Chemistry B Unit 5

Why does a carbon atom form four covalent bonds?

Carbon has four valence electrons, so a carbon atom always forms four covalent bonds.

How did the study of organic chemistry begin?

Less than 200 years ago, it was believed that only living organisms could synthesise the carbon compounds found in their cells. The study of these compounds was known as organic chemistry. Most people thought that a mysterious vital force directed the for

What is the simplest organic compound?

Hydrocarbon.

What is a hydrocarbon?

An organic compound that contains only carbon and hydrogen.

What are the two simplest hydrocarbons?

Methane and ethane.

What is methane?

CH4. The major component of natural gas. Formed by the action of bacteria on decaying plants in swamps and other marshy areas giving it the name marsh gas. Livestock and termites emit substantial quantities of methane as a product of digestion. Not typica

What is ethane?

CH6. Carbon-carbon bond in ethane, making it more typical than methane. Two carbons share a pair of electrons, and the remaining six valence electrons form bonding pairs with the electrons from six hydrogen atoms.

Why can carbon form so many different compounds?

Its ability to form stable carbon-carbon bonds.

What are the properties of hydrocarbons?

The electrons pair in a carbon-hydrogen bond or a carbon-carbon bond is shared equally between the nuclei of the atoms. Meaning that hydrocarbons are nonpolar molecules. The attractions between nonpolar molecules are weak van der Waals forces. So hydrocar

What are two possible arrangements of carbon atoms in an alkane?

The carbon atoms in an alkane can be arranged in a straight chain or in a chain that has branches.

What is an alkane?

an alkane is a hydrocarbon in which there are only single covalent bonds. In any alkane, all the carbon-carbon bonds are single covalent bonds, and all the other bonds are carbon-hydrogen bonds. Methane and ethane are alkanes.

What are straight-chain alkanes?

Ethane is the simplest straight-chain alkane. A straight-chain alkane is any alkane that contains any number of carbon atoms, one after the other, in a chain. Propane (C3H8) has three carbon atoms bonded in a chain with eight electrons shared with eight h

What are the properties of straight-chain alkanes?

Straight-chain alkanes are a homologous series. A group of compounds forms a homologous series if there is a constant increment of change in molecular structure from one compound in the series to the next. A CH2 group is the increment of change in straigh

How do you name straight-chain alkanes?

The names of straight-chain alkanes follow rules established by the International of Pure and Applied Chemistry (IUPAC). Every alkane has a name that ends with the suffix -ane. For straight-chain alkanes with one to four carbon atoms, the official names a

How do you draw structural formulas for straight-chain alkanes?

Write the symbol for carbons are many times as necessary to get the proper chain length. Complete the formula with hydrogens and lines representing covalent bonds. Complete structural formulas show all the atoms and bonds in a molecule. In a condensed str

What are branched-chain alkanes?

A carbon atom can form three or even four carbon-carbon bonds, resulting in a branched chain. In organic chemistry, branches on a hydrocarbons chain are discussed as if they were substituted for a hydrogen atom on the chain. An atom or group of atoms that

How are alkyl groups named?

Remove the -ane ending from the parent hydrocarbon and add the ending -yl.

What are the three smallest alkyl groups?

Methyl, ethyl, and propyl.

How are branched-chain alkanes formed?

When a substituent alkyl group is attached to a straight-chain hydrocarbon, branches are formed. An alkane with one or more alkyl groups is called a branched-chain alkane. Each cabron molecule can be categorised as a primary, secondary, tertiary, or quate

What is isooctane?

A hydrocarbon that contains each of the four types of carbons. It is used to determine octane ratings of mixtures of hydrocarbons that make up gasoline. Gasoline's octane rating is a measure of its ability to prevent engine knock.

How do you name branched-chain alkanes?

The IUPAC rules are used. The name of a branched-chain alkane is based on the name of the longest continuous carbon chain. Each substituent is named according to the length of its chain and numbered according to its position on the main chain.
1. Find the

How do you draw structural formulas for branched-chain alkanes?

