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chapter 13 chem
| Question | Answer |
|---|---|
| to move; Describes the behavior of gases in terms of energy, size, and motion of their particles | kinetic |
| all matter consists of tiny particles that are in constant motion | kinetic theory |
| what are Three assumptions are made regarding the kinetic theory and gases | 1- the particles in a gas are considered to be small, hard spheres with an insignificant volume. 2-the motion of the particles in a gas is rapid, constant and random 3-All collisions between particles in a gas are perfectly elastic. |
| what Two factors determine the kinetic energy(KE) of a particle | mass and velocity |
| reflects both the speed and direction of motion | velocity |
| In a sample of gas, what factors are the same and what is different? | All particles have the same mass All particles do not have the same velocity Do not have same KE |
| Measure of the average kinetic energy of the particles in a sample of matter | temperature |
| results from the force exerted by a gas per unit surface area of an object. | gas pressure |
| How does a balloon keep its shape? | The gas pressure is a result of billions of rapidly moving particles in a gas simultaneously colliding with an object |
| Force per unit area | pressure |
| The force exerted by air at any point on the earths surface | atmospheric pressure |
| how does atmospheric pressure vary at different points of the earth | Higher altitude lower atmospheric pressure |
| If there are no particles present then no collision can occur. So there is no pressure, the result is a ________ | vacuum |
| an empty space with no pressure | vacuum |
| why does Air exerts pressure on Earth | because gravity holds particles in air within Earth’s atmosphere |
| the collision of atoms and molecules in the air with objects | atmospheric pressure |
| As you climb a mountain atmospheric pressure decreases because the_______ of the atmosphere decreases. | density |
| device used to measure atmospheric pressure | barometer |
| SI unit for pressure | Pascal (Pa) |
| _______________ and ___________ are also used as measurements of pressure | Millimeters of mercury (Mm Hg) and atmospheres (atm) |
| ____ atm = _____ mmHg = _____ kPa | 1, 760, 101.3 |
| What properties of gases make it possible for an air filled flotation device to work? | Low Density Compression and expansion Diffusion and effusion |
| compares mass of an object to its volume | density |
| reduce the volume; Large amount of empty space between air particles allows the air to be easily pushed into a smaller volume | compress |
| Air particles fills the available space | expansion |
| ________ ________ of gas particles causes the gases to mix until they are evenly distribute | Random motion |
| Movement of one material through another | diffusion |
| in diffusion, there is a Movement from an area of ________ concentration to an area of ______ concentration | higher; lower |
| in diffusion, Heavier particles are ______ Light particles are _____ | slower, faster |
| Gas escapes through a tiny opening | effusion |
| in effusion there is an Inverse relationship between ______ ______ and ______ ________ | effusion rate; molar mass |
| Can take the shape of its container; Fixed volume | liquid |
| Liquid molecules don’t have ______ positions | fixed |
| ____________ between liquid particles limit their range of motion | Forces of attraction |
| The density of a liquid is much ________ than that of its vapor at the same conditions | greater |
| why is the density of liquid water and steam different | because of the intermolecular force that holds them together |
| Change in volume is much ______ in a liquid than a gas | smaller |
| liquids can be ________ | compressed |
| A LARGE amount of _________ must be added to even slightly change the volume of a liquid | pressure |
| Ability to flow | fluidity |
| liquid_______ more slowly than a gas at the same temperature | Diffuses |
| liquid is less fluid than gas give an example | Water leak stays in the basement unless the amount of water released exceeds the volume of the basement Gas leak can diffuse through out the house |
| Measure of resistance of a liquid to flow | viscosity |
| viscosity is Determined by the type of _______ ______ involved, the _______ __ ____ _______, and the _______ | intermolecular forces, shape of the particles, temperature |
| The stronger the attractive forces, the_______ the viscosity | higher |
| Viscosity _______ with an increase in temperature | decreases |
| give an example of viscosity and temperature | when you heat up syrup it becomes easier to pour |
| Intermolecular forces _______ have an equal effect on all particles in a liquid | DON’T |
| what are particles in the middle of a liquid attracted to | attracted to particles all around them |
