chapter 7 preparation

Chapter 7 Preparation

CHAPTER 7

Identifying Reaction Types (continued)

BLM 7.0.1

ASSESSMENT

9. Classify each of these reactions into one of the following reaction types: formation (F),single replacement (SR), simple decomposition (SD), double replacement (DR), combustion (C), or other (O).

F (a) Ti(s) + 2Cl2(g) → TiCl4(ℓ) SD (c) HCOOH(ℓ) → C(s) + H2(g) + O2(g) C (e) CH3COOH(ℓ) + 2O2(g) → 2CO2(g) + 2H2O(g)

F (g) 2C(s) + 4H2(g) + O2(g) → 2CH3OH(ℓ) SR (i) Br2(ℓ) + 2NaI(aq) → 2NaBr(aq) + I2(s) SD (k) 8H2SO4(ℓ) → 8H2(g) + S8(s) + 16O2(g)

SR (m) Sn(NO3)2 (aq) + Cd(s) → Sn(s) + Cd(NO3)2(aq) F (o) 2Ag(s) + O2(g) + H2(g) → 2AgOH(s) DR (q) H3PO4(aq) + 3NaOH(aq) → 3HOH(ℓ) + Na3PO4(aq)

DR (s) Ba(NO3)2(aq) + 2NaCl(aq) → BaCl2(s) + 2NaNO3(aq)

SR (u) I2(s) + Na2Se(aq) → 2NaI(aq) + Se(s)

F (w) 2Au(s) + 3Cl2(g) → 2AuCl3(s)

C (y) 2C2H2(g) + 5O2(g) → 4CO2(g) + 2H2O(g)

BLM 7.0.3

(a)____C6H10O5(s) + ____O2(g) → ____CO2(g) + ____H2O(g)

(c)____Sc2O3(s) + ____H2O(ℓ) → ____Sc(OH)3(s)

(e)____ CH3COOH(ℓ) + ____O2(g) → ____CO2(g) + ____H2O(g)

(g)____C3H8(g) + ____O2(g) → ____CO2(g) + ____H2O(g)

(i)____Ca(s) + ____C(s) + ____O2(g) → ____CaCO3(s)

(k)____S2Cl2(ℓ) + ____NH3(g) → ____S4N4(s) + ____S8(s) + ____NH4Cl(s)

(m)____Ag(s) + ____O2(g) + ____H2(g) → ____AgOH(s)

(o)____CrCl2(aq) + ____Mg(s) → ____MgCl2(aq) + _____Cr(s)

(q)____C8H18(ℓ) + ____O2(g) → ____CO2(g) + ____H2O(g)

(s)____Cu(s) + ____S8(s) + ____O2(g) → ____CuSO3(s)

(u)____CuSO4(s) → ____Cu(s) + ____S8(s) + ____O2(g)

(w)____Pb(s) + ____S8(s) + ____O2(g) → ____PbSO4(s)

(y)____BCl3(g) + ____H2O(ℓ) → ____H3BO3(s) + ____HCl(g)

1 6 6 5

1 3 2

1 2 2 2

1 5 3 4

2 2 3 2

6 16 1 1 12

2 1 1 2

1 1 1 1

2 25 16 18

8 1 12 8

8 8 1 16

8 1 16 8

1 3 1 3

1. Cyclopentane, C5H10(ℓ), reacts with oxygen to produce carbon dioxide and water vapour.

3.Phosphoric acid is neutralized by cesium hydroxide solution to produce cesium phosphate solution and liquid water.

5. Lead(II) acetate solution reacts with zinc metal to form zinc acetate solution and solid lead. 7. Calcium chlorate solution reacts with lithium sulfate and calcium sulfate

solid forms in a lithium chlorate solution.

9.Octane (C8H18(ℓ)) reacts with oxygen gas to produce carbon dioxide and liquid water in a bomb calorimeter.

BLM 7.04

Supply formulas and balance

2 C5H10(l) + 15 O2(g) 10 CO2(g) + 10 H2O(g)

1 H3PO4(aq) + 3 CsOH(aq) 3 HOH(l) + 1 Cs3PO4(aq)

Note: HOH(l) = H2O(l)

1 Pb(CH3COO)2(aq) + 1 Zn(s) 1 Zn(CH3COO)2(aq) + 1 Pb(s)

1 Ca(ClO3)2(aq) + 1 Li2SO4(aq) 1 CaSO4(aq) + 2 LiClO3(aq)

2 C8H18(l) + 25 O2(g) 16 CO2(g) + 18 H2O(l)

1. Ethylene (ethene), C2H2(g), forms from its elements.

3. Methanal, CH2O(ℓ), burns in oxygen gas.

5. Cyclohexane, C6H12(ℓ), undergoes combustion.

7. Benzene, C6H6(ℓ), combusts.

9. ________ + ________ → ____ PCl3(g)

