Reactions

Question 1

What bond is broken in the majority of addition reactions?

Answer 1

Pi bond

Question 2

What is hydrogenation and it’s molarity?

Answer 2

Hydrogenation is the breaking of a Pi bond followed by the addition of a hydrogen to each carbon in the bond. One mole of h2 is consumed per Pi bond broken.

Question 3

What is halogenation and it’s molarity?

Answer 3

Halogenation happens through the breaking of Pi bonds and the addition of a molecular Halogen (X2). A halogen atom is added to each carbon in the broken bond. For every mole of broken bonds, one mole of X2 is consumed

Question 4

What is addition of hydracids/protic acids?

Answer 4

The breaking of a Pi bond in reaction with an HX or similar protic acid. In this scenario, the Hydrogen is added to the most saturated carbon in the Pi bond while the conjugate base is added to the remaining carbon.

Question 5

What is the one exception to the Markovnikov rule and what is it called?

Answer 5

HBr in the presence of an organic peroxide catalyst will not obey the Markovnikov rule. In other words, the hydrogen will be attached to the least saturated carbon while the Br will be attached to the most saturated carbon. This is called the Karasch-Mayo rule.

Question 6

What is de-halogenation?

Answer 6

Removal of Halogens from the organic molecule, most often from neighboring carbons and leading to the creation of a Pi bond. In case the halogens are separated by more than 3 carbons, there is a tendency for the chain to convert into a cyclo.

When de-halogenation happens in the reaction between two different compounds, the receiver compound becomes an inorganic product while the donating compound remains organic.

Question 7

What is dehydrohalogenation?

Answer 7

A hydrogen and a halogen in an organic molecule are removed and together form an acid HX. If the halogen and hydrogen are neighbors, they form a Pi bond.

Dehydrohalogenation follows the Saytzeff rule, which is the other side of the Markovnikov rule and states that of the carbons available, the one that is least saturated will lose it’s hydrogen.

Question 8

What is dehydration of alcohols?

Answer 8

Dehydration of alcohols happens when the Hydroxil (-OH) in an alcohol is stripped to form water

This dehydration can happen in two ways, depending on the temperature: Intramolecularly and intermolecularly

Question 9

What is intermolecular dehydration of alcohols?

Answer 9

At lower temperatures (140°C-170°C for primary carbons) dehydration occurs between two equal molecules through the stripping of Hydroxil from one alcohol and the hydrogen of the other’s hydroxil. This creates water and a new organic molecule that contains the remaining structure of both of the original molecules

Question 10

What is intramolecular dehydration of alcohols?

Answer 10

At higher temperatures (170°C + for primary alcohols) the hydroxil of a molecule reacts with a hydrogen from a neighboring carbon to form water and leaves behind a Pi bond

Question 11

What is hydration of alkenes?

Answer 11

Hydration of Alkenes operates very much like the addition of hydracids/protic acids, and follows the Markovnikov rule

for every h2o molecule, a pi bond is broken in the alkene being hydrated, the hydrogen will bind to the carbon with the highest saturation and the hydroxil (-OH) will bind to the remaining carbon

Question 12

What is the proper way to see water in organic chemistry?

Answer 12

In Organic Chemistry, it is useful to think of Water as hydrogen + Hydroxil (H-OH)

Question 13

How do intermolecular dehydration reactions operate?

Answer 13

In the INTERMOLECULAR DEHYDRATION of a substance, the reaction always occurs between two molecules of the same substance.

the resulting molecule is always:

Original molecule (minus hydroxil) - Original molecule (minus hydrogen)

the bond is made between the oxygen of one of the molecules and the carbon that lost it’s hydroxil.

Question 14

In substitution reactions with molecules that contain two groups, which group will be attached to the new molecule?

Answer 14

The most positively charged one

Question 15

What is the hydrogen replacement rule for substitution reactions?

Answer 15

The priority of removal of a hydrogen is related to how saturated it’s carbon is. The more saturated the carbon, the more strongly it’s hydrogens will resist removal.

Question 16

What are halogenation substitution reactions?

Answer 16

In a halogenation substitution reaction, an X2 molecular halogen is split up, one of the atoms then replaces a hydrogen in the base molecule, while the remaining halogen bonds with the removed hydrogen to create a hydracid

Question 17

What is the pattern for substitution reactions using hydroxil-containing molecules as a secondary reagent?

Answer 17

Any molecule that contains the hydroxil group, when utilized as the replacement molecule in a substitution reaction, will be divided between hydroxyl (negative, thus hydroxide) and the remaining atoms of the molecule, which will then replace a hydrogen in the base molecule

the remaining hydroxyl then bonds with the replaced hydrogen to form water.

Question 18

What is the positioning nomenclature for Benzene rings?

Answer 18

Immediately adjacent to main group: Ortho
Second carbon from the main group: Meta
Third carbon/opposite carbon from the main group: Para

Question 19

What are the 6 main properties of redox?

