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Chemistry Exam! :/
Second semester exam vocab
Question | Answer |
---|---|
Kinetic-molecular theory | Based in the idea that particles of matter are always in motion |
Ideal gas | A hypothetical gas that perfectly fits all the assumptions of the kinetic-molecular theory. |
Elastic collision | One in which there is no net loss of total kinetic energy |
Diffusion | Spontaneous mixing of the particles of two substances caused by their random motion |
Effusion | A process by which gas particles pass through a tiny opening |
Real gas | A gas that does not behave completely according to the assumptions of the kinetic-molecular theory |
Fluid | A substance that can flow and therefore take the shape of it's container |
Surface tension | A force that tends to pull adjacent parts of a liquids surface together, thereby decreasing surface tension |
Capillary action | The attraction of the surface of a liquid to the surface of a solid |
Vaporization | The process by which a liquid or solid changes to a gas |
Evaporation | The process by which particles escape from the surface of a non boiling liquid and enter the gas state |
Freezing | The physical change of a liquid to a solid by removal of energy as heat |
Crystalline solids | They consist of crystals |
Crystal | A substance in which the particles are arranged in an orderly, geometric, repeating pattern |
Amorphous solid | One in which the particles are arranged randomly |
Melting | The physical change of a solid to a liquid by the addition of energy as heat |
Melting point | The temperature at which a solid becomes a liquid |
Supercooled liquids | Substances that retain certain liquid properties even at temperatures at which they appear to be solid |
Crystal structure | The total three dimensional arrangement of particles of a crystal |
Unit cell | The smallest portion of a crystal lattice that shows the 3D pattern of the entire lattice |
Phase | Any part of a system that has uniform composition and properties |
Condensation | The process by which a gas changes to a liquid |
Equilibrium | A dynamic condition in which two opposing changes occur at equal rates in a closed system |
Equilibrium vapor | The pressure exerted by a vapor in equilibrium with it's corresponding liquid at a given temperature |
Volatile liquids | Liquids that evaporate readily |
Boiling | The conversion of a liquid to a vapor within the liquid as well as it's surface |
Boiling point | The temperature at which the equilibrium vapor pressure of the liquid equals the atmospheric pressure |
Molar enthalpy of vaporization | The amount of energy as heat that is needed to vaporize one mole of liquid at the liquid's boiling point at constant pressure |
Freezing | The physical change of a liquid to a solid |
Freezing point | The temperature at which the solid and liquid are in equilibrium at 1 atm pressure |
Molar enthalpy of fusion | The amount of energy as heat required to melt one mole of solid at the solid's melting point |
Sublimation | The change of state from a solid directly to a gas |
Deposition | The change of state from a gas directly to a solid |
Phase diagram | A graph of pressure versus temperature that shows the conditions under which the phases of a substance exist |
Triple Point | The temperature and pressure conditions at which the solid, liquid, and vapor of the substance can coexist at equilibrium |
Critical Point | The critical temperature and critical pressure |
Critical Temperature | The temperature above which the substance cannot exist in the liquid state |
Critical Pressure | The lowest pressure at which the substance can exist as a liquid at the critical temperature |
Pressure | The force per unit area on a surface |
Newton | The force that will increase the speed of a one-kilogram mass by one meter per second each second that the force is applied |
Barometer | A device used to measure atmospheric pressure |
Millimeters of mercury | The common unit of pressure symbolized mm Hg |
Atmosphere of pressure | Exactly equivalent to 760 mm Hg |
Pascal | The pressure exerted by a force of one newton acting on an area of one square meter |
Partial Pressure | The pressure of each gas in a mixture |
Dalton's law of partial pressure | The total pressure of a gas mixture is the sum of the partial pressure of the component gases |
Boyle's law | Pressure and volume at a constant temperature are inversely proportional |
Absolute zero | The temperature -273.15 C is given a value of zero in the Kelvin scale |
Charles's law | Temperature and volume at a constant pressure are directly proportional |
Gay-Lussac's law | Pressure and temperature at a constant volume are directly proportional |
Combined gas law | The relationship between pressure, volume, and temperature of a fixed amount of gas |
Avogradro's law | equal volumes of gases at the same temperature and pressure contain equal numbers of molecules |
Gay-Lussac's law of combining volumes of gases | At constant temperature and pressure, the volumes of gaseous reactants and products can be expressed as ratios of small whole numbers |
