Types of Chemical Reactions Section 8.2 synthesis reaction combustion reaction decomposition...

Types of Chemical Reactions

Section 8.2

synthesis reaction

combustion reaction

decomposition reaction

single-replacement reaction

double-replacement reaction

precipitate

Section 8.2 Classifying Chemical Reactions

• Classify chemical reactions.

metal: an element that is a solid at room temperature, a good conductor of heat and electricity, and is generally shiny

• Identify the characteristics of different classes of chemical reactions.

Classifying Chemical Reactions

Key Concept 8: There are four types of chemical reactions: synthesis, combustion, decomposition, and replacement reactions.


Type of Reaction:

Synthesis reaction

Explanation: Reaction in which two or more simpler substances (elements) react to produce a single product ( compound).

Types of Chemical Reactions (cont.)

• Other: When two elements react, the reaction is always a synthesis reaction.

General Equation:

A + B AB


Type of Reaction:

Combustion Reaction

Explanation: Reaction where oxygen combines with a substance (normally contains carbon) and releases energy in the form of heat and light.

Types of Chemical Reactions (cont.)

General Equation:

___ + O2 H2O + CO2

CH4 (g) + O2 (g) CO2 (g) + H2O (g)


Type of Reaction:

Decomposition Reaction

Explanation: Reaction in which a single compound breaks down into two or more elements or new compounds.

Decomposition Reactions

• Other: Decomposition reactions often require an energy source, such as heat, light, or electricity, to occur.

General Equation:

AB A + B


Correctly Identify the type of reaction:S = synthesis D = decomposition C = combustion

1. NH3+ H2SO4 (NH4)2SO4

2. C5H9O + O2 CO2 + H2O

3. H2 + O2 H2O

4. NH4OH NH3 + H2O

5. KClO3 (s) KCl (s) + O2 (g)

6. Al (s) + S (s) Al2S3 (s)

7. NaNO3 (s) NaNO2 (s) + O2 (g)

8. CO (g) + O2 (g) CO2 (g)

9. CH4 (g) + O2 (g) CO2 (g) + H2O (g)

10.Mg + N2 Mg3N2


Type of Reaction:

Single Replacement

Explanation: Reaction in which the atoms of one element replace the atoms of another element in a compound.

Replacement Reactions

General Equation:

A + BX AX + B

• Other Info: A metal will not always replace a metal in a compound dissolved in water because of differing reactivates.

• An activity series can be used to predict if reactions will occur.

Hydrogen gas goes here


• Write a balanced chemical equation for each single-replacement reactions involving metals.

• Zn (s) + AgNO3 (aq)

• Zn(s) + H2SO4 (aq)

• Na(s) + H2O(l)


• Write a balanced chemical equation for each single-replacement reactions involving halogens

• Cl2 (g) + HBr(aq)

• I2 + HCl2 (aq)

•Simulations


Type of Reaction:

Double Replacement

Explanation: Reaction in which the ions exchange between two compounds.

Replacement Reactions (cont.)

General Equation:


• Other: The solid product produced during a chemical reaction in a solution is called a precipitate.

• All double replacement reactions produce either water, a precipitate, or a gas.


• This table shows the steps to write double replacement reactions.


• Write a balanced chemical equation for each double-replacement reactions

BaCl2(aq) + K2CO3 (aq) (a precipitate of barium carbonate is formed)

FeS (s) + HCl (aq) (Hydrogen sulfide gas is formed)

Get out your practice problems.

A. AB. BC. CD. D

Section Assessment

Which of the following is NOT one of the four types of reactions?

A. deconstructive

B. synthesis

C. single replacement

D. double replacement

A. AB. BC. CD. D

Section Assessment

The following equation is what type of reaction?

KCN(aq) + HBr(aq) → KBr(aq) + HCN(g)

A. deconstructive

B. synthesis

C. single replacement

D. double replacement

Solution

Everyday definition• Answer to a problem• A type of liquid

Chemistry• Key Concept 14:

Solution- uniform mixture that can contain solid, liquid, or gases

Solution = Homogenous mixtureThey are synonyms

How a solution is made?

• Solution consist of a solvent and solute.