First, find the root word (ending in -ane). Draw the longest carbon chain to create the parent hydrocarbon. Identify the substituent groups in the hydrocarbon name. Attach the substituents to the numbered parent chain at the proper positions. Complete the

What are the hydrocarbon prefixes and suffixes?

Number of carbon atoms --> prefix
1 --> meth-
2 --> eth-
3 --> prop-
4 --> but-
5 --> pent-
6 --> hex-
7 --> hept-
8 --> oct-
9 --> non-
10 --> dec-
Number of bonds between carbon atoms --> suffix
single --> -ane
double --> -ene
triple --> -yne

What are the structural characteristics of alkenes?

At least one carbon-carbon bond in an alkene is a double covalent bond. Other bonds may be single carbon-carbon bonds and carbon-hydrogen bonds.

What is a saturated compound?

An organic compound that contains the maximum number of hydrogen atoms per carbon atom. Alkanes are saturated compounds because only bonds in alkanes are single covalent bonds.

What is an unsaturated compound?

An organic compound that contains double or triple carbon-carbon bonds. The ratio of hydrogen atoms to carbon atoms is lower in an unsaturated compound than in a saturated compound. Alkenes and alkynes are unsaturated compounds.

What is an alkene?

A hydrocarbon that contains one or more carbon-carbon double covalent bonds. A carbon-carbon double bond is shown in structural formulas as tow parallel lines.

What is the simplest alkene?

Ethene (ethylene).

How do you name an alkene using the IUPAC system?

1. Find the longest chain in the molecule that contains the double bond. This chain is the parent alkene.
2. It has the root name of the alkane with the same number of carbons plus the ending -ene.
3. The chain is numbered so that the carbon atoms of the

What are the structural characteristics of alkynes?

At least one carbon-carbon bond in an alkyne is a triple covalent bond. Other bonds may be single or double carbon-carbon bonds and carbon-hydrogen bonds.

What is an alkyne?

A hydrocarbon that contains one or more carbon-carbon triple covalent bond. A carbon-carbon triple bond is shown in structural formulas as three parallel lines. Alkynes, like alkenes, are unsaturated.

What is the simplest alkyne?

Ethyne (C2H2) also called acetylene. Ethyne is burned in oxy-acetylene torches used for welding.

What are the properties of alkynes and alkenes?

Major attractions are van der Waals forces. The introduction of a double or triple bond into a hydrocarbon has no effect on physical properties such as boiling point. Alkenes have the highest boiling point, followed by alkanes, followed by alkynes.

How do the properties of constitutional isomers differ?

Constitutional isomers differ in physical properties such as boiling point and melting point. They also have different chemical reactivities.

What are isomers?

Compounds that have the same molecular formula but different molecular structures.

What are constitutional isomers?

Constitutional isomers (structural isomers) are compounds that have the same molecular formula, but the atoms are joined together differently.

How are hydrocarbon isomer boilings points compared?

The more highly branched hydrocarbon structure will be the isomer with the lower boiling point.

What is an example of a constitutional isomer?

Butane and 2-methylpropane.

What are two types of stereoisomers?

Cis-trans and enantiomers.

What is a stereoisomer?

Molecules that have the same molecular formula, the atoms are joined in the same order, but the positions of the atoms are different.

What is a cis-trans isomer?

Double bonds between two carbon atoms prevents other atoms from rotating and spinning with respect to each other. Due to the lack of rotation, groups on either side of the double bond can have different orientations. Cis-trans isomers can occur in other m

What is an asymmetric carbon atom?

A carbon atom with four different atoms bonded to it.

What are enantiomer isomers?

Occurs whenever a central atom (usually carbon) has four different atoms bonded to it. In other words it occurs when there is an asymmetric atom. (Remember, sometimes the terms right-handed and left-handed are used to describe molecules with an asymmetric

What is the general structure of a cyclic hydrocarbon?

In some hydrocarbon compounds, the carbon chain is in the form of a ring.

What is a cyclic hydrocarbon?

A compound that contains a hydrocarbon ring.

What are the most abundant hydrocarbon rings?

Rings with 5 or 6 carbons.

What is a cycloalkane?

A cyclic hydrocarbon that contains only single bonds, and is saturated.

