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CHM 110 Chapter 05
Chapter 05: Gases, Liquids, and Solids
Question | Answer |
---|---|
how do sd shapes form? | attraction between positive and negative particles, atoms covalent bond structures. 3D shapes then arise because of electrostatic attractions between ions, which counteract kinetic energy. |
kinetic energy increases with _____. | temperature |
the physical state of matter depends on... | the balance between the kinetic energy of particles, and the attractive forces between them |
gaseous state | when the kinetic energy is so high, the attractive forces become too weak to hold bonds together |
liquid state | the the bonds are strong, but not strong enough to keep bonds together |
solid state | when the bonds are stronger than the kenetic energys' pulls. |
in solid, liquid, and gaseous states, the attractive forces between molecules are... | the same |
what are examples of substances that can not exsist in all three states? | wood, paper- they can not melt |
pressure is measured in what ways? | mm Hg, torr, SI unit = pascal, and atm |
What is Boyle's law? What does it state? | PV. The volume of a gas is inversely proportional to the pressure |
What does charles's law state? what is it? | volume of a fixed mass of gas at a constant pressure is directly proportional to the temperature in kelvins. V/T |
What is Gay Lussac's law? | pressure is directly proportional to temperature. P/T |
What is the combined gas law? | (P1V1)/T1 = (P2V2)/T2 |
What is the ideal gas law? | PV=nRT |
What does the kinetic molecular theory state? | 1.) gases consist of particles 2.) the average kinetic energy of gas particles is proportional to the temperature in kelvins 3.) molecules collide with each other 4.) gas particles have no volume 5.) there are no attractive forces between gas particles |
the closer the molecules are to each other... what do they cause? | the greater the effect of the intermolecular forces... condensation and solidfication |
what is condensation? | change from a gas to a liquid |
what is solidfication? | change from a liquid to solid |
what are three types of intermolecular forces? | london dispersion, dipole-dipole, and hydrogen bonding |
what do those bonds determine? | physical properties of molecules like boiling point |
intermolecular forces are _____ than ionic bonds | weaker |
what are london dispersion forces? | extrmeely weak attractive forces between atoms or molecules caused by the electrostatic attraction between temporary induced dipoles |
What makes London Dispersion forces unique? | although they exsist in all forces between all molecules, they are the only forces of attraction between nonpolar molecules. their stregnth increases as the mass and number of electrons in a molecule increases. act over large surrounding surface areas. |
What is a dipole-dipole interaction? | the interraction between the positive end of a dipole of one molecule and the negative end of a nother dipole in the same or different molecule (involves two or more molecules) |
What is the difference between London Dispersion Force and Dipole-Dipole? | LDF works inside a molecule or atom and DD works outside |
what is surface tension? | the layer on the surface of a liquid produced by an uneven intermolecular attraction at its surface |
What is surface tension related to? | intermolecular attraction between its molecules |
What is neat about surface tension? | its creates a layer that is hard to penetrate |
What can happen to a liquid in an open container? | if molecules move slowly (in an open container), it does not break apart from the bonds of a liquid. If the molecules are moving rapidly and upwards, it escapes from the liquid and becomes a gas. This is evaporation. |
What happens to a liquid in a closed container? | molecules in a gaseous state can not fuse away. They will eventually come to *equilibrium*. |
What is vapor pressure? | the pressure of a gas in equilibrium with its liquid form in a closed container |
as the temperature of a liquid increases... | average KE of its molecules increase and the easier it becomes for its molecules to turn from a liquid to a gaseous state. |
As the temperature of a liquid increase its vapor pressure continues to increase until it equals its atmospheric pressure. What is so important about this? | this is the cause of liquid boiling |
The molecules that evaporate from a liquid surface are those that have a higher _____ ________. Those molecules that are left behind have ______ ___________ | kinetic energy, lower kinetic energy |
Because the temperature of a sample is proportional to the anerage kinetic energy of its molecules, the temp of a liquid _______ as a result of ________. | drops, evaporation |
Boiling point | the temperature at which the vapor pressure of a liquid is equal to the atmospheric pressure |
normal boiling point | the temperature at which a liquid boils under a pressure of 1 atm. |
The boiling point of covalent compounds depends on what three factors? | intermolecular forces- strongerthe) number of sites for intermolecular interavtions - greater surface area, harder to boil 3.) Molecular shape |
How does a liquid turn into a solid? | molecules come closer together and attractive forces between them become so strong that random motion stops |
crystallization | formation of a solid from a liquid |
true or false: some compounds have more than one type of solid state | true |
true or false: only after all the liquid water has changed to a gaseous state does the temperature of the sample rise above 100 degrees celcius | true |
heat of fusion | the heat necessary to melt 1.0 g 1 degree celcius of any solid |
specific heat | 1 cal/g * degree celcius |
heat of vaporization | the amount of heat necessary to vaporize 1.0 g of a liquid at its normal boiling point |
true of false: these phase changes are reversable | true |
sublimation | a transition of a solid state directly into a vapor state |