11. ____C7H8(ℓ) + ________ →

BLM 7.0.5

Predictions: C, SD, F

2. Dihydrogen dioxide (hydrogen peroxide), H2O2(ℓ), decomposes into its elements.

Hint: determine reaction type 1st

(F)

(SD)

(C)

(C)

(C)

(F)

(C)

2 C(s) + 1 H2(g) 1 C2H2(g)

Review info about states on WS

1 H2O2(l) 1 H2(g) + 1 O2(g)

1 CH2O(l) + 1 O2(g) 1 CO2(g) + 1 H2O(g)

1 C6H12(l) + 9 O2(g) 6 CO2(g) + 6 H2O(g)

2 C6H6(l) + 15 O2(g) 12 CO2(g) + 6 H2O(g)

1 P4(s) 6 Cl2(g) 4

1 9 O2(g) 7 CO2(g) + 4 H2O(g)

BLM 7.0.6

Predictions:SR and DR

Review info about states on WS

Determine reaction type 1st

1. Liquid bromine reacts with a sodium iodide solution.

3. Calcium chloride solution reacts with ammonium sulphide solution.

5. Ethanoic acid reacts with a solution of potassium hydroxide.

7. Magnesium metal is put into a silver nitrate solution.

9. Silver nitrate solution is mixed with a lithium chloride solution.

11. Aluminium metal is added to a chromium(II) sulfate solution.

13. Aqueous chlorine is mixed with a solution of sodium selenide.

1 Br2(l) + 2 NaI(aq) 2 NaBr(aq) + 1 I2(s) or (aq)

1 CaCl2(aq) + 1 (NH4)2S (aq) 1 CaS(s) + 2 NH4Cl(aq)

(SR)

(DR)

(DR)

(SR)

(DR)

(SR)

(SR)

1 CH3COOH(aq) + 1 KOH(aq) 1 KCH3COO(aq) + 1 HOH(l)

1 Mg(s) + 2 AgNO3(aq) 1 Mg(NO3)2(aq) + 2 Ag(s)

1 AgNO3(aq) + 1 LiCl(aq) 1 AgCl(s) + 1 LiNO3(aq)

2 Al(s) + 3 CrSO4(aq) 1 Al2(SO4)3(aq) + 3 Cr(s)

2 Cl2(aq) + 2 Na2Se(aq) 4 NaCl(aq) + 1 Se2(s)

Chemistry 20

PowerPoint presentation byR. Schultz

[email protected]

Chapter 7

7.1 Reactions in Aqueous Solution

• Solution reaction equations are often written as net-ionic equations

• Consider reaction of lead (II) nitrate solution with potassium iodide solution:

1 Pb(NO3)2(aq) + 2 KI(aq) 1 PbI2(s) + 2 KNO3(aq)

equation called complete balanced equation or formula equation

Recall from previous unit that electrolytes dissociate (or ionize) in water


• leads to the ionic equation or total ionic equation

• dissociate all aqueous electrolytes and write all strong acids in ionic form

1 Pb2+(aq) + 2 NO3‾(aq) + 2 K+(aq) + 2 I‾(aq) 1 PbI2(s) + 2 K+(aq) + 2 NO3‾(aq)

• now look for spectators, chemical entities that don’t change

• cancel them out

• this leads to net ionic equation………

note that numbers from balanced equation are part of ionic equation


• net ionic equation:

1 Pb2+(aq) + 2 I‾(aq) 1 PbI2(s)+ 2 NO3‾(aq) + 2 K+

(aq)+ 2 K+(aq) + 2 NO3‾(aq)

1 Pb2+(aq) + 2 I‾(aq) 1 PbI2(s)

all precipitation reactions will have this basic type of net-ionic equation

try Practice Problem 2a, page 264: write ionic and net-ionic equations – note: original equation is unbalanced


• balanced:

• ionic:

• net ionic:

3 Ba2+(aq) + 6 ClO3‾(aq) + 6 Na+(aq) + 2 PO43‾(aq) 1 Ba3(PO4)2(s) + 6 Na+(aq) +

6 ClO3‾(aq)

3 Ba(ClO3)2(aq) + 2 Na3PO4(aq) 1 Ba3(PO4)2(s) + 6 NaClO3(aq)

3 Ba2+(aq) + 2 PO43‾(aq) 1

Ba3(PO4)2(s)

Practice Problem 2a, page 264


• Single replacement example:• complete balanced equation:

• ionic equation:

• net-ionic equation:

1 Zn(s) + 1 Cu(NO3)2(aq) 1 Zn(NO3)2(aq) + 1 Cu(s)

1 Zn(s) + 1 Cu2+(aq) + 2 NO3‾(aq) 1 Zn2+(aq) + 2 NO3‾(aq) + 1 Cu(s)

1 Zn(s) + 1 Cu2+(aq) 1 Zn2+(aq) + 1 Cu(s)

metal ions and metal elements are different!

