History of Chemistry
This 19th-century scientist proposed that atoms combine in whole-number ratios, laying the foundation for modern atomic theory.
Who is John Dalton?
This intermediate forms during an SN1 reaction after the leaving group departs.
What is a carbocation?
This reactive species forms when a base removes an α-hydrogen from a carbonyl compound.
What is an enolate?
The peptide bond is formed when the amino group of one amino acid reacts with this functional group of another.
What is a carboxylic acid (or carboxyl group)?
The longest carbon chain containing the functional group determines this fundamental part of an IUPAC name.
What is the parent chain?
This chemist’s periodic system arranged elements by increasing atomic weight and predicted the existence of undiscovered elements.
Who is Dmitri Mendeleev?
In an E2 elimination, the β-hydrogen removed by base must be positioned this way relative to the leaving group.
What is anti-periplanar?
Mixing an aldehyde with no α-hydrogens and another with α-hydrogens can lead to this condensation reaction.
What is a crossed aldol reaction?
Carbohydrates often form rings through nucleophilic attack of this group on the anomeric carbon.
What is a hydroxyl group?
A benzene ring with a methyl substituent is known by this common name, but IUPAC names it as methylbenzene.
What is toluene?
The gold-foil experiment, performed in 1909, led to the discovery of this atomic structure.
What is the atomic nucleus?
The reaction in which a hydride shifts to form a more stable cationic intermediate is known as this.
What is a carbocation rearrangement?
A nitrile can be hydrolyzed under acidic or basic conditions to produce this type of carbonyl compound.
What is a carboxylic acid?
Fatty acids are activated by reaction with CoA to form this thioester before entering β-oxidation.
What is acyl-CoA?
The substituent name for a cyclic structure attached to a parent chain, such as C₆H₁₁–, is written this way.
What is cyclohexyl?
This scientist’s oil-drop experiment was the first to accurately measure the charge of the electron.
Who is Robert Millikan?
This aromatic substitution mechanism proceeds through a σ-complex intermediate before restoring aromaticity.
What is electrophilic aromatic substitution?
This reaction converts an aldehyde or ketone into an alkene using phosphorus ylide chemistry.
What is the Wittig reaction?
The Maillard reaction between amino acids and reducing sugars forms these complex flavor-generating polymers.
What are melanoidins?
This prefix indicates that two identical substituents are attached to the same carbon atom in a molecule.
What is geminal (or gem-)?
This physicist’s 1924 proposal introduced the dual wave-particle nature of matter, influencing quantum mechanics.
Who is Louis de Broglie?
This name describes the mechanism where a nucleophile attacks a carbonyl carbon followed by proton transfers, forming a tetrahedral intermediate.
What is nucleophilic acyl substitution?
β-Keto esters or 1,3-dicarbonyl compounds undergo this decarboxylation-driven reaction to form cyclic products.
What is the Dieckmann condensation?
This coenzyme participates in biological redox reactions by accepting a hydride to form its reduced form, NADH.
What is NAD⁺?
The IUPAC name 2-bromo-4-ethyl-3-methylpentane reflects this rule that determines the numbering of substituents.
What is the lowest-locant rule?