• Key Concept 15: Solvent- the substance that dissolves the solute to form a solution; most plentiful substance in the solution.

• Key Concept 16: Solute- one or more substance dissolved in a solution.

• Dissociation

• Solubility is physical properties.– Physical properties are those properties that can be

observed or measured without affecting the composition of the sample.

• Key Concept 17: Solubility is the maximum quantity of a substance that may be dissolved in another. The maximum amount of solute that may be dissolved in a solvent.

Solubility

Effect of Temperature on Solubility

Solubility• depends on temperature• of most solids increases as temperature

increases• of gases decreases as temperature

increases• What is sodium chlorides solubility?

– Water: 359 g/L– Ammonia: 21.5 g/L– Methanol: 14.9 g/L

White Solid

Water + universal indicator

Water (at room

temperature)HCl Methanol Iodine

Temp of solubility in

water

Baking Soda

GreenSlightly soluble

Produces gas

Insoluble ---------- 50 C

SugarYellow-orange

Soluble ---------- InsolubleTurns blue

20 C

Benzoic Acid

Pink Insoluble ---------- Soluble ---------- 100 C

Flour Orange Insoluble ---------- InsolubleTurns blue

insoluble

Sodium Chloride

Orange soluble ----------Slightly soluble

---------- 20 C

•30

Soluble and Insoluble Salts

Key Concept 18: Ionic compounds that

• dissolve in water are soluble salts

• do not dissolve in water are insoluble salts

•31

Equations for Forming Solids

A full equation shows the formulas of the compounds.Pb(NO3) 2(aq) + 2NaCl(aq) PbCl2(s) + 2NaNO3(aq)

An ionic equation shows the ions of the compounds.Pb2+(aq) + 2NO3

−(aq) + 2Na+(aq) + 2Cl−(aq)

PbCl2(s) + 2Na+(aq) + 2NO3−(aq)

Key Concept 19: A net ionic equation shows only the ions that form a solid.

Pb2+(aq) + 2Cl−(aq) PbCl2(s)

Quick Demo: DR Visual

Lead (II) Nitrate Sodium ChloridePb(NO3) 2 2NaCl

1. How do I make an solution?2. What is the solvent and the solute?3. What happens during dissociation?4. What happens in a double replacement reaction?

Pb(NO3) 2 (aq) + 2NaCl(aq) PbCl2(s) + 2NaNO3(aq)

Part 1:(2.5 pts) Purpose: To determine whether or not a reaction occurs and to predict the products of a reaction.

Title: Determining Solubility to Solve Double Replacement Reaction (70 pts)

(7.5 pts) Safety:• We are working with acids; gloves, goggles, and aprons must

be worn properly at all times.• All chemicals must be disposed of in specified waste beakers

in the fume hoods. These chemicals are toxic and will harm the environment if not disposed of properly.

• Do not eat, drink, or apply the chemicals to skin. Many of these chemicals are highly corrosive and in addition to being toxic, they will burn your skin and muscle tissue. Ouch!

• If any of the chemicals get on your skin/eyes you MUST wash exposed area for 15 minutes in eye wash/shower.

Title: Determining Solubility to Solve Double Replacement Reaction

(10 pts) Data Table and Results


Beginning

Nitrate

HCl

added

H2SO4

added

NaOH

added

LiNO3

KNO3

Mg(NO3)2

Ca(NO3)2

Co(NO3)2

Cu(NO3)2

AgNO3

Pb(NO3)2

(10 pts) Part 2-1. All nitrate salts are __________.2. Most salts containing ______ and ________ cations are

soluble. 3. All cations from ______________ are soluble. In addition NH4

+1 salts are soluble.

4. Salts with halogen anions are usually _____________.5. Most sulfate salts are __________. Exceptions include the

cations __________ and ____________. 6. Hydroxides are usually ___________ except those containing

cations from __________.


(20 pts) Part 3-1.-11. that you will need to answer in your lab notebook by predicting products of the double replacement reaction.

( 20) Part 4-Correctly using solubility tables and charts


Types of Chemical Reactions Section 8.2 synthesis reaction combustion reaction decomposition...

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