Chemistry Unit 4 Topic 1

Name the prefix’s for the number of carbons.

Meth, Eth, Prop, But, Pent, Hex, Hept, Oct, Non, Dec

Function group for Alkene

Carbon to carbon double bond

Functional group for Alkyne

Carbon to carbon triple bond

Functional group for Alcohol

Hydroxyl group (-OH)

Functional group for Ketone

Carbonyl group (C=O)

Functional group for Carboxylic Acid

Carboxyl group (double bond to an O and single bond to an OH)

Functional Group for Haloalkane

Halogen

Functional group for a Ester

Double bond to an O and single bond to an O not connected to a OH or H

Functional group for Nitrile

Triple bond to N

Functional Group for Amine

A single bonded N

Functional Group for Amide

Double bond to O and single bond to N

What is an isomer?

Molecules with the same molecular formula but with the atoms arranged differently

What is a structural isomer?

Same molecular formula, different structural formulas (different bonds connecting the atoms)

What is a stereoisomer?

Molecules with the same molecular formula but different spatial arrangement of atoms

What is a geometric isomer?

Type of stereoisomer that occurs when atoms have different arrangement around a double bond

What is a cis isomer?

The atoms/groups are positioned on the same side

What is a trans isomer?

The atoms/groups are positioned on different sides

What are the three intermolecular forces from strongest to weakest?

Hydrogen bonds, dipole-dipole interactions, dispersion

What do stronger intermolecular forces result in?

Increase in melting point, boiling point, and solubility in water. Decrease in solubility in organic solvents

What is a homologous series?

A sub-category of molecular class where the only difference is the. number of repeating units.

What functional groups only have dispersion forces?

Hydrocarbons: Alkanes, Alkenes, Alkynes

What does a longer chain of carbons mean for the dispersion forces?

Stronger

Which functional groups have dipole-dipole and dispersion forces.

Aldehydes, Ketones, Esters, Amides, Amines, and Nitriles.

Which functional groups have hydrogen bonds, dipole-dipole and dispersion forces.

Carboxylic Acids and Alcohols + Amines and Amides when they form hydrogen bonds.

Adding CH2 will increase or decrease boiling and melting points.

Increase

What is a volatile molecule?

It easily changes from being a solid or liquid to a vapour/gas

Will a volatile liquid have a low or high boiling point?

Low

Are haloalkanes volatile? Why?

Yes, because they are polar and experience dipole-dipole forces which are not very strong so they are pretty insoluble in water.

What does increasing the mass do to volatility?

Decreases it

Are aldehydes and ketones volatile? Why?

Fairly because they don’t have hydrogen bonding and are only soluble in water when they are small

Are carboxylic acids more or less volatile than the rest? Why?

Less because they can form two hydrogen bonds per molecule which also makes they more soluble in water.

What are saturated compounds?

Only contain single bonds

What are unsaturated compounds?

Contain at least one double or triple bon

What is an addition reaction?

One where atoms are added to a molecular without any atoms being removed

Can saturated or unsaturated compounds undergo addition reactions?

Unsaturated

What type of reaction can saturated compounds undergo?

Substitution reactions, where existing atoms are switched out for new ones

What makes a carbon primary, secondary or tertiary?

A primary carbon is connected to one other carbon, a secondary carbon is connected to two other carbons, a tertiary carbon is connected to three other carbons.

What type of alcohol cannot be oxidised?

Tertiary

What does the oxidation of a secondary alcohol yield?

A ketone

What does the oxidation of a primary alcohol yield?

An aldehyde

What does the oxidation of a aldehyde yield?

A carboxylic acid

What is complete combustion?

The fuel (the alkane or alcohol) is burnt with excess oxygen to produce CO2 and H2O only. It required sufficient thermal energy to begin. During the reaction chemical energy is transferred to thermal.

What type of substitution occurs when a alkane is reacted in UV light with a halogen gas to form a haloalkane?

Photochemical Substitution

What happens if the haloalkane undergoes the same reaction again?

It forms dichloroethane and then again is trichloroethane

What happens when a haloalkane undergoes a substitution reaction?

The halogen is replaced by another atom or group of atoms

In substitution reactions, a primary haloalkane will produce a primary alcohol. True or false

True; this is the same for secondary and tertiary

What forms when ammonia is reacted with haloalkanes?

The haloalkane becomes an amine.

What do haloalkanes with cyanide produce and why can’t this reaction occur in water?

Nitriles. If done in water, the haloalkane will ignore the cyanide and produce an alcohol instead. Use ethanol instead.

Alkanes are saturated so they can undergo addition reactions. True or false

False; they cannot

What do you need to make a haloalkane from an alkene?

Halogen gases or hydrogen halide

What is Markovinikov’s rule?

If the alkene isn’t symmetrical, the hydrogen atom is more likely to bond with a carbon atom that has more hydrogens bound to it and the halogen is more likely to bond with a carbon atom with fewer hydrogens bound to it

What is required as a catalyst for the reaction of alkenes with water to produce an alcohols?

An acid such as H3PO4

Alkenes can be reacted with alkenes to produce….?

Polyalkenes

What is esterification and what type of reaction is it?

The reaction of an alcohol with a carboxylic acid to produce an ester in water. It is a condensation reaction. 

What does the reaction to form an ester need to be in the presence of?

Concentrated sulphuric acid

Why does the sulphuric acid in an esterification reaction need to be concentrated?

