General Chemistry I
Terms
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- Matter
- Physical material of the universe- anything that has a mass and occupies space
- Elements
- Cannot be decomposed into simpler substances
- Atoms
- The basic building blocks of matter; the smallest units ofan element that can combine with other elments
- Molecules
- Two or more atoms are joined together in specific shapes
- States of Matter
- Gas, liquid, or solid
- Liquid
- Has a distinct volume independent of its contaner but has no specific shape
- Gas
- Has no fixed volume or shape
- Solid
- Has a definite shape and volume
- Pure Substance
- Matter thatas distinct properties and a composition that doesn't vary from sample to sample.
- Compounds
- Substances composed of twoor more elements
- Mixtures
- combinateions of two or more substances in which each substance retains its own chemical identity
- Law of Constant Composition
- The observaion that the elemental composition of a pure compound is always the same
- Solutions
- Homogenous mixtures
- Physical Properties
- Properties that can be measured without changing the identity and composition of the substance.
- Chemical Properties
- Properties hat describe the way a substance may change or reat to form other substances
- Intensive Properties
- Propeties that do not depend on the amount of the sample being examined.
- Extensive Properties
- Properties of substances that depend on the quantity of the sample and include measurements of mass and volume.
- Physical Changes
- A change in which a substance changes its physical appearance, but not its composition.
- Changes of State
- Physical changes from different states (for example: liquid to solid)
- Chemical Changes
- Changes nwhich a substance is transformed into a chemically different substance.
- Metric System
- The units of measurement used for scientific measurements.
- Precision
- Ameasure of how closely individual measurements agree with one another
- Accuracy
- How closely individual measurements agree with the correct value
- Conversion Factor
- A fraction whose numerator and denominator are the same quantity expressed in different units
- Scientific Method
- A dynamic process used to answe questions about our physical world
- Subatomic particles
- Comprise atoms; some are charged
- Cathode rays
- Their behavior in magnetic and electrical fields led to the discovery of the electron
- Radioactivity
- The spontaneos emission of radiation by atoms
- Nucleus
- The dense, positively charged center of a atom
- Protons
- Positively charged subatomic particle
- Neutrons
- Neutral subatomic particle
- Electons
- Negatively charged subatomic particle
- Atomic Number
- The number of protons
- Isotopes
- Atoms of a given element that differ in the number of nuetrons, and consequently in mass
- Mass Number
- Total number of protons plue neutrons in the atom
- Nuclide
- An atom of a specific isotope
- Atomic Weight
- Average atomic mass of each element
- Periodic Table
- The arrangelment of elements in order of increasing atomic number
- Group
- The elements in a column of the periodic table
- Metallic Elements
- All the elements on the lef side and in the middle of the periodic table
- Molecule
- An assembly of two or moe atoms tightly bound together
- Diatomic Molecule
- A molecule that is made up of two atoms
- Molecular Formulas
- Chemical formulas tha indicate the actual numbers and types of atoms in a molecule
- Empirical Formulas
- Chemical formulas that give only the relative number of atoms of each type in a molecule
- Structural Formula
- Shows which atoms are attached to which within the molecule
- Ion
- A charged particle
- Cation
- An ion with a positive charge
- Anion
- An ion with a negative charge
- Ionic Compound
- A compound that contains both positively and negatively charged ions
- Chemical Nomenclature
- The naming of substances
- Organic Chemistry
- The sudy of compounds of carbon
- Hydrocarbons
- Organic compounds only containing carbon and hydrogren
- Stoichiometry
- The study of the quantitative relationships between chemical formulas and chemical equations
- Law of Conservation of Mass
- The total mass of the products of a chemical reacton is the same as the total mass of the reactants.
- Chemical Equation
- Shows the equal numbers of atoms of each element oneach side of the equation
- Combination Reactions
- Two reactants combine to form one product
- Decomposition Reaction
- A single reactant forms two or more products
- Combustion Reaction
- A reaction in which a hydrocarbon reacts with oxygen to form carbon dioxide and water.