Standard molar volume of a gas | The volume occupied by one mole of a gas at STP 22.414 10 L |
Ideal Gas Law | The mathematical relationship among pressure, volume, termperature, and the number of moles of a gas |
Ideal gas constant | The constant R |
Graham's law of effusion | The rates of effusion of gases at the same temperature and pressure are inversely proportional to the square roots of their molar masses |
Soluble | Capable of being dissolved |
Solution | A homogenous mixture of two or more substances in a single phase |
Solvent | The solution that dissolves a substance |
Solute | The substance dissolved in a solution |
Suspension | When the particles in a solvent are so large that they settle out unless the mixture id constantly stirred or agitated |
Colloids | Particles that are intermediate in size between those in solutions and suspensions form mixtures called: |
Electrolyte | A substance that dissolves in water to give a solution that conducts eletric current |
Nonelectrolyte | A substance that dissolves in water to give a solution that does not conduct an electric current |
Solution Equilibrium | The physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates |
Saturated Solution | A solution that contains the maximum amount of dissolved solute |
Unsaturated solution | A solution that contains less solute than a saturated solution under the existing conditions |
Supersaturated solution | A solution that contains more dissolve solute than a saturated solution contains under the same condition |
Solubility | The amount of that substance required to form a saturated solution with a specific amount of solvent at a specified temperature |
Hydration | The solution process with water as the solvent |
Immiscible | Liquids that are not soluble in each other |
Miscible | Liquids that dissolve freely in one another in any proportion |
Henry's law | The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid |
Effervescence | The rapid escape of a gas from a liquid in which it is dissolved |
Solvate | A solute particle that is surrounded by solvent molecules |
Enthalpy of solution | The net amount of evergy absorbed as heat by the solution when a specific amount of solute dissolves in a solvent |
Concentration | A measure of the amount of solute in a given amount of solvent or solution |
Molarity | The number of moles of solute in one liter of solution |
Molality | The concentration of a solution expressed in moled of solute perkilogram of solvent |
Dissociation | The separation of ions that occurs when an ionic compound dissolves |
Net ionic equation | The compounds and ions that undergo a chemical change in a reaction in an aqueous solution |
Spectator ions | Ions that do not take part in a chemical reaction and are found in solution both before and after the reaction |
Ionization | When ions are formed from solute molecules by the action of the solvent |
Hydronium ion | The H3O+ ion |
Strong electrolyte | An aqueous solution that conducts electricity well |
Weak electrolyte | An aqueous solution that conducts electricity poorly |
Colligative Properties | Properties that depend on the concentration of solute particles but not on their identity |
Nonvolatile substance | A substance that has little tendency to become a gas |
Molal freezing point | The freezing-points of the pure solvent and a solution of a nonelectrolyte in that solvent, and is directly proportional to the molal concentration of the solution |
Molal boiling point constant | The boiling point elevation of the solvent in a 1-molal solution of a nonvolatile, nonelectroylte solute |
Boiling-point elevation | The difference between the boiling points of the pure solvent and a nonelectrolyte solution of that solvent |
Semipermeable membrane | Allows the passage of some particles while blocking others |
Osmosis | The movement of solvent through a semipermeable membrane from the side of lower solute concentration to the side of higher solute concentration |
Osmotic pressure | The external pressure that must be applied to stop osmosis |
Binary acid | An acid that contains only two different elements: hydrogen and one of the more electronegative elements |
Oxyacid | An acid that is a compound of hydrogen, oxygen, and a third element usually nonmetal |
Arrhenius acid | A water solution containing the hydronium ion (H3O+) |
Arrhenious base | A water solution containing the hydroxide ion (OH-) |
Strong acid | One that contains a large number of hydronium ions (H3O+) |
Weak acid | One that contains a large number of hydroxide ions (OH-) |
Bronstead acid | A proton donor |
Bronstead base | A proton acceptor |
Bonstead acid-base reaction | The process in which protons are transferred from one reactant to another |
Monoprotic acid | An acid that can donate only one proton per molecule |
Polyprotic acid | An acid that can donate more than one proton per molecule |
Diprotic acid | An acid that can donate two protons per molecule |
Triprotic acid | An acid that can donate three protons per molecule |
Lewis acid | An electron pair acceptor |
