UMD CHEM134 Final Vocabulary

vol%

volume percent

Addition Polymerization

a type of polymerization in which the monomers simply add together to form the polymer, with no other products

Resonance

a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by one single Lewis structure

Thermochemical Equation

an equation that includes the quantity of energy released or absorbed as heat during the reaction as written

Spectator Ion

an ion that appears on both sides of an equation and is not directly involved in the reaction

Aldehydes

an organic compound containing a functional group with the structure −CHO, consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain.

Esters

an organic compound made by replacing the hydrogen of an acid by an alkyl or other organic group. Many naturally occurring fats and essential oils are esters of fatty acids.

Carboxylic Acid

an organic compound that contains a carboxyl group (C(=O)OH). The general formula of a carboxylic acid is R-COOH, with R referring to the rest of the (possibly quite large) molecule.

Acyl Chlorides

an organic compound with the functional group -COCl. Their formula is usually written RCOCl, where R is a side chain.

Ketones

an organic compound with the structure RC(=O)R', where R and R' can be a variety of carbon-containing substituents. Ketones and aldehydes are simple compounds that contain a carbonyl group (a carbon-oxygen double bond).

Organic Compound

any chemical compound that contains carbon

Chelate

any coordination compound composed of a central metal atom and an organic molecule composed of multiple bonds in a ring structure

Alcohols

any of a class of organic compounds characterized by one or more hydroxyl (―OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain)

Alkanes

any of the series of saturated hydrocarbons including methane, ethane, propane, and higher members.

Alkenes

any of the series of unsaturated hydrocarbons containing a double bond, including ethylene and propylene.

Alkynes

any of the series of unsaturated hydrocarbons containing a triple bond, including acetylene.

Ethers

any organic compound with a structure similar to ether, having an oxygen atom linking two alkyl or other organic groups. R-O-R

Polydentate

attached to the central atom in a coordination complex by two or more bonds.

Amines

formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group

Coordinate Covalent Bond

forms when one atom donates a pair of electrons to be shared with an atom or ion that needs two electrons to become stable

Electron Density

gives the probability that an electron will be found in a particular region of an atom

Alkyls

group of atoms that would be obtained by removing a hydrogen from an alkane

Hybrid Orbital

orbitals of equal energy produced by the combination of two or more orbitals on the same atom

Aromatic Compounds

organic compounds containing a benzene ring

Organic Halides

organic compounds containing a halogen atom bonded to a carbon (C) atom

PPB

parts per billion

PPM

parts per million

Percent Weight

percent of weight of solution in the total volume of solution

Matter

physical substance in general, as distinct from mind and spirit; (in physics) that which occupies space and possesses rest mass, especially as distinct from energy.

Energy

power derived from the utilization of physical or chemical resources, especially to provide light and heat or to work machines.

Titration

process in which a solution of known concentration is used to determine the concentration of another solution

Bronsted-Lowry base

proton acceptor

Bronsted-Lowry acid

proton donor

Phenyls

six carbons, five hydrogens in essentially benzene ring, aromatic compounds

Law of Definite Proportions

states that, regardless of the amount, a compound is always composed of the same elements in the same proportion by mass

Potential Energy

stored energy that results from the position or shape of an object

Thermodynamics

study of the flow and transformation of energy in the universe

Nonelectrolytes

substances that form no ions in water and cannot conduct electricity

Electrolytes

substances that release ions in water

Mole

the SI unit of amount of substance

Percent Error

the absolute value of the error divided by the accepted value, multiplied by 100%

Observation

the action or process of observing something or someone carefully or in order to gain information.

Endothermic

(of a chemical reaction or compound) occurring or formed with absorption of heat

Saturated Hydrocarbons

A hydrocarbon in which all the bonds between carbon atoms are single bonds

Unsaturated Hydrocarbons

A hydrocarbon in which one or more of the bonds between carbon atoms is double or triple

Electronegativity

A measure of the ability of an atom in a chemical compound to attract electrons

Concentration

A measurement of how much solute exists within a certain volume of solvent

Racemic Mixture

A mixture that contains equal amounts of the (+) and (-) entantiomers. Racemic mixtures are not optically active.

Anion

A negatively charged ion

Cation

A positively charged ion

Scientific Law

A statement that describes what scientists expect to happen every time under a particular set of conditions

Phenols

-aromatic alcohols -Hydroxyl groups can be attached to aromatic rings (these hydroxyl hydrogens are very acidic due to possible resonance b/w the ring & the lone pairs on the O atom) -Two groups on adjacent carbons are called ortho- or o- -Two groups separated by a carbon is called meta- or m- -Two groups on opposite sides of the ring are called para- or p-

Standard State Pressure

1 atm

Compounds

2 or more elements chemically combined

Standard State Temperature

25 degrees Celsius

Covalent Bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Molecular Formula

A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms.

