Chemistry (5245) Praxis

thermochemical equation

A Thermochemical Equation is a balanced stoichiometric chemical equation that includes the enthalpy change, Î"H

barometer

A barometer is a scientific instrument used in meteorology to measure atmospheric pressure

buffer

A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa

calorimeter

A calorimeter is an object used for calorimetry, or the process of measuring the heat of chemical reactions or physical changes as well as heat capacity

carboxylic acid

A carboxylic acid /ËŒkÉ'Ë?rbÉ'kˈsɪlɪk/ is an organic compound that contains a carboxyl group

chemical bonds

A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds

compound

A chemical compound is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds

covalent bond

A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms

liquid

A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure

Physical properties

A physical property is any property that is measurable, whose value describes a state of a physical system

polynucleotide

A polynucleotide molecule is a biopolymer composed of 13 or more nucleotide monomers covalently bonded in a chain

intermediates

A reaction intermediate or an intermediate is a molecular entity that is formed from the reactants and reacts further to give the directly observed products of a chemical reaction

reactants

A reagent /riˈeɪdÊ'É™nt/ is a substance or compound added to a system to cause a chemical reaction, or added to see if a reaction occurs

reducing agent

A reducing agent is an element or compound that loses an electron to another chemical species in a redox chemical reaction

saturated

A saturated fat is a type of fat, in which the fatty acids all have single bonds

single displacement reaction

A single-displacement reaction, also named single-replacement reaction, is a reaction by which a substance replaces a substance which replaces a substance in an element

system

A system is a set of interacting or interdependent component parts forming a complex/intricate whole

tRNA

A transfer RNA is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length, that serves as the physical link between the mRNA and the amino acid sequence of proteins

absolute zero

Absolute zero is the lower limit of the thermodynamic temperature scale, a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0

alpha particle

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus

atmosphere

An atmosphere is a layer of gases surrounding a planet or other material body, that is held in place by the gravity of that body

electrochemical cell

An electrochemical cell is a device capable of either generating electrical energy from chemical reactions or facilitating chemical reactions through the introduction of electrical energy

exothermic reaction

An exothermic reaction is a chemical reaction that releases energy by light or heat

ideal gases

An ideal gas is a theoretical gas composed of many randomly moving point particles that do not interact except when they collide elastically

organic compound

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon

calorie

Calories are units of energy

Celsius scale

Celsius, also known as centigrade, is a scale and unit of measurement for temperature

decomposition reaction

Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds

diffusion

Diffusion is the net movement of molecules or atoms from a region of high concentration to a region of low concentration

effusion

Effusion is the process in which a gas escapes through a hole of diameter considerably smaller than the mean free path of the molecules

Heating things up increases the entropy

Entropy is a measure of the energy of a system that is unavailable for doing useful work

filtration

Filtration is any of various mechanical, physical or biological operations that separate solids from fluids by adding a medium through which only the fluid can pass

geothermal

Geothermal energy is thermal energy generated and stored in the Earth

Glucose

Glucose is a sugar with the molecular formula C6H12O6

specific heat capacity

Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to an object to the resulting temperature change

chemical equilibrium

In a chemical reaction, chemical equilibrium is the state in which both reactants and products are present in concentrations which have no further tendency to change with time

partial pressure

In a mixture of gases, each gas has a partial pressure which is the hypothetical pressure of that gas if it alone occupied the volume of the mixture at the same temperature

quaternary structure

In biochemistry, quaternary structure is the number and arrangement of multiple folded protein subunits in a multi-subunit complex

rate determining step

In chemical kinetics, the overall rate of a reaction is often approximately determined by the slowest step, known as the rate-determining step or rate-limiting step

nucleons

In chemistry and physics, a nucleon is one of the particles that make up the atomic nucleus

mixture

In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically

reaction mechanism

In chemistry, a reaction mechanism is a step by step sequence of elementary reactions by which overall chemical change occurs

reaction quotient

In chemistry, a reaction quotient is a function of the activities or concentrations of the chemical species involved in a chemical reaction

chemical energy

In chemistry, chemical energy is the potential of a chemical substance to undergo a transformation through a chemical reaction to transform other chemical substances

coordination number

In chemistry, crystallography, and materials science the coordination number of a central atom in a molecule or crystal is the number of its near neighbors

