Burns FUNDAMENTALS OF CHEMISTRY 4_e

Classifying Reactions

Classify reactions by what the atoms do

Type of Reaction General Equation

Synthesis A + B  AB

Decomposition AB  A + B

Displacement A + BC  AC + B

Double Displacement AB + CD  AD + CB









Burns Chapter 10 1

Types of Displacement Reactions

IV. Single Replacement Reaction

A + BC  AC + B

Zn(s) + Cu2+(aq)→Cu(s) + Zn2+(aq)‫‏‬









V. Double Displacement

AB + CD  AD + CB

Reactions in which 2 ionic compounds switch ions

K2CrO4(aq) + Ba(NO3)2(aq)→ BaCrO4(s) + 2KNO3(aq)



Burns Chapter 10 2

Bellringer

Balance and classify the following reactions:









Burns Chapter 10

Explain how to use the activity

series to predict whether or not

a single replacement reaction

will occur.









Burns Chapter 10

Activity Series

MORE REACTIVE

Demo:‫‏‬Will‫‏‬a‫‏‬reaction‫‏‬occur‫‏‬between‫.…‏‬



1) Fe + CuCl2 

Yes, Fe is above Cu, so..

Fe + CuCl2  Cu(s) + FeCl2

OBSERVATIONS:

Orangish precipitate forms

Blue solution disappears.





Which metal forms the solid?

The less reactive metal precipitates.

The more reactive metal goes into LESS REACTIVE

solution.

Burns Chapter 10 5

Activity Series

Will‫‏‬a‫‏‬reaction‫‏‬occur‫‏‬between‫.…‏‬ MORE REACTIVE



1) Mg + FeCl3 

Yes, Mg is above Fe, so..

3Mg + 2FeCl3  2Fe + 3MgCl2

2) NaCl + Cu

No, Cu is below Na

3) Cr + HBr 

Yes Cr is above H,

2Cr + 6HBr  2CrBr3 + 3H2



4) F2 +NaCl

LESS REACTIVE



Burns Chapter 10 6

Steps for Predicting Products of

Single Replacement Reactions.

1. Circle the more reactive metal.

2. Predict whether a reaction will occur.

3. Write products for neutral compounds

1. Metals replace metals

2. Nonmetals replace nonmetals

3. Write the cation first

4. (+) charges = (-) charges

5. REMEMBER DIATOMIC ELEMENTS

1. H2, O2, N2, F2, Cl2, Br2, I2

4. Balance the equation (only change coefficients).

5. Label phases (s), (aq), (g)

Pre-lab Single Replacement

Reactivity of Metals

HCl(aq) CuCl2(aq) NaCl(aq) MgCl2(aq)



Cu Cu Cu Cu Cu

Al Al Al Al Al

Mg Mg Mg Mg Mg

Zn Zn Zn Zn Zn





Cu + HCl  ? Mg + HCl  ? Zn + HCl  ?

Cu + CuCl2  ? Mg + CuCl2  ? Zn + CuCl2 ?

Cu + NaCl  ? Mg + NaCl  ? Zn + NaCl  ?

Cu + MgCl2 ? Mg + MgCl2 ? Zn + MgCl2 ?

Check-in

Mg + CuCl2 ?







Al + CuCl2 ?







Mg + NaCl?

Which metal Precipitates out of

solution???

Zn(s)  CuCl 2 (aq)  ???

The more active person goes into the dance.

The more reactive metal goes into solution.



The less active person sits down

The less reactive metal precipitates out.



Zn(s)  CuCl 2 (aq)  Cu(s)  ZnCl 2 (aq)

Replacement of Copper by Zinc

Zn(s)  CuCl2 (aq)  Cu(s)  ZnCl2 (aq)









Burns Chapter 10 11

Activity Series of the Halogens

F Why is F more reactive?

Cl Because it has the highest electronegativity

Br

I

Predict whether or not the following reactions will occur:

Br2 + NaCl  NR

MgI2 + Cl2  MgCl2 + I2

NaF + Cl2  NR



Burns Chapter 10

SR Practice Wksheet

1. Ag + LiNO3 →

2. Ba + CaCl2 →

3. Li + CaI2 →

4. Fe + HCl‫→‏‬

5. H2 + NaBr‫→‏‬



6. K + Pb(NO3)2 →

7. Cu + FeCl3 →

8. F2 + NaBr‫→‏‬

9. Cl2 + FeBr3→

10. I2 + FeCl3 →

In the penny demo,

Where does the zinc go?



Bubbles out as a gas

Decomposes

Dissolves into solution

Can’t tell

Post Lab

Sodium chloride______Magnesium chloride______

Hydrogen is diatomic____________

Never occurs alone – occurs with Cl or with another H

Good Conclusions:

“In‫‏‬order‫‏‬for‫‏‬an‫‏‬element‫‏‬to‫‏‬replace‫‏‬another,‫‏‬the‫‏‬replacing‫‏‬element‫‏‬

must be more reactive than the element being replaced. If it is not,

then‫‏‬no‫‏‬reaction‫‏‬will‫‏‬occur.”

“If‫‏‬the‫‏‬more‫‏‬reactive‫‏‬element‫‏‬is‫‏‬the‫‏‬element,‫‏‬we‫‏‬know‫‏‬the‫‏‬reaction‫‏‬

will occur. For example Mg reacted with CuCl2 because Mg is

more‫‏‬reactive‫‏‬than‫‏‬Cu.”

Four reactions occurred. Mg replaced H and Cu. Zn replaced H

and Cu. The metals being replaced are less reactive. Cu did not

react with anything. Neither did MgCl2(aq)‫‏‬or‫‏‬NaCl(aq).”

Post Lab Summary

Metals replace metals

Metals react with nonmetals (write the metal first).

A rxn will only occur when a ___________________

_____________________________________________

The less reactive metal forms the _________________

The more reactive metal goes ____________________



Sketch Cu(s) + AgNO3(aq) 

Sketch Zn(s) + AlCl3(aq) 

Sketch Ca(s) + HCl (aq) 

Sketch CuCl2(aq) + Zn (s) 

Dissociation

Potassium iodide dissociates in water into potassium

cations and iodide anions

KI(aq)‫ ‏‬ K+(aq)‫ + ‏‬I-(aq)‫‏‬

K I K+ I-





Copper(II) sulfate dissociates in water into

copper(II) cations and sulfate anions

CuSO4(aq)  Cu+2(aq) + SO4-2(aq)‫‏‬



Cu SO4 Cu+2 SO4-2



Burns Chapter 10 19

Dissociation

Potassium sulfate dissociates in water into

potassium cations and sulfate anions

K2SO4(aq)  2 K+(aq) + SO4-2(aq)‫‏‬

K+1

K SO4 K SO4-2

K+1









Burns Chapter 10 20