Try Practice Problem 1c, page 264 (equation is balanced)


• ionic

• net-ionic

2 Al(s) + 3 Cu2+(aq) + 6 Cl‾(aq) 3 Cu(s) + 2 Al3+(aq) + 6 Cl‾(aq)

2 Al(s) + 3 Cu2+(aq) 3 Cu(s) + 2 Al3+(aq)

do worksheet BLM 7.1.2 questions 1-7

note that questions 3 and 7 are special – talk to me

all metal with ionic solution reactions will be similar


• Techniques of Qualitative Analysis– solution colour – see chart page 11 of Data

Booklet– flame colour – see chart page 6 of Data

Booklet: I don’t like chart titles – metals themselves don’t give colours – metal ions do

what is present, nothing about amount – concentration, mass, etc


Thought Lab 7.1 page 2671. Red flame and ppt with

OH‾(aq): 2. Red flame and ppt with

SO42‾(aq):

3. If all traces of Ca2+(aq) and Sr2+(aq) are removed, flame colour?

solubility chart page 6 Data Booklet

also need flame test colour chart, page 6 and ion colour chart, page 11

Ca2+(aq)

Ca2+(aq), Sr2+(aq)

yellow because NaOH(aq) and Na2SO4(aq) have been added

selective precipitation – solutions are added to the unknown solution to see whether or not precipitates form


• Thought Lab 7.1, question 4a) colourless solution; no ppts

• b)

• c)

• d)

blue solution; ppt with e.g. no ppt with e.g.

colourless solutionppt with e.g.

no ppt with e.g.

blue solutionppt with e.g.

no ppt with e.g.

Worksheet BLM 7.1.5

7.2 Stoichiometry and Quantitative Analysis

• Stoichiometry – a method of predicting quantities of reactants or products of a chemical reaction from quantities of another substance in the reaction

concept is based on mole ratios just as # sandwiches is based on #’s of each type of piece

figure 7.7, page 271

to double # sandwiches, double # of each sandwich piece


• Type 1: Gravimetric Stoichiometry

• Example: Practice Problem 12, page 278

based on mass

2 Mg(s) + 1 O2(g) 2 MgO(s)

n n1 n2

m 4.86 g xs ?

1

4.860.200

24.31gmol

gn mol

2

20.200 0.200

2n mol mol

? 0.200 40.31 8.06gmolm mol g

looking for

given


• Example: Practice Problem 15, page 278• Unbalanced equation given – balance it

• P4(s) + Cl2(g) PCl3(l)461

nm 323 g ?

n1 n2

1

3234.56

70.90gmol

gn mol

not part of molar mass

2

44.56 3.04

6n mol mol

? 3.04 137.32 417gmolm mol g

looking forgiven

Do Worksheet 30, Investigation 7.B.1


• Type 2: Solution Stoichiometry• Example: Practice Problem 16, page 282

based on solution concentrations and volumes, but same general strategy

1 MgCl2(aq) + 2 AgNO3(aq) 2 AgCl(s) + 1 Mg(NO3)2(aq) n1

0.30 mol/L60 mL

n2

0.50 mol/LV=?

1 0.30 0.060 0.018molLn c V L mol

0.0090

0.018 or 18 mL0.50mol

L

molV L

2

10.018 0.0090

2n mol mollooking for

given


• Note that in both types of stoichiometry:– step 1 is to write a balanced equation– step 2 is to convert the given quantity into

moles – step 3 is to convert the moles of the given

quantity into moles of the quantity you are looking for

– step 4 is to convert the moles of the quantity you are looking for into the needed variable

this is true in all types of stoichiometry!


• Type 3: Gas Stoichiometry

• You will learn how to do this in our Gases Unit (next unit)

chapter 7 preparation

Documents

lithium chlorate solution

lithium chloride solution

silver nitrate solution

calcium chlorate solution

calcium chloride solution

chromiumii sulfate solution

zinc acetate solution

cesium hydroxide solution