Unit 7: Lesson 2 Intermolecular Forces II
________ forces in a capillary action are intermolecular attractions between the liquid and the glass.
Adhesive
________ ___ _____________ is the heat absorbed when water is boiling
Enthalpy of vaporization, ΔH(vaporization)
In boiling, __________ occurs ___________ the liquid when the vapor pressure equals the atmospheric pressure. As a bubble forms, more water _______ into the bubble. The _______ pressure inside the bubble pushes boiling water to the side.
Evaporation inside evaporates vapor
What does Enthalpy of vaporization and Enthalpy of fusion look like on a temperature vs heat graph?
Flat lines
How to calculate sublimation enthalpy?
Sum of fusion enthalpy and vaporization enthalpy
Water rises up a capillary because _________ forces and _______ forces are at work.
adhesive cohesive
Surface tension The particles within a liquid experience forces or attraction in _______ directions. The particles on the surface of a liquid are attracted to particles _______ and ______ them. On a freshly waxed car, there is ________ ______ intermolecular attraction between the polar water molecules and the non-polar wax.
all beside underneath almost no
Temperature is the measure of the _________ ________ ________ of atoms and molecules in a system.
average kinetic energy
Grey area Dissolving a salt in water involves ________ ionic bonds and _________ ion-dipole interactions
breaking creating
Surface tension The particles within a liquid experience forces or attraction in all directions, so the force vectors ______, and there is ______ ______ attraction.
cancel no net
If a small-diameter glass tube (________) is placed in water, water ______ up the tube.
capillary rises
Chemical processes Involve the breaking and/or formation of ______ ______
chemical bonds
________ forces in a capillary action are intermolecular attractions between molecules in the liquid.
cohesive
Energy must be added to a liquid in order to __________ its surface tension and __________ its surface area. Surface tension _____ as temperature _________.
decrease increase decreases increases
When at a higher elevation, atmospheric pressure and boiling point ________ .
decreases
Viscosity __________ as the temperature increases. Particles at a higher temperature have more _______ to ________ the forces of attraction.
decreases KE counteract
Boiling point __________ as elevation increases, although boiling point changes food still needs to be cooked at a ___________ temperature.
decreases specific
Polar molecules in a solid state line up in a regular pattern to form strong __________-_________ attractions that maintain the ________ of the structure. _________ _________ forces also exist in solids.
dipole dipole organization London dispersion
Cooking is an ___________ chemical reaction.
endothermic
ΔH+ is
endothermic
The process is __________ as it gets closer to the _______ phase because it needs energy to break the intermolecular attractions.
endothermic gas
In a closed container, a liquid will reach a state of equilibrium where: rate of evaporation = rate of condensation. If you add heat, the equilibrium will shift in the _______________ direction to produce ________ gas.
endothermic more (products)
The heat required to liquify 1 mole of a substance is its _________ _________ _________ , _________. For water, this occurs at 0 degrees celsius.
enthalpy of fusion ΔH(fus)
Sublimation is when solids can ______ and have a _________.
evaporate vapor pressure
In a closed container, a liquid will reach a state of equilbrium where: rate of _____________ = rate of __________
evaporation condensation
ΔH- is
exothermic
The process is __________ as it gets closer to the _______ phase because it releases energy to form the intermolecular attractions.
exothermic solid
Plastics are generally __________ solids or __________ liquids. _______________ plastics increases flexibility, and allows them to be molded. Properties of synthetic materials can be __________ by manipulating their structure.
flexible viscous Heating modified
Physical processes involve changes in weak ______ ______
intermolecular interactions
Heat fusion is defined as the heat gained as 1 mol of solid _______.
liquefies
During supercooling the substance remains in the _______ phase after the temperature has dropped below the -________ temperature.
liquid freezing
The vapor pressures of ionic solids are very ________ because of the strong coulombic interactions between cations and anions.
low
Vapor pressures of solids are typically _________. If they have ______ vapor pressures, it's because they have relatively ______ intermolecular forces.
low high weak
Partial pressure of a certain gas is determined by the relative number (or ______ _______) of those particles that are present in a gaseous system...not the type of _______ __________.
