Catalyst – November 28-10, 2009 • Write the BALANCED equations for the following: • C5H12 combusts in air. • Sodium and nitrogen gas undergo a synthesis reaction. • Nitrogen trifluoride decomposes.
Today’s Agenda • Catalyst • Chemistry Prom 2009 Day 2! • Practice and Work Time • Exit Question
Today’s Objectives • SWBAT predict the products of single-replacement and double-replacement reactions. • SWBAT differentiate between all five types of chemical reactions.
Chemistry Prom 2009! 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 an element in a compound • A + BX AX + B • A couple is dancing, and someone else cuts in
+ + Cl Cl Cl Cl Zn Zn Cu Cu Single-Replacement in Action Example: Zn + CuCl2 A + BX AX + B
Single-Replacement Practice • Predict the products of the reaction between solid copper and silver (I) nitrate. Write the reactants first. Then, write the products. Now, BALANCE! 2 2 Cu + AgNO3 Ag + Cu(NO3)2 Must Kriss Kross to get the correct formulas!
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!
No, Ni is below Na Yes, Li is above Zn Yes, Al is above Cu Yes, Fe is above Cu Reactivity Series • Metals near the top are most reactive and will displacing metals near the bottom. Q: Which of these will react? 1. Fe + CuSO4 2. Ni + NaCl 3. Li + ZnCO3 4. Al + CuCl2 Cu + Fe2(SO4)3 NR (no reaction) Zn + Li2CO3 Cu + AlCl3
No, I is below Cl Yes, F is above Br Reactivity of Halogens • The same goes for halogens • More active halogens will replace less active halogens • List also on page 288 • Q: Which of these will react? F2 (g) + 2 NaBr (aq) I2 (g) + 2 KCl (aq) 2 NaF (aq) + Br2 (l) NR (no reaction)
Example Problem 10-2 Write down the following reactants. Then, predict the products of the reactions. • Fe (Ox: 2+)(s) + CuSO4 (aq) • Br2 (l) + MgCl2 (aq) • Mg (s) + AlCl3 (aq)
Swing Fever! Key Point #2: A double-replacement reaction is one in which ions switch places. • AX + BY AY + BX • Two couples are dancing and decide to switch partners!
Ca Ca + + Mg Mg S S O O Double-Replacement in Action Example: MgO + CaS AX + BY AY + BX
Double-Replacement Practice • Predict the products of the reaction between silver (I) nitrate and lithium iodide. Write the reactants first. Then, write the products. Now, BALANCE! LiNO3 + AgI AgNO3 + LiI Must Kriss Kross to get the correct formulas!
Let’s think about the positive and the negative…cations and anions AX + BYAY + 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
Three Examples of Double Replacement Reactions • There are three types of double-replacement reactions – they form three different products • WATER • PRECIPITATE • GAS
Example 1 Ca(OH)2 + 2 HCl CaCl2 + 2 H2O Ions: Ca+2, OH-1, H+1, Cl-1 WATER IS FORMED!
Example 2 2 NaOH + CuCl2 2 NaCl + Cu(OH)2 Ions: Na+1, OH-1, Cu+2, Cl-1 SOLID IS FORMED – PRECIPITATE
Example 3 KCN + HBr KBr + HCN Ions: K+1, CN-1, H+1, Br-1 GAS IS FORMED
Double-Replacement Practice • Predict the products of the following reactions: • Page 291, #s 24-26
Reaction Practice Questions • Complete questions 27-32 on page 291 • Then, start on worksheet – finish for homework
Exit Question • What are the 5 types of chemical reactions? • Using the following reaction, answer the following questions: 3 Ni + 2 AuBr3 3 NiBr2 + Au a) Is the equation balanced? b) Will this reaction actually occur? Why or why not?