4.3 _Single and Double Replacement Reactions_ by tangshuming

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									Catalyst – March      17th   2010

1.   List 2 characteristics of combustion
     reactions.
2.   What is the general equation for a
     synthesis reaction?
3.   What do you think the products of the
     following decomposition reaction are:
           CaO  ? + ?
Today’s Agenda

 Catalyst
 Homework Review

 Chemistry Prom 2009 Day 2!

 Practice and Work Time

 GEE PREP

 Exit Question
Today’s Objectives

 SWBAT predict the products of single-
  replacement and double-replacement
  reactions.
 SWBAT differentiate between single-

  replacement and double-replacement
  reactions.
  Single and Double
Replacement Reactions
Drama on the Dance Flo!

 Key Point #1: A SINGLE-REPLACEMENT
  REACTION is one in which a single
  element replaces a similar element in a
  compound
 A + BX  AX + B

   A couple is dancing, and someone else cuts in
Single-Replacement in Action

           Example: Zn + CuCl2

      Cu      +   Zn           Zn      + Cu
 Cl        Cl              Cl        Cl



            A + BX  AX + B
     Single-Replacement Practice
1.    Predict the products of the reaction between solid
      copper and silver (I) nitrate.
        Write the reactants first.
        Then, write the products.


Cu + AgNO3                          Ag + Cu(NO3)2
                                      Must Kriss Kross to
                                       get the correct
                                          formulas!
Reactivity in the mix!

 Will a single-replacement reaction
  ALWAYS take place?
 Will there ALWAYS be cut-in drama

  on the dance flo?
 No, you have to check the reactivity

  series of metals and halogens
Reactivity in the mix!
 A metal will NOT ALWAYS replace another
  metal in a compound
 Reactivity is a substance’s ability to react with
  another substance
 The most active metals are on the top of the list
  on page 288
 More active metals will replace less active metals

     Example:   Ag (s) + Cu(NO3)2 (aq)  NO RXN!
                                                  K
    Reactivity Series                             Na
                                    No, Ni is     Li
                                    below is
                                           Na     Ca

                                   Yes, Li
 Metals near the top are most reactive and will   Mg
displacing metals near the bottom. above Zn       Al
                                                  Zn
                            Yes, Al is
Q: Which of these will react?                     Fe
                            above Cu              Ni
    1.   Fe + CuSO4  Cu + Fe2(SO4)3              Sn
                                                  Pb
    2.   Ni + NaCl   NR (no reaction) is
                              Yes, Fe
                                                  H
    3.   Li + ZnCO3  Zn + Li2CO3 Cu
                               above              Cu
    4.   Al + CuCl2  Cu + AlCl3                  Hg
                                                  Ag
                                                  Au
    Reactivity of Halogens
                                                           F

   The same goes for halogens
                                     Yes, F is
   More active halogens will replace less active halogens
                                    above Br               Cl
   List also on page 288
   Q: Which of these will react?       No, I is
                                       below Cl
                                                          Br
    F2 (g) + 2 NaBr (aq)       2 NaF (aq) + Br2 (l)

    I2 (g) + 2 KCl (aq)      NR (no reaction)             I
                                            K
Example Problem 10-2                        Na
                                            Li
                                            Ca
Write down the following reactants.    F    Mg
   Then, predict the products of the        Al
   reactions.                               Zn
                                       Cl   Fe
1.   Fe (s) + CuSO4 (aq)                   Ni
2.   Br2 (l) + MgCl2 (aq)             Br
                                            Sn
                                            Pb
3.   Mg (s) + AlCl3 (aq)                   H
                                       I    Cu
                                            Hg
                                            Ag
                                            Au
Swing Fever!

Key Point #2: A DOUBLE-
  REPLACEMENT REACTION is one in
  which ions switch places. You must
  KRISS-KROSS to write ALL formulas!
 AX + BY  AY + BX
   Two couples are dancing and decide to switch
    partners!
Double-Replacement in Action

      Example: MgO + CaS

 Mg       Ca       Mg         Ca
      +                  +
  O       S          S         O



      AX + BY  AY + BX
     Double-Replacement Practice
1.    Predict the products of the reaction between silver
      (I) nitrate and lithium iodide.
        Write the reactants first.
        Then, write the products.


AgNO3 + LiI                         LiNO3 + AgI
                                     Must Kriss Kross to
                                      get the correct
                                         formulas!
Let’s think about the positive and the
negative…cations and anions

         AX + BY  AY + BX

A and B are cations (positively charged)
X and Y are anions (negatively charged)

You can see the anions have switched places and
  are now bonded to the other cations in the
                    reaction
             PRACTICE!




Worksheet!
     Exit Question
1.   What are the 4 types of chemical reactions
     we have learned about so far at Chemistry
     Prom?
2.   Will the following reaction occur? Why or
     why not?
        Ni + AuBr3  NiBr2 + Au

								
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