Lewis base | An electron pair donor |
Lewis acid-base reaction | The formation of one ormore covalent bonds between an electron-pair donor and an electron-pair acceptor |
Conjugate acid | What is formed when a base accepts a proton |
Conjugate base | What is left over when an acid donates a proton |
Amphoteric | Any substance that can react as either an acid or a base |
Neutralization | The reaction of hydronium ions and hydroxide ions to form water molecules |
Salt | An ionic compound composed of a cation from a base and an anion from an acid |
Self-ionization of water | The process that occurs when two water molecules produce a hydronium ion and a hydroxide ion by transfer of a proton |
pH | The negative of the common logarithm of the hydronium ion concentration |
pOH | The negative common logarithm of the hydroxide ion concentration |
Acid-base indicators | Compounds whose colors are sensitive to pH |
Transition interval | The pH range over which an indicator changes color |
pH meter | A device used to measure the pH of a solution |
Titration | The controlled addition and measurement of the amount of solution of known concetration required to react completely with a measure amount of a solution of unknown concentration |
Equivalence point | The point at which the two solution used in a titration are presen in chemically equivalent amounts |
End point | The point in titration at which an indicator changes color |
Standard solution | The solution that contains the precisely known concentration of a solute |
Primary standard | A highly purified solid compound used to check the concentration of the known solution in titration |
Thermochemistry | The study of the transfers of energy as heat that accompany chemical reactions and physical changes |
Calorimeter | The energy absorbe or released as heat in a chemical or physical change |
Temperature | A measure of the average kineitc energy of the particles in a sample of matter |
Joule | The SI unit of heat as well as all other forms of energy |
Heat | The energt transferred between samples of matter because of a difference in their temperatures |
Specific heat | The amount of energy required to raise the temperature of one gram of a sybstance by one degree Celsius of one kelvin |
Enthalpy change | The amount of energy absorbed by a system as heat during a process at constant pressure |
Enthalpy of reaction | The quantity of energy transferred as heat during a chemical reaction |
Thermochemical equation | An equation that includes the quantity of energy released or absorbed as heat during the reaction as written |
Molar enthalpy of formation | The enthalpy change that occurs when one mole of a compound is formed from its elements in their standard state at 25 C and 1 atm |
Enthalpy of combustion | The enthalpy change that occurs during the complete combustion of one mole of a substance |
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 |
Entropy | A measure of the degree of randomness of the particles |
Free energy | The combined enthalpy-entropy function |
Free-energy change | The difference between the change in ethalpy and the product of the Kelvin temperature and the entropy change |
Reaction mechanism | The step-by-step process by which a reaction takes place |
Intermediates | A substance that appears in some steps but not in the net equation |
Homogenous reactoin | A reaction whose reactants and prducts exist in single phase |
Collision theory | The set of assumptions regarding collisions and reactions |
Acivation energy | The energy require to start/begin a reaction |
Activated complex | A transitional structure that results from an effective collision and that persists while old bonds are breaking and new bonds are forming |
Reaction rate | The change in concentration of reactants per unit of time |
Chemical kinetics | The area of chemistry that is concerned with reaction rates and reaction mechanisms |
Heterogenoud reactions | Reactions that involve reactants in two different phases |
Catalyst | A substance that speeds up the rate of a reaction without taking place in the reaction |
Catalysis | The action of a catalyst |
Homogenous catalyst | A catalyst that is in the same phase as all the reactants anf products in a reaction system |
Heterogenous catalyst | A catalyst that is in a differenc phase from that of the reactants |
Composition Stoichiometry | The mass relationships of elements in compounds |
Reaction Stoichiometry | The mass relationships between reactants and products in a chemical reaction |
Mole ratio | A conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction |
Limiting reactant | The reactant that limits the amount of the other reactant that can combine and the amount of product that can form in a chemical reaction |
Excess reactant | The substance that is not used up completely in a reaction |
Theortical yield | The maximum amount of product that can be produced from a given amount of reactant |
Actual yield | The measure anount of a product obtained from a reaction |
Percentage yield | The ratio of the actual yield to the theoretical yield, multiplied by 100 |