Because esterification is a reversible reaction and water is one of there products, therefore if a weaker acid or a dilute solution is used the reverse reaction will be favoured

What two things are combined to make amides?

Carboxylic acid and amines or ammonia

What is a way to make an amine?

Reacting nitriles with hydrogen gas in the presence of a metal catalyst

The reduction of alkenes to alkanes also involves adding H2 gas and using a …. catalyst?

Metal

An equation which adds only hydrogen to an existing molecule is a reduction reaction. True or false

True

In an elimination reaction something is removed from the molecule. True or false

True

What can be made in an elimination reaction?

Unsaturated molecules such as alkenes and alkynes

What do you use to make an alkene from a haloalkane?

A base such as alcoholic KOH

What are polymers?

A type of molecule made up of repeating monomers

Name the polymers and monomers of proteins

Polymer: Polypeptides. Monomers: Amino acids

Name the polymers and monomers of carbohydrates

Polymer: Polysaccharides. Monomers: Monosaccharides

Name the polymers and monomers of lipids

Polymer: Triglycerides, phospholipids. Monomers: Fatty acids (glycerol or phosphate head is also present)

What is the primary structure of proteins and the bonds associated with it?

The sequence of amino acids in a polypeptide chain. The bonds associated are peptide bonds

What is the secondary structure of proteins and the bonds associated with it?

The folding and coiling of the polypeptide chain. The bonds associated are hydrogen bonds which can form between amino acid residues in the chain.

What are the three categories used to describe the secondary structure of proteins?

Alpha helices, beta pleated sheets, and random coils

Alpha helices are elastic and beta sheets are inelastic. True or false

True

What is the tertiary structure of proteins and what are the bonds associated with it?

The overall 3D structure of the polypeptide chain. The bonding associated with this includes disulphide bridges (formed by covalent bonding), ionic bonds, hydrogen bonds, and dispersion forces

What is the quaternary structure of proteins?

The structured formed by the interaction of multiple polypeptide chains joined together

What are enzymes?

They are biological catalysts whose role is to enable reactions to occur at a sufficient rate (they increase collisions and thereby decrease activation energy)

What happens if the enzymes are disrupted by high temperatures or abnormal pH ranges?

The enzyme will denature and be unable to fulfil its role

Monosaccharides are simple or complex sugars?

Simple

Polysaccharides are simple or complex sugars?

Complex

Monosaccharides all follow that same empirical formula CH2O and contain hydroxyl groups, plus either an aldehyde or ketone group. For each group, what is the sugar called.

Aldehyde: Aldose, Ketone: Ketose

Molecules of alpha glucose can be joined by glycosidic bonds to form … ?

Polysaccharide starch which has two forms: amylose and amylopectin

What are the characteristic in amylose and amylopectin?

Amylose: Glucose monomers are joined by 1-4 glycosidic linkages into a chain without branching which coils into a helix. Amylopectin: Chain contains branching due to some glucose units forming a 1-6 glycosidic linkage

Cellulose is a polysaccharide made up of beta-glucose monomers joined by glycosidic bonds. It doesn’t contain branching, forming straight chains rather than coils. This differences due to the different location of a hydroxyl group in the beta-glucose. The chains are layered with what type of bonding to form a strong a rigid structure?

Hydrogen bonding

What are triglycerides?

A form of lipid which contains a glycerol unit joined by ester functional groups to three fatty acids. The properties depend on the fatty acids whether they are unsaturated or saturated.

Saturated fatty acids can pack together more tightly than unsaturated and therefore tend to experience stronger dispersion forces and have higher melting points than unsaturated. True or false

True

What is saponification and what type of reaction is it?

A strong base is used to break the ester bonds between glycerol and the fatty acids resulting in three free fatty acid salts and one glycerol. It is a hydrolysis reaction meaning water is involved in breaking down the polymers into monomers

Fatty acid salts are soaps, with the properties of the soap influenced by the fatty acid chain and the cation introduced by saponification. How do soaps work?

The polar end of the fatty acid salt (with the cation and C double bond O) is highly soluble in water while the fatty acid chain is highly soluble in organic solvents. This results in the formation of microscopic balls known as miscelles which remove oily grease

What does hard water cause the formation of unwanted products?

It contains metal ions which can form scum. It is unwanted, insoluble precipitate formed when these metal ions are substituted into fatty acid salts

What is polyethene?

It is made up of many ethene monomer joined together in addition polymerisation with the presence of a catalyst.

The monomer (ethene) is unsaturated and the polymer (polyethene) is saturated. True or false

True

Lower density polyethene has more branching than high density polyethene. What does this cause?

Weaker dispersion forces therefore is weaker and more flexible and has a lower boiling point

What is polypropene?

It is made from propene monomers joined together in addition polymerisation with the presence of a catalyst.

What are the three groups polypropene can be categorised into based on the orientation of its methyl groups and what do they mean?

Isotactic: all the groups are on the same side, Syntactic: the groups alternate which side they are on, Atactic: the groups are random

Isotactic polypropene has the highest density, melting temperature and greatest rigidity and atactic has the lowest. True or false

True

What is polytetrafluoroethene?

It is made from many tetrafluoroethene monomers joined together in addition polymerisation. The carbon-fluorine bonds are incredibly strong are it is chemically inert. These bonds also result in polytetrafluoroethane being flexible, having a very high melting point, being resistant to dispersion forces, and being electrically resistant