Chemical Formula

A combination of chemical symbols and numbers to represent a substance

Ionic Compound

A compound that consists of positive and negative ions

Inorganic Compound

A compound that does not contain carbon

Polar Covalent Bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

Pauli Exclusion Principle

An atomic orbital may describe at most two electrons, each with opposite spin direction

Hydrocarbons

Compounds composed of only carbon and hydrogen

Ionic Bond

Formed when one or more electrons are transferred from one atom to another

Atomic Radii

Half the distance between the nuclei of identical atoms that are bonded together

Law of Conservation of Mass

Matter is not created nor destroyed in any chemical or physical change

Oxidation Number

Positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable

Oxidation Numbers

Shows how many electrons can be shared, lost or gained to become stable; you cancel out the valence numbers to make the compound

Arrhenius acid

a substance that increases the concentration of hydronium ions in aqueous solution

Ionization Energy

The amount of energy required to remove an electron from an atom

Arrhenius base

a substance that increases the concentration of hydroxide ions in aqueous solution

Valence Electrons

The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.

London Dispersion Forces (LDF)

The intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles

Stoichiometric Coefficient

The multiplying numbers assigned to the species in a chemical equation in order to balance the equation

Formal Charge

The number of valence electrons in an isolated atom minus the number of electrons assigned to the atom in the Lewis structure

Law of Conservation of Energy

The rule that energy cannot be created or destroyed

Chemistry

The study of the properties of matter and how matter changes

Solute

a substance that is dissolved in a solution.

VSEPR theory

Valence-shell electron-pair repulsion theory; because electron pairs repel, molecules adjust their shapes so that valence electron pairs are as far apart as possible

Theory

a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.

Hypothesis

a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation

Unidentate

a type of ligand that can form one coordinate bond with ions

Combination Reaction

a chemical change in which two or more substances react to form a single new substance

Covalent Compound

a chemical compound formed by the sharing of electrons

Empirical Formula

a chemical formula showing the ratio of elements in a compound rather than the total number of atoms

Metathesis Reaction

a chemical reaction in which an element or radical in one compound exchanges places with another element or radical in another compound.

Redox Reaction

a chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.

Structural Formula

a formula that shows the arrangement of atoms in the molecule of a compound.

State Function

a function that depends only on the initial and final states of a system, not on the path in between.

Carbonyl Groups

a functional group present in aldehydes and ketones and consisting of a carbon atom double-bonded to an oxygen atom.

Molecules

a group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

System

a group of parts that work together as a whole

Primary Standard

a highly purified solid compound used to check the concentration of the known solution in a titration

Solution

a homogeneous mixture of two or more substances

Polymers

a large molecule made up of chains or rings of linked repeating subunits, which are called monomers

pH

a measure of hydrogen ion concentration, a measure of the acidity or alkalinity of a solution. The pH scale usually ranges from 0 to 14. Aqueous solutions at 25°C with a pH less than 7 are acidic, while those with a pH greater than 7 are basic or alkaline.

Space Filling Model

a model of a molecule showing the relative sizes of the atoms and their relative orientations

Ball and Stick Model

a molecular model that distorts the sizes of atoms but shows bond relationships clearly

Ligand

a molecule that binds specifically to another molecule, usually a larger one.

Chiral Molecules

a molecule that is not super-imposable upon its mirror image or lacks an internal plane of symmetry

Dipole

a pair of equal and oppositely charged or magnetized poles separated by a distance.

Chemical Properties

a property or characteristic of a substance that is observed during a reaction in which the chemical composition or identity of the substance is changed

Physical Properties

a property or characteristic that is measurable and whose value describes a state of a physical system

Extensive Properties

a property that depends on the amount of matter in a sample

Decomposition Reaction

a reaction in which a single compound breaks down to form two or more simpler substances

Displacement Reaction

a reaction in which one element replaces a similar element in a compound

%RSD

a relative numerical representation of precision of a set of measurements

Experiment

a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact.

Titrant

a solution of known concentration that is used to titrate a solution of unknown concentration

Law

a statement of fact, deduced from observation, to the effect that a particular natural or scientific phenomenon always occurs if certain conditions are present.

Constitutional Isomers

compounds that have the same molecular formula but different connectivity.

Positional Isomers

constitutional isomers that have the same carbon skeleton and the same functional groups but differ from each other in the location of the functional groups on or in the carbon chain.

Coordination Isomers

denote an exchange of ligands between the coordination spheres of the cation and anion

Amides

derivatives of carboxylic acids in which the hydroxyl group has been replaced by an amine or ammonia

Linkage Isomers

different ligands or different attachment of ligands

Stereo Isomers

each of two or more compounds differing only in the spatial arrangement of their atoms.