| what are particles on the surface of a liquid attracted to | no attraction from above to balance the attractions from below, Net attractive force pulling down on particles at the surface |
| The stronger the attractions between particles, the _______ the surface tension | greater |
| force of attraction between like molecules | cohesion |
| force of attraction between different molecules | adhesion |
| The movement of a liquid upward | capillary action |
| give an example of capillary action | Example: Paper towels and diapers Water is drawn into the narrow spaces between the cellulose fibers by capillary action |
| conversion of liquid to gas | vaporization |
| when vaporization occurs at the surface of a liquid that is not boiling. | evaporation |
| During evaporation only the molecules with a certain ______ ________ ______ can escape the surface of the liquid | minimal kinetic energy |
| measure of the force exerted by a gas above a liquid | vapor pressure |
| conversion of gas to liquid | condensation |
| the temperature at which the vapor pressure of a liquid is equal to the external pressure on the liquid | boiling point |
| Normal boiling point | 101.3 kPa |
| Change in altitude affects the boiling point because atmospheric pressure is_______ at higher temperatures | lower |
| sea level water boils at 100 C but in denver it boils at ____ | 95 C |
| A mole of a solid particle has as much ______ _______ as a mole of liquid particles | kinetic energy |
| why do solids have a definite shape a volume? | In a solid there are strong attractive forces between particles These forces limit the movement to vibrations in a fixed location Particles are packed closer together |
| temperature at which a solid turns into a liquid | melting point |
| temperature at which a liquid turns into a solid | freezing point |
| Crystal-particles are arranged in an orderly repeating 3-D pattern called a ______ _______ | crystal lattice |
| smallest arrangement of connected points that can be repeated in three directions to form the lattice | unit cell |
| two or more different molecular forms of an element | allotropes |
| Solid in which the particles are not arranged in a regular repeating pattern ; lacks an ordered structure | amorphous solids |
| when do amorphous solids form usually? | when a molten material cools to quickly example: Glass, rubber and many plastics, Glasses can be considered super-cooled liquids |
| Phase changes that require energy | melting, vaporization, sublimation |
| What does happen to ice cubes in a glass of ice water? | Heat flows from the water to the ice Heat- transfer of energy from an object at a higher temp to an object at a lower temp Energy breaks the hydrogen bonds and causes the ice to enter its liquid phase |
| Temperature at which the forces holding a crystal lattice together are broken and becomes a liquid | melting point |
| The process by which a liquid changes to a gas or vapor | vaporization |
| When vaporization occurs only at the surface of a liquid Method by which your body controls its temp | evaporation |
| As temperature________ more molecules are able to escape from the liquid | increases |
| Pressure exerted by a vapor over a liquid (closed container) | vapor pressure |
| Temperature when the vapor pressure of liquid equal s the atmospheric pressure Molecules have enough energy to vaporize | boiling point |
| Process by which a solid changes directly to a gas | sublimation |
| give some examples of sublimation | Solid iodine Solid carbon dioxide(dry ice) Solid air fresheners |
| Phase changes that Release Energy | Condensation Deposition Freezing |
| The process by which a gas or a vapor becomes liquid Reverse of vaporization Loses energy, velocity is reduced | condensation |
| Process by which a substance changes from a gas or vapor to a solid without becoming a liquid first Reverse of sublimation Example: snowflakes | deposition |
| Heat is removed, molecules lose KE and their velocity decreases When enough energy has been removed, the molecules will stay in fixed position | freezing |
| Temperature at which a liquid is converted into a crystalline solid | freezing point |
| A graph of pressure versus temperature that shows in which phase a substance exists under different conditions of temperature and pressure | phase diagrams |
| The point on a phase diagram that represents the temperature and pressure at which three phases of a substance can coexist | triple point |
| what happens to boiling point when you reach higher altitudes? | High altitudes have lower atmospheric pressure. higher up into the atmosphere= lower air pressure.since the boiling point occurs only when the vapor pressure of the liquid=atmospheric pressure, the boiling point of water will be lower |