaction occurs when a metal reacts with water. In the reaction of sodium metal with water, the metal displaces a hydrogen atom in water, forming sodium hydroxide (Figure 9.1.4). 2 H 2 O( / ) 1 2 Na(s) S H 2 (g) 1 2 NaOH(aq) Double Displacement Reactions A double displacement reaction , also called a metathesis reaction, occurs when two atoms, ions, or molecular fragments exchange. A B 1 X Y S A Y 1 X B There are three common types of double displacement reactions, each of which will be dis-cussed in greater detail later in this unit.

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  eBook - PDF

  Introductory Chemistry

  An Active Learning Approach

  • Mark Cracolice, Edward Peters, Mark Cracolice(Authors)
  • 2020(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  This, in turn, requires two Ag on the right. When you learn this technique, you will find it quicker and easier than balancing each element in a polyatomic ion separately. But remember the condition: All of the ions must be unchanged. This technique will not work, for instance, if there is an NO 3 2 compound on one side and an NO 3 2 plus an NO or some other nitrogen species on the other side. a summary of… Single-Replacement Reactions Reactants: Element (A) plus a solution of either an acid or an ionic compound (BX) or water Reaction type: Single-Replacement Equation type: A 1 1 1 AX BX 1 B Products: An ionic compound (usually in solution) (AX) plus an element (B) Learn It Now! Compare a summary of… Combination Reactions with a summary of… Decomposition Reactions with a summary of… Single- Replacement Reactions. 8.10 Double-Replacement Reactions Goal 8 Given the reactants in a double-replacement precipitation or neutralization reaction, write the equation. When solutions of two compounds are mixed, a positive ion from one compound may combine with the negative ion from the other compound to form a solid compound that settles to the bottom. The solid is a precipitate; the reaction is a precipitation reaction. In the equation for a precipitation reaction, ions of the two reactants appear to change partners. The equation, and sometimes the reaction itself, is a double-replacement equation or a double-replacement reaction. The general equation, with bridges to show the rearrangement of ions, is as follows: BY 1 1 1 AX BX 1 AY A typical precipitation reaction occurs between solutions of calcium chloride and sodium fluoride: CaCl 2 saqd 1 2 NaFsaqd S CaF 2 ssd 1 2 NaClsaqd. Copyright 2021 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).

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  eBook - PDF

  Basics for Chemistry

  • David A. Ucko(Author)
  • 2013(Publication Date)
  • Academic Press

    (Publisher)

  Still another example is the reaction of sodium hydroxide with sulfuric acid to form sodium sulfate and water. 2NaOH + H 2 S 0 4 N a 2 S 0 4 + 2 H 2 0 sodium sulfuric sodium water hydroxide acid sulfate The exchange that takes place here becomes clear if we think of the formula of water as H O H . Since water is not an ionic compound, its formation as a product effectively removes hydrogen ions and hy-droxide ions from the reaction. (This kind of reaction, between a base and an acid, is called neutralization and is discussed in Chapter Four-teen.) In each of these three examples of double replacement reactions, a set of ions was eliminated from the reaction, either as a precipitate, a gas, or a covalent compound. Table 9-2 summarizes the four major reaction types just discussed. The letters A, B, C, and D are general symbols for the elements in-volved. Another major category of reaction, discussed in detail in Chapter Fifteen, involves the transfer of electrons. These reactions are called 267 TABLE 9.2 Summary of reaction types Type Reaction combination (synthesis) decomposition replacement (substitution) a double replacement (metathesis) A + B -> AB AB AB + CD -> AD + CB AB + C —• AC + B A + B 9.7 WRITING CHEMICAL EQUATIONS Example Another possible reaction is AB + D -* DB + A oxidation-reduction, or redox reactions because they involve the si-multaneous processes of oxidation and reduction. One reactant loses electrons, becoming oxidized. Another reactant gains these electrons, becoming reduced. As explained in Sections 6.7 and 6.8, the formation of an ionic compound is an example of an oxidation-reduction reaction. We can separate an oxidation-reduction reaction into two half-reac-tions that clearly show the loss and gain of electrons: 2Na -> 2 N a + + 2 e ~ oxidation 2Na + C l 2 -* 2 N a C l The cation is formed by oxidation and the anion is formed by reduction.