How do you name a cycloalkane using IUPAC rules?

1. Count the number of carbons in the ring and assign the corresponding alkane name.
2. Add the prefix cyclo- to the alkane name.

What is the most accurate description of bonding in benzene?

In a benzene molecule, the bonding electrons between carbon atoms are shared evenly around the ring.

What is an aromatic compound?

Also known as an arena, is an unsaturated compound that contains a benzene ring or other ring in which the bonding like that of benzene.

What is the simplest aromatic compound?

Benzene.

What is an aliphatic compound?

Any compound that is not aromatic, including alkane, alkenes, alkynes, and cycloalkane.

What is the structure of benzene?

Friedrich Kekul� (1829-1896) made a major contribution to chemistry. He was the first to describe the structure of a benzene molecule. The benzene molecule is a six-membered carbon ring with one hydrogen atom attached to each carbon. This arrangement leav

What is the most accurate description of bonding in benzene?

In a benzene molecule, the bonding electrons between carbon atoms are shared evenly around the ring. In an extreme example, there are 3 extreme double bonds and 3 extremes single bonds. Usually all the bonds are hybrids between single and double bonds. Th

What are substitute the aromatic compounds?

Many dyes used to produce colors in clothing are substituted aromatic compounds. Compounds containing substitute to attached to a benzene ring are named using benzene as the parent hydrocarbon. When the benzene ring is a substitute the, the C6H5 group is

How do you name aromatic compounds?

The possible positions of the two substituents are designated as 1,2; 1,3; or 1,4. Common names of disubstituted benzene use the terms ortho, meta, and para in place of numbers.

What hydrocarbons are in natural gas?

Natural gas is an important source of alkanes of low molar mass. Composed of 80% methane, 10% ethane, 4% propane, and 2% butane. The remaining 4% is nitrogen and hydrocarbons of a higher molar mass. Natural gas contains a small amount of helium. Natural g

What characterizes the complete combustion of hydrocarbons?

A blue flame will appear with the complete combustion of hydrocarbons. A yellow flame appears due to the formation of small, glowing carbon particles that are deposited as soot when they cool in incomplete combustion. Carbon monoxide forms with carbon dio

What is petroleum?

The organic compounds found in petroleum, or crude oil, are more complex than those in natural gas. Most hydrocarbons found in petroleum are straight-chain and branched-chain alkanes. Petroleum also contains small amounts of aromatic compounds and sulfur-

What is the first step in the refining of petroleum?

Petroleum refining begins with the distillation of crude oil into fractions according to boiling point.

What are some other steps in refining petroleum?

Gasoline makes up only 40% of petroleum, but is the most widely used petroleum product. So people use cracking. Cracking is the controlled process by which hydrocarbons are broken down or rearranged into smaller, more useful short-chain components of gaso

What is bioremediation?

Microbes, typically bacteria, eat oil to clean up oil spills. During the digestion process, the oil is converted to carbon dioxide and water.

What characteristics are used to classify coal?

Goal is classified by its hardness and carbon content.

How is coal formed?

First, peat is formed. Peat is a soft, brown, spongy, fibrous material. When first dug out of bogs, peat has a high water content. After drying, it produces a low-cost but smoky fuel. If peat is left in the ground, it continues to change. After a long tim

How is coal harvested?

In North America, people use strip mines as the coal lies 1 to 3 meters under the ground. Europe and Asia use underground mines as the coal lies 1000 to 1500 meters below Earth's surface.

What is the composition of coal?

Coal consists largely of condensed aromatic compounds of extremely high molar mass. These compounds have a high proportion of carbon compared with hydrogen. Due to the proportion of aromatic compounds, coal leaves more soot when burned than the more aliph

How are organic compounds classified?

Organic compounds can be classified according to their function groups.

How are there so many different organic molecules when hydrocarbon chains and rings are inert (do not react)?

Substituent groups attach to hydrocarbon rings or chains. The substituents often contain oxygen, nitrogen, sulfur, and phosphorus. They are call functional groups because they are the chemically functional parts of the molecules. Most organic chemistry in

What is a functional group?

