# Final

 A property of materials that is related to the ease with which they flow. It is a qualitative observation but can be made quantitative
 Viscosity
 The shape, size, flexibility, forces of attraction, etc. of the molecules determine
 How easily (or not easily) the liquid flows
 Force times distance divided by area times velocity
 Units of velocity
 The viscosity usually ________ with an ________ in temperature for liquids and soft solids
 Decreases, increase
 The viscosity of gases usually _______ with ________ temperature
 Increases, increasing
 If the volume of a mixture is equal to the sum of the volumes of the components mixed, it is said that the volumes are ______ for this mixture
 A form of thermal energy that flows spontaneously from an area of high temperature to an area of low temperature.
 Heat
 Two objects that start out at different temperatures will reach _______ when brought into contact with one another because heat flows from the object with the higher temperature to the object with lower temperature
 Equilibrium temperature
 Heat flow into a substance causes the temperature of that substance to rise unless a phase change (solid to liquid, etc) is occurring. The amount of heat required to raise one gram of a substance one degree C.
 Specific heat
 The amount of heat required to raise the temperature of one gram of water by one degree C
 Calorie
 The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit
 British thermal unit
 The space inside a sealed, insulated container. No heat (or matter) goes into or out of the container
 Isolated system
 Systems that allow energy to go into and out of them but no matter to go into or out of them
 Closed systems
 Systems that allow both energy and matter to transfer into and out of them
 Open systems
 Gas molecules occupy negligible volume compared to the empty space between the molecules and the intermolecular forces of attraction and repulsion are insignificant. If molecules of liquid water move fast enough, they could break free from the attraction of other liquid water molecules and a gas molecule will form, as long as the temperature remains fixed, regardless of if the water is at its boiling point
 Kinetic molecular theory
 Force per unit area or the total force applied divided by the total surface area over which that force is applied
 Pressure
 The pressure required to support a column of mercury to a height of 760.0 mm
 One atmosphere (atm)
 P is the pressure exerted by the sample of gas measure in atmospheres, V is the volume of the sample in liters, T is the temperature in Kelvin, and n is the number of moles in the sample
 Ideal Gas Law
 Maintaining constant temperature amount of moles in a sealed piston, the volume of the sample can be systematically varied. As pressure increases, volume decreases
 Boyle’s Law
 As Pressure increases, Temperature increases at constant volume and moles
 Gay-Lussac’s Law
 As Volume increases, Temperature increases at constant pressure and moles
 Charles’ Law
 The sum of the partial pressures of the component gases in the mixture
 Dalton’s law of partial pressures
 The sum of the partial volumes of the individual gases that would occupy at the same pressure and temperature
 Amagat’s Law
 The heat of vaporization of a liquid generally _______ as the temperature of vaporization _______
 Increases, decreases
 The amount of heat required to evaporate a certain amount of water
 Heat of vaporization of water
 The temperature at which its vapor pressure is equal to the pressure exerted on the liquid
 Boiling point of a liquid
 The temperature at which its vapor pressure is equal to 760 mm Hg
 Normal Boiling point of a liquid
 Liquids can be heated to a temperature above their boiling point and yet no boiling occurs
 Superheating
 Arises from conflict between attractive energy (enthalpy) and tendency toward disorder (entropy)
 Supercooling
 Solids at room temperature, but do not exist as discrete molecules
 Ionic compounds
 Formed by the reaction of non-metals with non-metals
 Covalent compounds
 Exist as discrete molecules. Can exist as solids, liquids, or gases at room temperature (NO, SO3, CH4, PCl3)
 Molecular covalent compounds
 Do not exist discrete molecules. All the atoms are bound together to make a giant molecules. Always solids at room temperature. (SiC and SiO2)
 Network covalent compounds
 Metals do not react with other metals to form compounds. They form mixtures with each other
 Alloys
 Forces between the atoms in the molecule
 Intramolecular forces
 Forces between different molecules
 Intermolecular forces
 The force of attraction between two oppositely charged ions is ________ than the attraction between two neutral molecules
 Much stronger
 In order to convert an ionic compound into a liquid, the very strong forces between the positive and negative ions must be partially overcome and the ions much be able to move while being attracted strongly to each other. Heating adds ________ to the particles in the solid
 Energy
 In a covalent solid, the molecules are held in a geometric pattern by intermolecular attractions between the molecules
 Van der Waal’s forces
 For covalent compounds, the amount of energy needed to partially overcome the intermolecular attractions is significantly ______ on the average than is needed fro ionic compounds
 Less
 One must find the temperature at which a solid and the liquid phases exist together in equilibrium
 Freezing point
 When both solid and liquid are present, the temperature ______ when heat is removed and some liquid freezes until all the liquid is frozen
 Remains constant
 Sometimes a liquid will cool below its freezing point without freezing
 Supercooling
 Moving electrical charge
 Electrical current
 If two objects are at two different temperatures and then come into contact with one another, they will reach equilibrium temperature because the heat from the object will flow to the object with lower temperature until they have the same temperature
 Zeroth Law of Thermodynamics
 A liter of gas A contains the same number of molecules of A as the number of molecules of B in a liter of gas B provided the temperature and pressure are the same for the liter of a and the liter of B