Chem unit 4 AOS 1 ~ Organic

Primary, secondary, tertiary alcohols, aldehydes, ketones and esterfication definitions and processes

PA- has a hydroxyl group on terminal carbon

SA- the hydroxyl group attached to carbon with two alkyl sides

TA- The hydroxyl group attached to carbon with three alkyl side groups

A- Has CHO group on terminal carbon

K- has a ketone - C double bond O group on non-terminal

E- contains an ester group of -COOC-

Carboxylic acid, structural formula, semi structural formula, skeletal structure and molecular and empirical formula

Carboxylic acid: organic compound with -COOH group.

Structural formula: shows arrangement of atoms.

Semi-structural formula: abbreviated representation with bonds.

Skeletal structure: simplified form focusing on carbon backbone.

Molecular formula: shows total atoms; empirical formula: simplest ratio of elements.

Empirical formula : shows the simplest whole-number ratio of elements in a compound.

Organic chem

Organic chem is the study of carbon containing compounds. Most sources come from crude oil, can be used to make everything from diesel, waxes and fuel. Number of valence elections in 4, covalent bonds, strong strength of bonds and bonds with H, C, F, O, CL, N, Br, I.

Hydrocarbons and the three groups

Hydeocarbon refers to molecules which are made only from carbon and hydrogen atoms sourced from crude oil ( mixture of hydrocarbons that are formed undergournd from reviews of animals and plants ).

Three groups include Alkanes, saturated with formula CnH2n+2 , Alkenes, Unsaturated with formula CnH2n and Alkynes, Unsaturated with formula CnH2n-2

Alkanes

Formula CnH2n+2, contains single carbon-carbon bonds ( saturated ). In homologous series, each family differs from the previous member by a Ch2 group, as it gets longer, melting and boiling point increase, density and viscosity increase. Non- polar, strength is dispersion forces, flameability decreases as molecule increases

Alkenes

Formula is CnH2n, double carbon - carbon bonds ( unsaturated ), each member differs from previous one by Ch2 so series is homologous. Double bond means more reactive due to double bond being broken and other atoms added. Melting and boiling point, density and viscosity increase with molecule increae. Non-polar, bonding is dispersion forces, flamability decreases as molecule increase for large alkene molecules, there are structural isomers that are possible.

Alkynes and IUPAC rules

Alkynes are hydrocarbons with the formula CnH2n-2, containing triple carbon-carbon bonds (unsaturated). The IUPAC rules for naming alkynes include identifying the longest carbon chain containing the triple bond and numbering the chain to give the lowest possible numbers to the triple bond.

Alcohols and properties

Alcohols contain a hydroxyl functional group ( -O-H).

Properties: Small alcohol molecules are useful as fuels as they undergo combustion reactions e.g. Ethanol - C2H5OH + 3Ox goes to 2CO2 + 3H2O. Boiling point increases as molecule does as longer carbon chains means more dispersion forces means more energy required to disrupt dispersion forces to seperate molecules meaning higher boiling point.

Esters

Esters are formed when a carboxylic acid reacts with an alcohol in an esterfication reaction. Water is formed so this is a type of condensation reaction ( -oate ending)

Amines, Amides, Aldehydes and ketones

Amines - R-NH2 ( Amino)

Amides - R-CONH2 ( Carboxyl + amide = Amide)

Aldehydes - Alkanals with a carbonyl group -RCOH- at the end of chain of carbons.

Ketones - Alkanones - RCOR - never at end of carbon chain with carbonyl group

First 6 alkanes names and molecular formula for each

The first six alkanes are: Methane (C1H4), Ethane (C2H6), Propane (C3H8), Butane (C4H10), Pentane (C5H12), and Hexane (C6H14). These are saturated hydrocarbons characterized by single bonds between carbon atoms.

When naming a hydrocarbon, list the following terms of which comes first to last. Functional groups/number of double bonds, Substituents and Main hydrocarbon chain

Substituents, main hydrocarbon chain and then functional group/double bonds

Fill in table of 6 hydrocarbons with formal and suffix next to them

1. Alcohol: -OH (suffix: -ol)

1. Ketone: -CO (suffix: -one)

2. Aldehyde: -COH (suffix: -al)

3. Carboxylic acid: -COOH- (suffix: -oic acid)

4. Amine: -NH2 (suffix: amine)

5. Amide: -CONH2 (suffix: -amide)

Difference between geometric and structural isomerism

Geometric isomerism involves different spatial arrangements of groups around a double bond or ring structure, while structural isomerism refers to different connections of atoms within the molecule, leading to different chemical structures.

What 2 reactions are required to convert fatty acids into biodiesel

Condensation reaction/esterfication - 3 fatty acids + glycerol forms triglyceride

Transesterfication - triglyceride + KOH + methanol forms biodiesel + glycerin

Would a straight-chain or branched-chain hydrocarbon have a higher boiling point and why?

A straight-chain hydrocarbon would generally have a higher boiling point than a branched-chain hydrocarbon due to stronger intermolecular forces and a larger surface area, allowing for more effective van der Waals interactions. It has stronger dispersion forces due to proximity of hydrogens.

What is the equation for the phtochemical reaction of methane with chlorine gas?

Ch4 + CL2 - CH3CL + HCL The photochemical reaction of methane with chlorine gas involves the substitution of hydrogen atoms by chlorine atoms, forming chloromethane and hydrochloric acid.

What product would you get if you reacted a haloalkane with a hydroxide ion

Alkanol - CHHHCL with arrow with OH- to CHHHOH Alkanol (alcohol). This reaction involves nucleophilic substitution where the hydroxide ion replaces the halogen.

What would an alkene react with to form the following products - Haloalkane, Alkanol and Alkane

H - HCL, CL2, Br2 or I2

Alkanol - H20 (water) + weak acid

Alkane - H2 + Pt

what product is produced from the oxidation of a secondary alkanol

ketone, such as acetone or 2-butanone. This reaction typically involves the removal of hydrogen and the addition of oxygen. CH3CH3CHOH - arrow with Cr2O7 2- at top and H+ at bottom forming CH3CH3C double bond O. The product is a ketone, formed when secondary alkanols are oxidized, typically represented by the reaction with dichromate under acidic conditions.

Complete the reaction pathway from oxidation of a primary alkanol

Alkanol - arrow with Cr2O7 2- at top and H+ at bottom - Aldehyde with the same arrow and then formed carboxylic acid. The oxidation of a primary alkanol first produces an aldehyde, which can further oxidize to form a carboxylic acid. The overall reaction involves the removal of two hydrogen atoms and the addition of an oxygen atom.

Physical properties of Alkanes and Alcohols

A- Alkanes only have dispersion forces, which increase with carbon chain length (intermolecular bonds). The first 4 alkanes are colorless, oderless gases at room temperature. Alkanes with 5 or more carbons are liquids at RT and become more viscous before becoming semisolids. Small A are highly flammable as CC increases (Non-polar and unreactive compared to alkenes and they use substitution)

Al- Alcohols are colorless, the ones with smaller carbon chains are polar and are miscible in water. They exhibit hydrogen bonding with themselves and water, alcohols have higher boiling point than some size alkanes due to their hydrogen bonds.

Physical properties of Alkenes and esters

A- Alkenes only have dispersion forces which increase with the carbon chain length. Alkenes with 4 or more carbons are liquids, very long carbon chains are solids. Ethene is most important because its stating point for the synthesis of many compounds. Ethene is non-polar and insoluble in water, colorless, flammable and unsaturated due to double bond ( use addition ).

E- esters with short CC are liquids but longer esters become more oily and eventually solids. Esters have a pleasant odour and are used in flavourings, they are polar molecules and have dipole dipole interations. Small esters are soluble as they form hydrogen bonds and react with water to cause hydrolysis.

Physical properties of haloalkanes

H- Have a dipole dipole bonding, the two highest chloralkanes are gases, as it first Bromoalkene. All H are liquids at RT except very long chains which are solids. As the carbon chain gets longer, dispersion forces become dominant intermolecular forces. Gas liquid haloalkanes have sweet odour, because chloranes high electrogrativity leads to polar bonds. Haloalkanes are generally insoluble in water.

Physical properties of carboxylic acids

Carboxylic acids are polar molecules that exhibit strong hydrogen bonding, leading to higher boiling points compared to similar-sized alkanes and alcohols. They are typically liquid at room temperature, have distinctive sour odors, and are soluble in water due to their ability to form hydrogen bonds with water molecules. Fatty acids are not soluble as dispersion forces dominate with length of CC. CA act as weak acids, becoming proton donors as highly electrogrativc O atoms in C double bond O group, pulls electrons away amoung O-H group weakening it.

Physical properties of Aldehydes and ketones

Al - are polar molecules that exhibit dipole-dipole interactions. They have moderate boiling points relative to hydrocarbons, are typically liquid at room temperature, and have distinctive odors. Aldehydes are generally more reactive than ketones due to the presence of the carbonyl group at the end of the carbon chain, easily oxidised

K- Ketones with smaller chains are liquids and longer chains are solids. Soluble in water due to hydrogen bonding but cannot form hydrogen bonding themselves, they are resistant to oxidation, ketones with smaller CC are useful solvents

Physical properties of primary amines and primary amides

PAMINES - first two PA are gases, becoming liquids and then solids as CC increases, primary amines have a fishy odour, smaller primary amines for hydrogen bonds with each other and water, therefore very soluble. PA are weakly basic and react with acids to form ammonium salts.

PAMIDES- Methanamide is a solid, while larger amides are typically liquids. They have stronger intermolecular hydrogen bonding than primary amines, leading to even higher boiling points. Primary amides are polar and soluble in water due to their ability to form hydrogen bonds. They generally have a faint odor.

Combustion reactions

Balancing equations = C then H then O.

General equation is : Hydrocarbon (fuel) (g) + O2 (g) to CO2 (g) + H2O (g)

e.g combusion of pentanoic acid is: C5H10O2 (l) + 7.5 O2 (g) arrow 5 CO2 (g) + 5 H2O (g). This reaction releases energy and results in complete oxidation. Can also form incomplete combustion with CO instead of CO2 for product.

Substitution reactions

Occurs when an atom or group replaces another atom/group resulting in new substance formation. Only saturated hydrocarbons (alkanes) can undergo substitution reactions.

Some requations require UV or heat as a catalyst to indicate reaction by breaking bonds between diatonic halogen.

e.g. Substitution of Alkane + Halogens, Primary Halogens and Alkali, water, amonia, and also primary alcohols with ammonia.

Addition reactions

The carbon-carbon double bonds in alkenes are broken to allow the molecule to add other atoms or groups (results in formation of single product). Only unsaturated molecules (alkenes) can undergo addition. AR between alkenes and hydrogen - alkenes can undergo addition reactions with hydrogen to form alkanes (hydrogenation), requiring metal catalyst like nickel or platnium. Alkenes and hydrogen halide produces haloalkane. Alkenes and halogens produce (di)Haloalkaane called halogenation. Alkene and water vapor produce alcohol ( requires concentrated H3PO4 as catalyst and also heat and pressure). Called hydration. Alkene monomers are long polymers (polymerisation) requires a catalyst, heat and pressure

Oxidation reactions

The oxidation of alcohols is an important organic reaction as it allows ketones, aldehydes and carboxylic acids to produce. These reactions require oxidants (mnO4 - and Cr2O7 2-) whihc have been acidified in H+.

Oxidation of primary alcohol to aldehyde and carboxylic acid, steps to maximise production of aldehyde instead of allowing CA to form. Limit the head of reaction ( temp), limit the oxidising agent avaliable in reaction and remove the aldehyde as it is being produced by distillation. Oxidation of secondary alcohol to ketone ( when secondary alcohol is oxidised, creates ketone due to locations)

Condensation reactions

Condensation reactions are a type of organic reaction where two molecules combine to form a larger molecule, accompanied by the loss of a small molecule, often water. These reactions are commonly seen in the formation of esters from alcohols and carboxylic acids or in the synthesis of polymers.

Hydrolysis reactions ( Hydrolysis of esters)

Condensation reactions are reversible. When water is added to ester, it breaks the bonds in the ester link between carbon and oxygen to reform original reactants. Concentrated sulfuric acid (H2SO4) required as catalyst. e.g. Propyl ethanoate + H2O to Propyl + ethanoic acid

Transesterfication reactions

A triglyceride is made of 3 fatty acids / long carboxylic acids which are bonded to glycerol molecule ( IUPAC name- Propane-1,2,3-triol).

When a triglyceride is reacted with 3 methanol molecules, the original backbone is is broken, a methyl group is added onto the single-bonded oxygens and glycerol is formed as by-product.

This transfers ester bond and seperates the fatty acid chains, turning them into methyl esters (transesterfication). A strong alkali (OH-) requires as a catalyst. These fatty acid methyl esters make up biodiesels and can be used as a more suitable alternative to diesel obtained from fossil fuels.

Esterifcation

An esterfication reaction is a particular type of condensation reaction where a carboxylic acid and an alcohol react to produce water molecule and easter. Concentrated sulfuric acid (H2SO4) is required as a catalyst to remove hydroxyl group (OH) from CA, along with hydrogen atom from hydroxyl group of an alcohol to form H2O.