A functional group is a specific arrangement of atoms in an organic compound that is capable of characteristic chemical reactions.

What are organic compounds classified by each functional group?

(R is any hydrocarbon. List compound type, then general structure, then functional group.)
halocarbon --> R-X (X=F, Cl, Br, or I) --> Halogen
alcohol --> R-OH --> hydroxy
ether --> R-O-R --> ether
amine --> R-NH2 --> amino
O
||
aldehyde --> R-C-H --> carb

What is the general formula of a halocarbon?

The general formula of a halocarbon is RX, where X is a halogen substituent.

What is a halocarbon?

An organic compound that contains at least one covalently bonded fluorine, chlorine, bromine, or iodine atom.

What are the IUPAC rules for naming halocarbons?

They are based on the name of the parent hydrocarbon. Halogen groups are named as substituents.
Common names of halocarbons consist of two parts. The first part names the hydrocarbon portion of the molecule as an alkyl group. The second part names the hal

What are some properties of halocarbons and where are they found?

The attractions between halocarbon molecules are primarily the result of the weak van der Waals interactions. These attractions increase with the degree of halogen substitution. Meaning that more highly halogenated organic compounds have higher boiling po

How are substitution reactions used in organic chemistry?

Substitution reactions are an important method of introducing new functional groups to organic molecules.

What is different between inorganic and organic reactions?

Organic reactions take longer because they involve the breaking of strong covalent bonds. They require catalysts, whereas inorganic reactions do not. Organic reactions are complex and give a mixture of products that have to be separated by distillation, c

What is a common organic reaction? Give an example.

Substitution reactions. A halogen atom replaces a hydrogen atom on an alkane to produce a halocarbon. This is a halogenation reaction because it introduces a halogen atom into the molecule. Sunlight or another source of ultraviolet radiation serves as a c

What is the halogenation of benzene?

A halogen substitutes a hydrogen atom on the benzene ring. Iron compounds are the catalysts for the reactions in aromatic compounds.

What is the formation of an alcohol from a halocarbon?

R-X + OH- --> R-OH + X-
Chemists usual use potassium hydroxide as the source of hydroxide ions.

What is the general formula of an alcohol?

The general formula of an alcohol si R-OH

What is an alcohol? What are the parts of an alcohol

An organic compound with an -OH group. The -OH is called a hydroxy group, or hydroxyl group. The oxygen atom has two pairs of nonbonding electrons, which compresses the R-O-H bond angle. As a result, an alcohol functional group has a bent shape.

How are aliphatic alcohols classified into structural categories?

Aliphatic alcohols can be classified into structural categories according to the number of carbons attached to the carbon with the hydroxyl group. If only one carbon (or no carbon) is attached to C-OH, the latter carbon is considered a primary carbon, and

How do you name alcohols?

Both IUPAC and common names are used for alcohols. To name aliphatic alcohols using the IUPAC system, drop the -e ending of the parent hydrocarbon name and add the ending -ol. The parent hydrocarbon is the longest continuous chain of carbons that includes

What are the properties of alcohols?

Alcohols are capable of intermolecular hydrogen bonding, which is reflected in their physical properties. Alcohols boil at higher temperatures than alkanes and halocarbons containing a comparable number of atoms. Because alcohols are derivatives of water

What are the uses of alcohols?

Alcohols like 2-propanol, can be used as disinfectants and antiseptics. It is used as a base for perfumes, creams, lotions, and other cosmetics. Another alcohol, 1,2,3-popanetriol, is highly soluble in water because it has three hydroxy groups. It has the

How are addition reactions used in organic chemistry?

Addition reactions are an important method of introducing new functional groups to organic molecules. They are used to convert alkenes to alkanes.

What is an addition reaction?

The double bonds of alkenes are easier to break than single bonds of alkanes. It is possible for a compound of general structure X-Y to add to a double bond. In an addition reaction, a substance is added at the double or triple bond of an alkene or alkyne

What is a hydration reaction?

The addition of water to an alkene is a hydration reaction. A hydration reaction results in the formation of an alcohol. Hydration reactions usually occur when the alkene and water are heated to about 100�C100�C 100 standard cap c in the presence of a sma

What are halogenation reactions?