Geometric Isomers

each of two or more compounds which differ from each other in the arrangement of groups with respect to a double bond, ring, or other rigid structure.

Isomers

each of two or more compounds with the same formula but a different arrangement of atoms in the molecule and different properties.

Optical Isomers

each of two or more forms of a compound which have the same structure but are mirror images of each other and typically differ in optical activity.

Isotopes

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei, and hence differ in relative atomic mass but not in chemical properties; in particular, a radioactive form of an element.

Lewis acid

electron pair acceptor

Lewis base

electron pair donor

Hund's Rule

electrons occupy orbitals of the same energy in a way that makes the number of electrons with the same spin direction as large as possible

First Law of Thermodynamics

energy can be transferred and transformed, but it cannot be created or destroyed.

Molecular Equations

equations that describe the chemicals put into the water and the product molecules

Surroundings

everything outside the system

Ionization Isomers

exchange ion between ligand and anion

Hydration Isomers

exchange water as ligand and hydrate

Sugars

have five hydroxyl groups (−OH) and a carbonyl group (C=O) and are cyclic when dissolved in water

Chiral Centers

have four different groups attached to the central carbon

Donor Atom

the atom in a ligand that is bound directly to the metal atom

Law of Multiple Proportions

if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Intensive Properties

independent of the amount of substance present

Structural Isomers

involve different atoms to ligand bonding sequences

Net Ionic Equations

ionic equations that include only the particles that participate in the reaction

Entantiomers

isomers that are mirror images of each other

Fats

lipids that are solid at room temperature

Aufbrau Principle

lower energy orbitals fill before higher energy orbitals

wt%

mass of solute/total mass of solution x100

Secondary Standard

not as pure as primary, concentration is adjusted to an exact concentration against a primary standard

Ionic Radii

radius of an ion

Electronic Geometry

refers to the position of all electrons in a molecule, whether bonding or nonbonding

Precision

refinement in a measurement, calculation, or specification, especially as represented by the number of digits given.

Exothermic

releases heat

Bond Line Formula

represents organic compounds with lines instead of drawing out carbon chains and omits hydrogens

Coordination Sphere

the central metal plus the ligands bound to it

Melting

the change in state from a solid to a liquid

Evaporation

the change of a substance from a liquid to a gas

Deposition

the change of state from a gas directly to a solid

Condensation

the change of state from a gas to a liquid

Freezing

the change of state from a liquid to a solid

Accuracy

the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.

Polarizability

the ease with which the electron distribution in the atom or molecule can be distorted

Kinetic Energy

the energy an object has due to its motion

Electron Affinity

the energy change that occurs when an electron is acquired by a neutral atom

Heat

the energy transferred between objects that are at different temperatures

Enthalpy of Formation

the enthalpy change that accompanies the formation of a substance from the most stable forms of its component elements

Enthalpy

the heat content of a system at constant pressure

Specific Heat Capacity

the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).

Valence Bond Theory

the idea that covalent bonds are formed when orbitals of different atoms overlap

Atomic Mass

the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

Dipole Moment

the mathematical product of the separation of the ends of a dipole and the magnitude of the charges.

Heat Capacity

the number of heat units needed to raise the temperature of a body by one degree.

Coordination Number

the number of ligands attached to the central ion

Molarity

the number of moles of solute per liter of solution

Atomic Number

the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table

Hess's Law

the overall enthalpy change in a reaction is equal to the sum of enthalpy changes for the individual steps in the process

Percent Composition

the percent by mass of each element in a compound

Standard State Matter

the phase of an element at standard pressure and temperature

Equivalence Point

the point at which the two solutions used in a titration are present in chemically equivalent amounts

End Point

the point in a titration at which an indicator changes color

Sublimation

the process in which a solid changes directly into a gas

Percent Yield

the ratio of the actual yield to the theoretical yield expressed as a percent

Stoichiometry

the relationship between the relative quantities of substances taking part in a reaction or forming a compound, typically a ratio of whole integers.

Thermal Equilibrium

the state of two or more objects or substances in thermal contact when they have reached a common temperature

Solvent

the substance in which the solute dissolves

Limiting Reactant

the substance that controls the quantity of product that can form in a chemical reaction

Internal Energy

the sum of the kinetic and potential energies of all particles in the system

Molecular Geometry

the three-dimensional arrangement of atoms in a molecule

Exact Numbers

those whose values are known exactly

Condensation Polymerization

type of polymerization in which the formation of a small molecule, such as water, accompanies the extension of the polymer chain

trans

used to describe two groups that are on opposite sides of a ring

cis

used to describe two groups that are on the same side of a ring

mer

used to form words relating to chemical structure, denoting parts of a molecule (monomer, dimer)

Ionic Equations

used to show details of reactions that involve ions in an aqueous solution

fac

used when three identical ligands occupy one face of an octahedron