Chapter Menu Ionic Reactions Reactions of Organic Compounds Exit Click a hyperlink or folder tab to view the corresponding slides.

Section 22-4 Reactions of Organic Compounds Classify an organic reaction into one of five categories: substitution, addition, elimination, oxidation-reduction, or condensation. catalyst: a substance that increases the rate of a chemical reaction by lowering activation energies but is not consumed in the reaction Use structural formulas to write equations for reactions of organic compounds. Predict the products of common types of organic reactions.

Section 22-4 Section 22.4 Other Reactions of Organic Compounds (cont.) elimination reaction dehydrogenation reaction dehydration reaction Classifying the chemical reactions of organic compounds makes predicting products of reactions much easier. addition reaction hydration reaction hydrogenation reaction

Section 22-4 Classifying Reactions of Organic Substances (cont.) The formation of alkenes from alkanes is an elimination reaction, a reaction in which a combination of atoms is removed from two adjacent atoms forming an additional bond between the two carbon atoms.elimination reaction

Section 22-4 Classifying Reactions of Organic Substances (cont.) A reaction that eliminates two hydrogen atoms is called a dehydrogenation reaction.dehydrogenation reaction

Section 22-4 Classifying Reactions of Organic Substances (cont.) An elimination reaction in which the atoms removed form water is called a dehydration reaction. dehydration reaction

Section 22-4 Classifying Reactions of Organic Substances (cont.) Addition reactions result when other atoms bond to two atoms bonded by a double or triple covalent bonds.Addition reactions A hydration reaction is an addition reaction in which a hydrogen atom and hydroxyl group from a water molecule add to a double or triple bond.hydration reaction

Section 22-4 Classifying Reactions of Organic Substances (cont.) A hydrogenation reaction involves the addition of hydrogen to atoms in a double or triple bond.hydrogenation reaction Catalysts are usually needed in hydrogenation reactions. Hydrogenation reactions are commonly used to convert liquid unsaturated fats into saturated fats that are solid at room temperature.

Section 22-4 Classifying Reactions of Organic Substances (cont.)

Section 22-4 Classifying Reactions of Organic Substances (cont.) Many organic compounds can be converted to other compounds by oxidation-reduction reactions.

Section 22-4 Classifying Reactions of Organic Substances (cont.)

Section 22-4 Predicting Products of Organic Reactions Each type of reaction—substitution, addition, elimination, oxidation-reduction, and condensation—can be used to predict the products of other organic reactions of the same types.

A.A B.B C.C D.D Section 22-4 Section 22.4 Assessment Which type of reaction normally produces an alcohol from an alkene? A.substitution B.elimination C.hydration D.addition

A.A B.B C.C D.D Section 22-4 Section 22.4 Assessment What type of reaction is the following? alkyl halide → alkene A.halogenation B.elimination C.addition D.substitution

Study Guide 4 Section 22.4 Other Reactions of Organic Compounds Key Concepts Most reactions of organic compounds can be classified into one of five categories: substitution, elimination, addition, oxidation-reduction, and condensation. Knowing the types of organic compounds reacting can enable you to predict the reaction products.

A.A B.B C.C D.D Chapter Assessment 4 What is an addition reaction in which a hydrogen atom and hydroxyl group from a water molecule add to a double or triple bond called? A.elimination reaction B.hydration reaction C.dehydration reaction D.hydrogenation reaction

A.A B.B C.C D.D STP 1 What are the products of this reaction? CH 3 CH 2 Br + NaOH → ____ A.CH 3 CH 2 Na + BrOH B.CH 3 CH 2 OH + NaBr C.CH 3 CH 2 OHNaBr D.CH 3 CH 3 + Na 3 BrO

A.A B.B C.C D.D STP 4 What are the oxidation numbers of the elements in H 2 SO 4 ? A.H = +1, S = +6, O = –2 B.H = +2, S = +4, O = –4 C.H = +1, S = +4, O = –1 D.H = +1, S = –10, O = +2

I ONIC R EACTIONS N UCLEOPHILIC S UBSTITUTION AND E LIMINATION R EACTIONS OF A LKYL H ALIDES 1. Nucleophilic Substitution Reactions:

2.A nucleophile, a species with an unshared electron pair (lone-pair electrons), reacts with an alkyl halide (substrate) by replacing the halogen substituent (leaving group). 3.In nucleophilic substitution reactions, the C–X bond of the substrate undergoes heterolysis, and the lone-pair electrons of the nucleophile is used to form a new bond to the carbon atom:

4.When does the C – X bond break? 1)Does it break at the same time that the new bond between the nucleophile and the carbon forms? 2)Does the C–X bond break first? And then

1.A nucleophile is a reagent that seeks positive center. Nucleophiles 2.A nucleophile is any negative ion or any neutral molecule that has at least one unshared electron pair. 1)General Reaction for Nucleophilic Substitution of an Alkyl Halide by Hydroxide Ion

2)General Reaction for Nucleophilic Substitution of an Alkyl Halide by Water i)The first product is an alkyloxonium ion (protonated alcohol) which then loses a proton to a water molecule to form an alcohol

Leaving Groups 1.To be a good leaving group the substituent must be able to leave as a relatively stable, weakly basic molecule or ion. In alkyl halides the leaving group is the halogen substituent –– it leaves as a halide ion. i)Because halide ions are relatively stable and very weak bases, they are good leaving groups. 2.General equations for nucleophilic substitution reactions: or

Specific Examples: 3.Nucleophilic substitution reactions where the substarte bears a formal positive charge:

Mechanism: Step 1 Step 2 Step 3 A Mechanism for the S N 1 Reaction

A Mechanism for the S N 2 Reaction Reaction: Mechanism:

Elimination Reactions of Alkyl Halides D EHYDROHALOGENATION Heating an alkyl halide with a strong base causes elimination to happen: X = Cl, Br, I

The E1 Reaction A Mechanism for the E1 Reaction Step 2 (CH 3 ) 3 CBr + H 2 O CH 2 =C(CH 3 ) 3 + H 2 O + + Cl – Step 1 Reaction:

The E2 Reaction A Mechanism for the E2 Reaction Reaction: C 2 H 5 O – + CH 3 CHBrCH 3 CH 2 =CHCH 3 + C 2 H 5 OH + Br – Mechanism: