chem lab gyatt

Carbonyl group (C=O)

Aldehydes and ketones contain what functional group?

polar nature, soluble

Aldehydes and Ketones have ______ due to increased electron density at the oxygen atom, making them _____ in water

oxidation, reduction, addition, substitution

Carbonyl groups may undergo what 4 reactions?

Carboxylic Acids

Aldehydes can undergo oxidation to form

Chromic acid and Permanganates

What are the typical oxidizing agents for aldehydes?

Ammoniacal silver nitrate

Specific test for the presence of aldehydes uses ________ to form carboxylic acid and the reduced silver metal

primary alcohols

Aldehydes treated with reducing agents forms _______

secondary alcohols

Ketones do not undergo oxidation, however they can become______ when reduced

Dinitrophenylhydrazine

Meaning of DNPH?

carbon and hydrogen

Organic compounds are primarily composed of __ and __ atoms along with heteroatoms

ester

When alcohols and carboxylic acids react, they form an ____.

volatile substances, lower BPs

Esters are _____ that have ______ than alcohol and carboxylic acids

naturally or can be synthesized in the lab

Esters can occur how?

Fischer Esterification

Synthesis of esters from alcohol and carboxylic acids in the presence of an acid catalyst

Chromatography

“Color Writing.” Method of separating the components of a mixture. Widely used for qualitative and quantitative analyses

stationary and mobile phase

Mixture is partitioned between what 2 phases?

Mobile Phase

May be liquid or gas, nonpolar. Carries the components of the mixture through the medium being used

Stationary Phase

Remains fixed in place. May be solid or liquid film coated on a solid surface, polar. Acts as a constraint on many of the components in a mixture, slowing them down to move more slowly than the mobile phase

Greater affinity for the mobile phase

Individual components become separated into zones or bands

Greater affinity for the stationary phase

Compounds stays even with a passing mobile phase

mobile phase flows over stationary phase

Components in a mixture are continuously equilibrated between the two phases according to their distribution coefficients as __________

○ Thin-layer chromatography (TLC)

○ Liquid chromatography (LC)

○ High-performance liquid chromatography (HPLC)

○ Gas chromatography (GC)

The different types of chromatography

column chromatography

In this experiment, capsaicin was extracted from chili peppers using ______, which involves a stationary solid phase that absorbs and separates compounds as they pass through with the help of a liquid mobile phase

Silica gel

is the most widely used stationary phase

Thin-layer chromatography

Became a widely used analytical technique. Is another separation technique to confirm that capsaicin has been successfully extracted from the chili peppers. Simple, inexpensive, fast, and efficient

pure solvent, a mixture of solvents

Mobile phase can be a _____ or ______

Developing the chromatogram

A process wherein the solvent rises through the stationary phase by capillary action

Retardation factor (Rf)

Dimensionless quantity that reflects the affinity of the compound for the stationary or mobile phase

Rf values

can be used in the qualitative identification of compounds

Capsaicin

Fiery chemical compound in chili peppers that causes their spicy heat by activating pain/heat receptors in our bodies

Phytochemicals

a.k.a. Secondary metabolites. Plant compounds not essential for basic growth but vital for defense, attraction, and signaling, giving plants colors, smells, and flavors

Extraction

“Pulling out” of a substance from one phase by another phase. Term is usually used to describe the removal of a desired compound from a solid or liquid mixture using a solvent

Filtration

Process in which solid particles in a liquid or gaseous fluid are removed by the use of a filter medium that permits the fluid to pass through but retain the solid particles

gravity filtration and suction filtration

two types of filtration

Decantation

Simplest way of separating a liquid or solution from a solid. Solids settle at the bottom and by gently and slowly pouring the liquid portion into another container without disturbing the solids. Not used when the solid is floating or suspended in the liquid

Chromatogram

Result of chromatography

Chromatograph

Instrument used to conduct chromatography

Liquid chromatography (LC) and Column chromatography

Generally used in separating compounds of low volatility

High-performance liquid chromatography (HPLC)

Separates, identifies, and quantifies components in a liquid mixture by passing it under high pressure

Gas chromatography (GC)

Analytical separating techniques used to analyze volatile substances in the gas phase

Elution

A process of extracting one material from another by washing it with a solvent

Isocratic

Composition of eluent remains constant throughout the entire separation process. Used in the experiment

Gradient

Involves a gradual, intentional change in the mobile phase’s composition over time to improve the separation of solutes

Toluene

Solvent used in the extraction of capsaicin (orange upper layer)

UV Lamp

The separated compounds usually appear as dark spots

Iodine visualization

Using the adsorption of iodine (I2) vapor. Uses a bottle containing a thin layer of iodine crystals

Organic chemistry

Branch of chemistry that deals with compounds that are largely made of carbon and hydrogen. Oxygen, nitrogen, sulfur, phosphorus, and halogens are also found

Carbon

has a unique ability to form long chains with other carbons, forming large and complex molecules

Solubility

Amount of solute that dissolves in a given amount of solvent

○ Water

○ Ether

○ 5% HCl (Hydrochloric acid)

○ 5% NaOH (Sodium hydroxide)

○ 5% NaHCO3 (Sodium bicarbonate)

○ Concentrated sulfuric acid (H2SO4)

Most common solvents used in solubility testing for the experiment:

solute-solvent relationship and intermolecular forces

Results depend on the _______ and _______ between interacting species — “like dissolves like”

ionic compounds

Most_____ are soluble in water

Branched chains

_____ are more soluble than straight chains

functional group

Organic compounds are classified based on the type of _____ that they possess

○ Substitution

○ Addition

○ Elimination

○ Rearrangement

Organic reactions may undergo

Hydrocarbons

Compounds that contain exclusively carbon and hydrogen. Can be classified

Alkanes, alkenes, and alkynes

are aliphatic acyclic hydrocarbons

Cycloalkanes and cycloalkenes

are aliphatic cyclic hydrocarbons

big enough, 180º

Cycloalkynes may exist if the ring is _____ to reduce the strain required to maintain approximately ___ geometry

Aromatic hydrocarbons

are generally cyclic with alternating double and single bonds

substitution

Alkanes and aromatic hydrocarbons typically undergo, though not limited to, _____ reactions

addition, oxidation, and reduction

Alkenes and alkynes usually undergo _____, ______, and ______ reactions

Alkyl halides/Haloalkanes, substitution and elimination reactions, alcohol and alkenes

Hydrocarbon + Halogen (F, Cl, Br, I), Very reactive and undergo ______ and _______ to form ______ and _______

Bromine water

Toxic and corrosive, harmful if inhaled. Causes respiratory tract irritation and possible burns. May cause digestive tract irritation with nausea, vomiting, and diarrhea

Bromine water (Br(aq)) and Baeyer’s reagent (Potassium permanganate; KMnO4)

Tests for unsaturated hydrocarbons (alkenes and alkynes)

Ethanolic silver nitrate (C2H6AgNO4)

Tests for secondary and tertiary alkyl halides

Concentrated sulfuric acid (H2SO4)

Tests for alkenes and tertiary halides