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  eBook - PDF

  Basic Concepts of Chemistry

  • Leo J. Malone, Theodore O. Dolter(Authors)
  • 2012(Publication Date)
  • Wiley

    (Publisher)

  ANALYSIS To say that a metal is reactive means that it has a tendency to exist as an ion, not a free metal. To say that a metal is stable means that it is more often found in its metallic, or free, state. So compare Al and Pb. Which is more reactive? Which is more likely to be found in its free state? Which will replace which in a single-replacement reaction? The aluminum is more reactive. The lead is more stable. Therefore, solid aluminum will switch places with, or replace, aqueous lead ion in a single-replacement reaction. It’s worth noting that Table 6-2 also reflects the ease with which metals are recovered in mining. You can proceed up the list from the bottom and have a roughly accurate historical record of the order in which important metals were put into service by various cultures. E X A M P L E 6 - 5 Predicting Spontaneous Single-Replacement Reactions 194 CHAPTER 6 Chemical Reactions 6-5 Double-Replacement Reactions—Precipitation LOOKING AHEAD! In a single-replacement reaction, only cations are involved. In a double-replacement reaction, both cations and anions are involved. The driving force of these reactions is the formation of a product from the exchange of ions that is insoluble in water, is a molecular compound, or, in a few cases, is both. The first type of double- replacement reaction, formation of a solid, is discussed in this section. n 6-5.1 Soluble and Insoluble Ionic Compounds Marble statues have suffered the ravages of weather, for thousands of years in some cases. Marble, limestone, and chalk are essentially the same compound, calcium carbonate. Obviously, this ionic compound is insoluble in water. It formed when calcium ions (Ca 2+ ) and carbonate ions (CO 3 2- ) present in some ancient sea came together to form a solid deposit. Before we look at this type of reaction, we should bring some order and guidelines to the determination of which ionic compounds are soluble in water and which are not.

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  eBook - PDF

  An Introduction to Physical Science

  • James Shipman, Jerry Wilson, Charles Higgins, Bo Lou, James Shipman(Authors)
  • 2020(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  The answers to Confidence Exercises may be found at the back of the book. Trevor Clifford Photography / Science Source Figure 13.32 Metals and Acids Depending on the activity of a metal compared to hydro- gen, one can observe whether a single-replacement reaction will occur (left test tube) or will not occur (right test tube). Table 13.7 A Summary of Reaction Types Reaction Type Example Combination 2 Mg 1 O 2 4 2 MgO Decomposition 2 HgO 42 Hg 1 O 2 Hydrocarbon combustion (complete) C 2 H 4 1 3 O 2 4 2 CO 2 1 2 H 2 O Single-replacement (a) two metals Zn 1 CuSO 4 4 Cu 1 ZnSO 4 (b) metal and acid Fe 1 2 HCl 4H 2 1 FeCl 2 Double-replacement (a) precipitation BaCl 2 1 Na 2 SO 4 4 BaSO 4 (s) 1 2 NaCl (b) acid–base 2 HCl 1 Ca(OH) 2 4 2 H 2 O 1 CaCl 2 (c) acid–carbonate H 2 SO 4 1 Na 2 CO 3 4 H 2 O 1 CO 2 1 Na 2 SO 4 (The H 2 CO 3 that is initially formed decomposes.) Figure 13.33 Active Metals and Water Metals, such as calcium, that are above magnesium in the activity series react with water to form hydrogen gas and the metal hydroxide. Notice that no reaction is occurring between magne- sium and water (left beaker) but that hydrogen gas is being formed at a rapid rate as calcium reacts (right beaker). Ken O’Donoghue/Cengage Copyright 2021 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 392 Chapter 13 ● Chemical Reactions Did You Learn? ● ● Oxidation occurs when oxygen combines with a substance, or when atoms lose electrons. ● ● The activity of a metal depends on its ability to lose electrons to ions of another metal.