mole fraction gas particle
A _________ __________ on surface molecules causes some to accelerate into the ______________ of the liquid.
net force center
In a gas, we generally assume that particles have _____ intermolecular forces of attraction. In a liquid, attractive forces are still quite _______.
no large
Enthalpy of vaporization and Enthalpy of fusion, energy is used to overcome intermolecular forces _____ _______ Kinetic energy.
not increase
Heat fusion is defined as the heat gained as 1 mol of solid liquefies. The energy released when 1 mol of a pure liquid solidifies is equal in magnitude but _________ in sign.
opposite
If a small-diameter glass tube (capillary) is placed in mercury, the _____ of water occurs. The adhesive forces between Hg and the glass are _______ than the cohesive forces between the Hg atoms.
opposite weaker
A system becomes more stable when its PE is _________. The ______ PE is achieved with the _________ possible surface area (a spherical shape).
reduced lowest smallest
In a solid, molecules are held close together in a ________ ______ by intermolecular forces.
regular pattern
Surface tension is the _________ of a liquid to spread out and ________ its surface area. Ex:
resistance increase Water beading on a freshly waxed car.
Viscosity is the measure of a liquid's _______ to flow. Viscosity increases as the strength of intermolecular forces _______.
resistance increases increases
As a general rule, the boiling point __________ as the amount of energy required to push liquids into the gas phase _______. This reflects the type of ___________ forces that the substance exhibits and its ______.
rises increases intermolecular size
As you continue to add heat to a solid that is liquefying, it stays at the ______ temperature until all of it has ________. The internal energy of the system is _____________, but the temperature is not, because the energy is being used to _________ the attractions from intermolecular forces.
same liquefied increasing sever/stretch
Surface tension A ___________ shape has the smallest surface area.
spherical
The vapor pressure on the surface of a liquid depends on the __________ of its _________ forces. A molecule restrained by strong intermolecular forces requires _________ energy to break free from its liquid state. When a system requires ________ energy to cause its molecules to enter the gas phase, it will also require _______ energy to cause its vapor pressure to equal the atmospheric pressure.
strength intermolecular more more more
In a liquid the intermolecular forces of attraction exist. These aren't as ________ as the intermolecular forces of solids.
strong
The Adhesive forces in a capillary action are _________ than the cohesive forces. The ______ forces pull the water up the walls of the glass tube, and the _________ forces pull up the liquid. Resulting in a small ________.
stronger adhesive cohesive meniscus
Liquids with __________ intermolecular attractions have larger differences in potential energy between interior and surface molecules, and ________ surface tensions.
stronger greater
As ionic bonds are much _______ than intermolecular forces, the ΔH(fus) values for ionic compounds are very _______. That's why ionic bonds have ________ melting points.
stronger large higher
The intermolecular forces in the liquid phase are much ________ than they are in the gas phase. Ideally, gas particles experience ______ intermolecular forces whatsoever and if they do, it's ___________.
stronger no negligable
Some liquids ________ before they solidify.
supercool
At the bottom of the ________ curve, _______ crystals form. This causes the temperature of the system to _______ dramatically, as heat is released by the solvent particles during the process of solidification.
supercooling solid increase
Evaporation is when liquid turns to gas at the ___________ of a liquid and when __________ the temperature of the boiling point.
surface below
Remember that ___________ is the only stress that changes the value of the equilibrium constant, K(eq).
temperature
Vaporization is when liquid turns to gas at certain _______ and _______.
temperature pressure
A liquid boils when its ______ pressure equals the _________ pressure.
vapor atmospheric
In a closed container, the __________ __________ is the partial pressure of the gas on the surface of its liquid when the system is at equilibrium.
vapor pressure
When a syst reaches its boiling point , it stays at the same temperature until all of the liquid has _____________. This heat is instead used to _____________ attractions from intermolecular forces.
vaporized severe
The bubbles in boiling water has _______________ _______________ not _______________ _______________.
water vapor air bubbles
Intermolecular forces of attraction are _______ in the liquid phase than they are in the solid phase. Energy must be _______ in order to reduce these restraints.
weaker absorbed