When the reagent X�YX�Y cap x em dash cap y is a halogen molecule such as chlorine or bromine, the product of the reaction is a disubstituted halocarbon. The addition of bromine to ethene to form the disubstituted halocarbon 1,2-dibromoethane is an exampl

What are hydrogenation reactions?

The addition of hydrogen to a carbon-carbon double bond to produce an alkane is called a hydrogenation reaction. Hydrogenation usually requires a catalyst. A platinum (Pt) or palladium (Pd) catalyst is often used. The manufacture of margarine or spreads f

What is the general formula of an ether?

The general formula of an ether is R-O-R.

What is an ether?

an ether is an organic compound in which oxygen is bonded to two carbon groups. Like an alcohol, an ether molecule is bent because of the unshared pairs of electrons on the oxygen atom.

How do you name an ether using the IUPAC system?

To name an ether using the IUPAC system, first you need to identify the two R groups. The smaller R group is treated as part of the substituent and the -ane or -ene ending is replaced with -oxy. The larger R group is the parent hydrocarbon. In the common

What is important about diethyl ether and dipheynyl ether?

It was the first reliable general aesthetic. Doctors used it for more than a century. However, because diethyl ether is highly flammable and often causes nausea, it was replaced by other anesthetics such as isoflurance. Diphenyl ether is used in the manuf

What are some properties of ethers?

Ethers usually have lower boiling points than alcohols of comparable molar mass, but higher boiling points than comparable hydrocarbons and halocarbons. Unlike alcohols, ethers are not capable of forming hydrogen bonds with other ether molecules. The oxyg

What is the general formula of an amine?

The general formula fo an amine is RNH2, R2NH, or R3N.

What is an amine?

An amine is an organic compound in which nitrogen is bonded to a carbon group. Amines are similar to ammonia (NH3). When one, two, or three of the hydrogens in ammonia are replaced by carbon groups, the compound is classified as an amine.

How are amines classified structurally?

Amines can be classified according to the number of R groups attached to the nitrogen atom. An amine with the general formula RNH2 is a primary amine because one R group is attached to the nitrogen atom. Amines with two and three R groups attached to the

How do you name amines?

The IUPAC system for naming primary amines is similar to that of alcohols. The -e ending of the parent hydrocarbon is changed to -amine. For example, CH3NH2 is named methanamine. The common names of primary amines are similar to the IUPAC names. The alkyl

What are some properties of amines?

Like alcohols, primary amines form intermolecular hydrogen bonds. Because nitrogen is less electronegative than oxygen, the hydrogen bonds in amines are not as strong as those of alcohols. As a result, primary amines have lower boiling points than alcohol

What structural characteristic do an aldehyde and a ketone share?

The C==O functional group is present in aldehydes and ketones.

What is a carbonyl group?

Remember that in an alcohol, an oxygen atom is bonded to a carbon group and a hydrogen atom. In an ether, an oxygen atom is bonded to two carbon groups. An oxygen atom can also be bonded to a single carbon atom by a double covalent bond. Such an arrangeme

What is an aldehyde and a ketone?

An aldehyde is an organic compound in which the carbon of the carbonyl group is joined to at least one hydrogen. The general formula of an aldehyde is RCHO. A ketone is an organic compound in which the carbon of the carbonyl group is joined to two other c

What is the IUPAC system for naming aldehydes and ketones?

The IUPAC system may be used for naming aldehydes and ketones. For either class of compounds, first identify the longest carbon chain that contains the carbonyl group. Replace the -e ending of the parent structure with -al to designate an aldehyde. In the

What are some uses of aldehydes and ketones?

The simplest aldehyde is methanal (HCHO), also called formaldehyde. Methanal is very important industrially. Its greatest use is in the manufacture of synthetic resins. Methanal is usually available as a 40% aqueous solution, known as formalin. Formalin c

What are some properties of aldehydes and ketones?

Aldehydes and ketones cannot form intermolecular hydrogen bonds because they lack �OH and �NH groups. Consequently, they have boiling points that are lower than those of corresponding alcohols. Aldehydes and ketones can attract each other, however, throug

What is the general formula for a carboxylic acid?