Esterfication between alcohol and carboxylic acid, condensation reactions between carboxylic acid and ammonia e.g. ethanoic acid + NH3 goes to ethanamide + water (forms water and primary amide). COndensation of diotic acids and dids or diamines (requires catalyst, head and pressure). Dioic (carboxyl groups at both ends). Dids ( Hydroxyl groups at both ends) Diamines (amino group at both ends).

Condensation and hyoclrolytic reactions of Biomolecules

When biomolecules are being synthesised, water is always a product ( Condensation), whereas when biomolecules are being broken down, water is a reactant (Hydrolysis).

Glucose can be stored as glycogen and then oxidised in cells to release energy. Proteins from food are broken down in body (hydrolysis) and also synthesised (condensation) in body. Triglycerides can be stored in adipose tissue, then oxidised in muscles to release energy

proteins

Porteins are long chain polymers, made up of many amino acids linked by peptide bonds. They play essential roles in biological processes, including catalysing reactions, transporting molecules, and providing structural support. There are 20 common 2-amino acids. It has one amino group, one carbonyl, one side chain, and one bonded to central carbon. Amino + carboxyl separated by enteral carbon, only diffent in structure for 2-amino is R chain condensation reactions to synthesis proteins, proteins also called polypeptide are products of condensation reactions between 2-amino acids

Hydrolysis reactions to break down proteins in detail

Hydrolysis reactions involve the addition of water to proteins, leading to the cleavage of peptide bonds and resulting in the release of individual amino acids. This process is essential for digestion, as it allows proteins consumed in the diet to be broken down into absorbable units for cellular use.

Carbohydrates

Carbohydrates are organic compounds composed of carbon, hydrogen, and oxygen, typically with a ratio of 1:2:1. They serve as a primary energy source in living organisms and are classified into monosaccharides, disaccharides, and polysaccharides, which play crucial roles in metabolism and structural functions.

Hydrolysis reactions to break down carbohydrates

Hydrolysis reactions to break down carbohydrates involve the addition of water, leading to the cleavage of glycosidic bonds, resulting in the release of individual monosaccharides. This process is crucial for the digestion of complex carbohydrates into simpler sugars that can be readily absorbed by the body.

Condensation reactions to synthesis lipids ( fats and oils )

Fat and oils are two common types of triglycamides (lipids) with different physical and chemical properties.

Lipids are commonly found in meat and fish. similar to carbohydtaes, lipids provide energy to body, however lipids contain more than double energy per gram. Triglycerids are fats(solid) or oils (liquid) when 3 long chain fatting acids react with glycerol it helps create the backbone of the triglyceride linking 3 fatty acids to form a lipid molecule through the removal of water, known as dehydration synthesis. This reaction forms ester bonds between the fatty acids and glycerol, resulting in the creation of triglycerides, which serve as an important energy reserve in the body.

Hydrolysis reactions to break down lipids

Hydrolysis reactions to break down lipids involve the addition of water, leading to the cleavage of ester bonds, which results in the release of fatty acids and glycerol. This process is essential for the digestion of triglycerides into their constituent components for absorption and utilization by the body.

Efficiency of reactions

Not all of the reactants in chemical reaction are consumed and result in complete creation of products. Similarly, not all of products made are the desired amount of products e.g. when making esters, water is made as a by product, so what percentage of the reactants actually go into producing the ester.

All reactions have different levels of efficiency. It is important to consider the efficiency of reactions when deciding which pathway to utilise for chemical product.

Atom economy

Atom economy refers to a measure of the efficiency of a chemical reaction in converting reactants into desired products. It is calculated by comparing the mass of the desired product to the total mass of all reactants used, and higher atom economy indicates less waste and more sustainable processes.

percentage yield and how calculated

Percentage yield is a measure of the efficiency of a chemical reaction, calculated by dividing the actual yield of the product by the theoretical yield and multiplying by 100. It reflects how much of the expected product is actually produced in a reaction.

Boiling point, distillate, fractional distillate, melting point and mixture definitions

BP- the temperature at which a liquid's vapor pressure equals the external pressure, allowing it to transition to the gas phase.

D- The liquid collected during distillation after evaporation and subsequent condensation.

FD- A distillation process that separates components based on different boiling points, allowing for the separation of multiple liquid mixtures.

MP- The temperature at which a solid becomes a liquid, indicating a phase change.

M- A combination of two or more substances that retain their individual properties and can be separated by physical means.

Pure substance, simple distillation, vapour pressure and volatile

A pure substance is a material that has a constant composition and consistent properties throughout.