- Formula Weight
- Weight of the compound that equals the sum of the atomic weighs of the atoms in its formula
- Mole
- Avogradro's number of formula units of that substanc
- Avogadro's Number
- 6.02 x 10^23
- Limiting Reactant
- The reactant that is completey consumed in a reaction
- Theoretical Yield
- The quantity of product calculated to form when all of the limiting reagent reacts
- Aqueous Solutions
- Solutions in which water is the dissolving medium
- Solvent
- The component of the solution that is in the greater quantity
- Solutes
- All other components of a solution
- Electrolyte
- Any substance whose aqueos soluton contains ions
- Nonelectrolyte
- Any substance that forms a solution contaiing no ions
- Strong Electrolytes
- Those electrolytes that are present in solution entirely as ions
- Weak Electrolytes
- Those electrolytes that are present partly as molecules
- Precipitation reactions
- Those in which an insoluble product forms
- Precipitate
- An insoluble product
- Solubility
- The amount of a substnc that dissolves in a given quantity of solvent
- Metahesis reactions
- Reaction such as precipitation reaction, in which cations and annions appear to exchange partners
- Moleclar equation
- Used when the complete chemical formulas of all reactants and products are used
- Complete Ionic Equation
- Shows all dissolved strong electrolytes as their component ions
- Net Ionic Equation
- An equation in which those ions that go through te reaction unchanged are omitted
- Acids
- Proton donors
- Bases
- Proton acceptors
- Oxidation
- The loss of electrons by a substance
- Reductions
- The gain of electrons by a substance
- Displacement Reactions
- The redox reactions between metals and acides and between metals and salts
- Activity Series
- A list of metals arranged in order of decreasing ease of oxidation
- Molarity
- The number of moles of solute per liter of solution
- Titration
- Combine a solution on known concentration with a solution of unknown concentration
- Thermodynamics
- The study of energy and its transformations
- Thermochemistry
- The transformations of enrgy- especially heat- during chemical reactions
- Kinetic Energy
- Energy due to the motion of the object
- Kintetic Energy
- Energy due to the motion of the object
- Potential Enrgy
- Energy that an object possesses by virtue of its position relative to other objects
- Calorie
- The quantity of energy necessary to increase the temperateure of 1g of water by 1 degree C
- System
- Specific amount of matter
- Surroundings
- Everything outside of a system
- Work
- Energy expanded to move an object against a force
- Heat
- The enrgy that is transferred from a hotter object to a colder one
- Energy
- The capacity to do work or transfer heat
- Interal energy
- The sum of all the kinetic and potential energies of its component parts
- First Law of Thermodynamics
- The change in the internal system of a system is the sum of the heat transferred into or out of the system and the work, done on or by the system
- Endothermic
- Process in which the system absorbs heatfrom the surroundings
- Exothermic
- Process in which the system releases heat to the surroundings
- Pressure-volume work
- Performed when a gas is produced or consumed in a chemical reaction occuring at constant pressure
- Enthalpy of reaction
- The enthalpy of the products minus the enthalpy of the reactants
- Calorimeter
- Measures the temperature change accompanying a process
- Heat Capacity
- The amount of heat required to raise its temperature by I degree kelvin
- Molar Heat Capacity
- The heat capacity of one mole of a pure substance
- Specific het
- The heat capacity of one gram of a substance
- Bomb Calorimeer
- Used to measure the heat evolved in combustion reactions
- Hess's Law
- If a reaction is carried out in aseries of stems, the change in heat for the reaction will be equal tothe sum of enthalpy changes for the steps.
- Enthalpy of Formation
- The enthalpy change for the reaction in which the substance is formed from its constituent elements
- Standard Enthapy
- Enthalpy change when all reactants and productes are at 1 atm pressure and a specific temperature
- Standard Enthalpy of Formation
- The chang in enthalpy for the reaction that forms 1 mol of the substance from its elements with all reactants and products at 1 atm pressure and usually 298 K
- Electronic Structure
- Describes the energies and arrangement of electrons around the atom.
- Quantum of Energy
- The minimum amount of radiant energy that an object can gain or lose
- Planck's Constant
- h= 6.63 x 10^-34 J-s
- Photoelectric Effect
- The emission of electrons from metal surfaces from light
- Spectrum
- Produced by a dispersion of radiation into its component wavelengths
- Continuous Spectrum
- If a sepctrum contains all wavelengths
- Line Spectrum
- If a spectrum only contains specific wavelengths
- Ground State
- The lowest energy of a hydrogen atom
- Heisenberg's Uncertainty Principle
- There is an inheret limit to the accuracy with which the position of momentum of a particle can be measured simultaneously.
- Wave functions
- Mathematical functions that describe the behavior of the electron in the quantum mechanical model of the hydrogen atom