The general formula for a carboxylic acid is RCOOH.

What is a caboxyl group?

A carboxyl group is a functional group that consists of a carbonyl group attached to a hydroxy group. It can be written as �COOH or �CO2H.

What are carboxylic acids?

As you may have guessed from their name, carboxylic acids are acidic. Carboxylic acids are considered weak acids because they ionize weakly in solution. In water, they can lose a hydrogen ion and form a carboxylate ion, as shown in the following reaction.

How do you name carboxylic acids?

In the IUPAC system, carboxylic acids are named by replacing the -e ending of the parent structure with the ending -oic acid. Remember, the parent hydrocarbon of a carboxylic acid is the longest continuous carbon chain containing the carboxyl group. So, f

What are the bonds of carboxylic acids?

Like alcohols, carboxylic acids form intermolecular hydrogen bonds. Thus, carboxylic acids have higher boiling and melting points than other compounds of similar molar mass. The low-molar-mass members of the aliphatic carboxylic acid series are colorless,

Why is dehydrogenation classified as an oxidation reaction?

Dehydrogenation is an oxidation reaction because the loss of each molecule of hydrogen involves the loss of two electrons from the organic molecule.

How does oxidation-reduction reactions relate to organic chemistry?

In organic chemistry, the number of oxygen atoms and hydrogen atoms attached to carbon indicates the degree of oxidation of a compound. The fewer hydrogens on a carbon-carbon bond, the more oxidized the bond. Thus, a triple bond is more oxidized than a do

What is the general formula of an ester?

The general formula of an ester is RCOOR.

What is an ester?

Esters are probably the most pleasant and delicious organic compounds one can study. Many esters have pleasant, fruity odors. Esters give blueberries, pineapples, apples, pears, bananas, and many other fruits their characteristic aromas. They also give ma

How does an addition polymer form?

An addition polymer forms when unsaturated monomers react to form a polymer.

What is a polymer?

Most of the reactions that you have learned about so far involve reactants and products of low molar mass. Some of the most important organic compounds that exist, however, are giant molecules called polymers. Each day, you see many different polymers. Fo

How are condensation polymers formed?

Condensation polymers are formed by the joining of monomers with the loss of a small molecule such as water.

What are condensation polymers?

The formation of a polyester is a common example of condensation polymerization. Condensation polymers are formed by the joining of monomers with the loss of a small molecule such as water. Polyesters are polymers that consist of many repeating units of d

What is an amino acid?

Many biological compounds contain nitrogen in addition to carbon, oxygen, and hydrogen. Some of the most important nitrogen-containing molecules in organisms are amino acids. In fact, the polymers of amino acids make up more than one half of the dry weigh

What is the general structure of an amino acid?

Amino acids consist of a carboxyl group, an amino group, a hydrogen, and an R group side chain that are all covalently bonded to a central carbon atom.

What determines the differences in the chemical and physiological properties of peptides and proteins?

Differences in the chemical and physiological properties of peptides and proteins result from differences in the amino acid sequence.

What are peptides and proteins?

A peptide is any combination of amino acids in which the amino group of one amino acid is united with the carboxyl group of another amino acid. The amide bond between the carboxyl group of one amino acid and the nitrogen in the amino group of the next ami

How do enzymes affect the rates of reactions in living things?

Enzymes increase the rates of chemical reactions in living things.

What are enzymes?

Enzymes are proteins that act as biological catalysts. Enzymes increase the rates of chemical reactions in living things. In 1926, the American chemist James B. Sumner reported the first isolation and crystallization of an enzyme. The enzyme he isolated w

How do enzymes work?

Enzymes catalyze most of the chemical changes that occur in the cell. Substrates are the molecules on which an enzyme acts. In a typical enzymatic reaction, shown in Figure 24.10, the substrate interacts with side chains of the amino acids on the enzyme.

What are coenzymes?

Some enzymes can directly catalyze the transformation of biological substrates without assistance from other substances. Other enzymes need nonprotein coenzymes, also called cofactors, to assist the transformation. Coenzymes are metal ions or small organi