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  eBook - PDF

  Chemistry for Today

  General, Organic, and Biochemistry

  • Spencer Seager, Michael Slabaugh, Maren Hansen, , Spencer Seager, Spencer Seager, Michael Slabaugh, Maren Hansen(Authors)
  • 2021(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  5.5 Combination Reactions Learning Objective: Can you classify reactions into the categories of redox or nonredox, then into the categories of decomposition, combination, single replacement, or double replacement? ● Combination reactions are characterized by two or more reac- tants that form a single compound as a product. ● Combination reactions can be redox or nonredox. ● They can also be called addition or synthesis reactions. 5.6 Replacement Reactions Learning Objective: Can you classify reactions into the categories of redox or nonredox, then into the categories of decomposition, combination, single replacement, or double replacement? ● Single-replacement reactions, sometimes called substitution reactions, are always redox reactions. ● One element reacts with a compound and displaces another element from the compound. ● Double-replacement reactions, also called metathesis reac- tions, are always nonredox reactions. ● They can be recognized by their partner-swapping characteristics. 5.7 Ionic Equations Learning Objective: Can you write molecular equations in total ionic and net ionic forms? ● Many water-soluble compounds separate (dissociate) into ions when dissolved in water. ● Reactions of such materials can be represented by molecular equations: ? ? in which no ions are shown. ? ? total ionic equations in which all ions are shown. ? ? or net ionic equations in which only ions actually undergo- ing a change are shown. 5.8 Energy and Reactions Learning Objective: Can you classify reactions as exothermic or endothermic? ● Energy changes accompany all chemical reactions. ● The energy can appear in a variety of forms, but heat is a com- mon one. ● Exothermic reactions liberate heat. ● Endothermic reactions absorb heat.

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  eBook - ePub

  Barron's Science 360: A Complete Study Guide to Chemistry with Online Practice

  • Mark Kernion, Joseph A. Mascetta, Barron's Educational Series(Authors)
  • 2021(Publication Date)
  • Barrons Educational Services

    (Publisher)

  PART V

  CHEMICAL REACTIONS

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  8 CHEMICAL REACTIONS AND THERMOCHEMISTRY

  WHAT YOU WILL LEARN

  Upon completing this chapter, you will be able to:

  •Identify the driving force for these four major types of chemical reactions and write balanced equations for each: combination (or synthesis), decomposition (or analysis), single replacement, and double replacement

  •Explain hydrolysis using a balanced equation •Identify and explain graphically enthalpy changes in exothermic and endothermic reactions •Use Hess’s Law to show the additivity of heats of reactions •Calculate enthalpy from bond energies

  Types of Reactions

  The many kinds of reactions you may encounter can be placed in four basic categories: combination, decomposition, single replacement, and double replacement.

  The first type, combination, can also be called synthesis. This means the formation of a compound from the union of its elements. Some examples of this type are

  The second type of reaction, decomposition, can also be referred to as analysis. This means the breakdown of a compound to release its components as individual elements or other compounds. Some examples of this type are

  The third type of reaction is called single replacement or single displacement. This type can best be shown by examples in which one substance is displacing another. Some examples are

  The last type of reaction is called double replacement or double displacement because there is an actual exchange of “partners” to form new compounds. Some examples of this are

  Predicting Reactions

  One of the most important topics of chemistry deals with the reasons why reactions take place. Taking each of the above types of reactions, let us see how a prediction can be made concerning how the reaction gets the driving force to make it occur.

  COMBINATION (SYNTHESIS)

  The best source of information in predicting a chemical combination is the heat of formation table. A heat of formation table gives the number of calories evolved or absorbed when a mole (gram-formula mass) of the compound in question is formed by the direct union of its elements. In this book, a positive number indicates that heat is absorbed, and a negative number that heat is evolved. It makes some difference whether the compounds formed are in the solid, liquid, or gaseous state. Unless otherwise indicated (g = gas, ℓ = liquid), the compounds are in the solid state. The values given are in kilojoules; 4.18 joules is the amount of heat needed to raise the temperature of 1 g of water one degree on the Kelvin scale. The symbol ΔH

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