Hybridization

In chemistry, hybridization is the concept of mixing atomic orbitals into new hybrid orbitals suitable for the pairing of electrons to form chemical bonds in valence bond theory

molar mass

In chemistry, the molar mass M is a physical property defined as the mass of a given substance divided by the amount of substance

Amorphous solids

In condensed matter physics and materials science, an amorphous or non-crystalline solid is a solid that lacks the long-range order characteristic of a crystal

ligand

In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex

crystal structure

In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material

Element

In mathematics, an element, or member, of a set is any one of the distinct objects that make up that set

fission

In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts

beta decay

In nuclear physics, beta decay is a type of radioactive decay in which a beta ray, and a respective neutrino are emitted from an atomic nucleus

fusion

In nuclear physics, nuclear fusion is a nuclear reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles

hydrocarbons

In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon, and thus are group 14 hydrides

alkene

In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon-carbon double bond

functional group

In organic chemistry, functional groups are specific groups of atoms or bonds within molecules that are responsible for the characteristic chemical reactions of those molecules

Work

In physics, a force is said to do work if, when acting there is a displacement of the point of application in the direction of the force

work

In physics, a force is said to do work if, when acting there is a displacement of the point of application in the direction of the force

Energy

In physics, energy is a property of objects which can be transferred to other objects or converted into different forms

heat

In physics, heat is energy that spontaneously passes between a system and its surroundings in some way other than through work or the transfer of matter

potential energy

In physics, potential energy is energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors

kinetic energy

In physics, the kinetic energy of an object is the energy that it possesses due to its motion

triple point

In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases of that substance coexist in thermodynamic equilibrium

Thermal energy

In thermodynamics, thermal energy refers to the internal energy present in a system due to its temperature

James Watson

James Dewey Watson is an American molecular biologist, geneticist, and zoologist, best known as one of the co-discoverers of the structure of DNA in 1953 with Francis Crick

Lewis dot structure

Lewis structures show each atom and its position in the structure of the molecule using its chemical symbol

London dispersion force

London dispersion forces are a type of force acting between atoms and molecules

Melting

Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid

metal bond

Metallic bonding arises from the electrostatic attractive force between conduction electrons and positively charged metal ions

pressure

Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed

Proteins

Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues

real gases

Real gases are non-hypothetical gases whose molecules occupy space and have interactions; consequently, they adhere to gas laws

redox reaction

Redox is a chemical reaction in which the oxidation states of atoms are changed

solid

Solid is one of the four fundamental states of matter

equilibrium constant

The equilibrium constant of a chemical reaction is the value of the reaction quotient when the reaction has reached equilibrium

equivalence point

The equivalence point, or stoichiometric point, of a chemical reaction is the point at which chemically equivalent quantities of acid and base have been mixed

alkyl halide

The haloalkanes are a group of chemical compounds derived from alkanes containing one or more halogens

ideal gas law

The ideal gas law is the equation of state of a hypothetical ideal gas

joule

The joule , symbol J, is a derived unit of energy in the International System of Units

limiting reactant

The limiting reagent in a chemical reaction is the substance that is totally consumed when the chemical reaction is complete

primary structure

The primary structure of a peptide or protein is the linear sequence of its amino acid structural units and partly comprises its overall biomolecular structure

rate law

The rate law or rate equation for a chemical reaction is an equation that links the reaction rate with concentrations or pressures of reactants and constant parameters

structural formula

The structural formula of a chemical compound is a graphic representation of the molecular structure, showing how the atoms are arranged

endothermic reaction

The term endothermic process describes a process or reaction in which the system absorbs energy from its surroundings; usually, but not always, in the form of heat

phase change

The term phase transition is most commonly used to describe transitions between solid, liquid and gaseous states of matter, and, in rare cases, plasma

phase transition

The term phase transition is most commonly used to describe transitions between solid, liquid and gaseous states of matter, and, in rare cases, plasma

titrant

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte

VSEPR theory

Valence shell electron pair repulsion theory is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms

Energy transformation

energy transformation or energy conversion is the process of changing one form of energy to another form of energy

Gas

gas is one of the four fundamental states of matter

half

life-Half-life is the time required for a quantity to reduce to half its initial value