Answer 19

1 - Oxygen is always -2
2 - Hydrogen is always +1
3 - Elements are always 0
4 - Oxidation number of monoatomic ions is the charge of the Ion
5 - Oxidation numbers of a neutral molecule must add up to zero
6 - for polyatomic ions the oxidation number must add up to the charge of the ion

Question 20

What is Alkylation of an aromatic ring?

Answer 20

In the case of an R-X substitution molecule (Hydrocarbon-Halogen, also known as an Alkyl-Halide) the hydrocarbon chain (alkyl) is positively charged, while the halogen is negatively charged, this leads to the alkyl (R) being the substitute for a hydrogen in the aromatic ring. The remaining byproduct of this reaction is the removed hydrogen + the halogen, thus creating a hydracid (HX).

Question 21

What is Alcylation?

Answer 21

In the case of an Acyl (R-C=O-) group attached to a halogen (Acyl-Halide) (R-(C=O)-X) (Hydrocarbon chain connected to a halogen by a Carbonyl) once gain the Halogen (X) is the negative element while the rest of the molecule, the acyl group, is positively charged, thus, the halogen is left over while the acyl group substitutes the hydrogen within the base molecule, the removed hydrogen then binds with the halogen to create a hydracid (HX). The bonding between the acyl and the primary molecule happens at the central carbon of the acyl group (the one double-bonded to the oxygen)

Question 22

What determines the outcome of substitution reactions on Benzene rings?

Answer 22

The presence of ortho-para and meta-directive groups

Ortho-paradirective groups are always saturated and posess exclusively sigma bonds. These prioritize substitution into the Ortho position

Meta-directive groups always have at least one Pi bond and prioritize the meta position

Question 23

What is the broad definition of redox reactions in organic chemistry?

Answer 23

In the context of organic chemistry, Oxidation may be defined simply as the increase in the amount of Oxygen, or, the reduction in the amount of hydrogen. more generally for chemistry, oxidation is the increase in the oxidation state of an atom or loss of electrons

Increases in the number of bonds to the same oxygen atom are considered increases in oxygen amount
Reduction, on the other hand, is the receival of electrons, or, in the context of organic chemistry, an increase in the amount of Hydrogen

Question 24

Which section of a molecule must be analyzed during a redox reaction?

Answer 24

The oxidation state of the functional group being oxidized is the most relevant one

Question 25

Oxidation of Alcohols order

Answer 25

Primary Alcohol:

Alcohol -> Aldehyde -> Carboxylic acid

Secondary Alcohol:

Alcohol -> Ketone

Tertiary Alcohol:

Does not get oxidized

Question 26

What’s a Branda alkene oxidation reaction?

Answer 26

A Pi bond is broken in the Alkene, allowing two hydroxils to bind to the molecule, creating a vicinal dialcohol.

Question 27

What’s an Energic alkene oxidation reaction?

Answer 27

It’s a reaction in which the double bond in the alkene is fully broken, leading to new molecules whose structures will depend on the nature of the carbon present in the double-bond

primary carbons will generate CO2 and H2O

secondary carbons will generate a carboxylic acid

tertiary carbons will generate a ketone

Question 28

What is a common combination that makes for good oxidizing agents?

Answer 28

Molecules with a high amount of oxygen paired with a metal that has a high oxidation state (oxidation number)

Question 29

What is Ozonolysis?

Answer 29

In Ozonolysis, an Ozone molecule (O3) cleaves a double or triple bond in a carbon chain, splitting the organic molecule in two and adding a carbonyl to each of the carbons previously in the bond.

Question 30

Which substance can be added to an Ozonolysis reaction to prevent the creation of carboxylic acids?

Answer 30

Zinc

Question 31

What is the order of Carboxyl reduction reactions?

Answer 31

The inverse of Alcohol oxidation reactions.

Carboxylic acid > Aldehyde > Alcohols.

Question 32

What is the reduction reaction of nitro-compounds?

Answer 32

The replacement of oxygen in the nitro functional group (NO2) with hydrogen, thus creating an amine. (NHn)

Question 33

What is the nitrile/cyano compound reduction reaction?

Answer 33

Both Pi bonds in the nitrile (C≡N) are broken and two hydrogens are added to the carbon and two to the nitrogen. This turns the N side of the group into an Amine.

Question 34

What is a protein?

Answer 34

A protein is a sequence of amino-acids.

Proteins are bio-polymers and aminoacids are bio-monomers

Question 35

What is a peptide bond?

Answer 35

A peptide bond is a bond between two different amino-acids that happens in the following manner:

The carboxyl in one aminoacid gets dehydrated by a hydrogen in the other aminoacid’s amine. This creates water and creates a bond between the carboxyl carbon (now without it’s hydroxil) to the amine nitrogen (now with one less hydrogen)

the resutling functional group (O=C-N) is called amide, with a D.