Simple distillation is a technique used to separate components in a liquid mixture based on boiling point differences.

Vapour pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase.

A volatile substance is one that readily evaporates at normal temperatures.

Determining purity from melting point in detail

Determining purity from melting point involves measuring the melting point of a substance and comparing it to the known melting point of the pure substance. A lower melting point or a wider melting range indicates impurities, while a sharp melting point close to the expected value suggests high purity.

Simple + fractional distillation

Simple distillation is a process of separating liquids based on boiling point differences through a single evaporation-condensation cycle, while fractional distillation involves multiple cycles to separate components in a mixture more effectively, allowing for precise isolation of liquids with closer boiling points. Distillation is a process used to separate components in a liquid mixture, capitalizing on differing boiling points to achieve separation.

Qualitative tests and pressure of carbon carbon double bonds

Qualitative tests for carbon-carbon double bonds involve chemical reactions that indicate the presence of unsaturation, such as the addition of bromine or potassium permanganate, which leads to characteristic color changes. The pressure of the carbon-carbon double bond refers to the stability and reactivity associated with the π-bond, influencing the compound's physical and chemical properties.

Potassium pernanganate test

A qualitative test used to detect the presence of unsaturated compounds, particularly carbon-carbon double bonds. When potassium permanganate is added to such compounds, it undergoes a redox reaction, resulting in a color change from purple to brown, indicating unsaturation.

What to rinse burette, flasks and equiptment used

Rinse burettes, flasks, and equipment with the solution they will contain to remove any impurities and ensure accurate measurements. This prevents contamination that could affect experimental results.

Measurement of a degree of unsaturation

A method to quantify the level of unsaturation in organic compounds, typically calculated by determining the number of carbon-carbon double bonds and rings present in a molecule, which can influence its reactivity and stability.

Presence of hydroxyl function group + acidified potassium dichanale test

This test detects the presence of hydroxyl functional groups in organic compounds using acidified potassium dichromate, which undergoes reduction, changing color from orange to green, indicating the alcohol's presence.

Acidified potassium dichanale followed by the silver mirror test and lucas test

A series of tests used to identify different types of alcohols. Acidified potassium dichromate detects alcohols by changing color from orange to green, the silver mirror test identifies aldehydes by producing a reflective silver coating, and the Lucas test differentiates primary, secondary, and tertiary alcohols based on the rate of reaction with hydrochloric acid.

Presence of carboxyl function group and acid-base indicator test

POCFG- A method to identify carboxyl functional groups in organic compounds using an acid-base indicator, which changes color in response to pH changes, confirming the presence of a carboxylic acid.

ABIT - A method using acid-base indicators to confirm the presence of carboxylic acids by observing pH-induced color changes.

esterfication test and reaction with metal carbonates or metal bicarbonates

A method used to identify the presence of carboxylic acids and their reactivity. The esterification test involves reacting acids with alcohols to form esters, while the reaction with metal carbonates or bicarbonates produces carbon dioxide gas, confirming the presence of an acid.

Equivilance and end points (aliquot, concentration, concordant titres, indicator, iodine value and meniscus

Equivalence and end points refer to the stages in a titration where the amount of titrant added is stoichiometrically equivalent to the substance being titrated. Key concepts include aliquots as measured volumes of titrant, concentration as the amount of substance in a given volume, concordant titres representing consistent volume measurements, indicators that signify end points through color change, iodine value indicating unsaturation in fats, and meniscus which is the curve at the surface of a liquid in a container.

Standardised solution, titre, titration and volumetric analysis

A standardized solution is a solution of known concentration used in titration to determine the concentration of another solution. The titre is the volume of titrant added to reach the equivalence point during a titration, while titration is a quantitative analytical method to determine the concentration of a solution. Volumetric analysis involves measuring the volume of a solution to calculate concentrations and is fundamental in these procedures.

Basic titration principles

Basic titration principles involve the systematic method of adding a titrant to a solution until the reaction reaches its equivalence point. This process allows for the determination of the unknown concentration of the analyte, using indicators to signal the completion of the reaction.

Linoleic and stearic acids as well as palmitic acids. explain what they are and difference in melting points

Linoleic, stearic, and palmitic acids are fatty acids with distinct characteristics. Linoleic acid is a polyunsaturated omega-6 fatty acid, while stearic and palmitic acids are saturated fatty acids. The main difference lies in their melting points: stearic acid has a higher melting point due to its longer carbon chain and saturation, while linoleic acid remains liquid at room temperature because of its double bonds.