Term
| Define "intermolecular forces" |
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Definition
| an attraction between two or more molecules in a substance |
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Term
If a liquid were to evaporate quickly, is it...
Polar or NonPolar? Is its' intermolecular force weak or strong? |
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Definition
Nonpolar, because the atoms break apart quickly
Weak |
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Term
If a liquid were to evaporate slowly, is it...
Polar or NonPolar? Is its' intermolecular force weak or strong? |
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Definition
Polar, it's atoms are strong,
STRONG |
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Term
| Strong intermolecular forces give a substance a _______ melting point |
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Definition
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Term
| weak intermolecular forces make a liquid _______ to evaporate |
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Definition
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Term
| A substance with nonpolar bonds is probably a _____ |
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Definition
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Term
| Why are gases easily compressable? |
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Definition
| The molecules in a gas are far apart yet have a high kinetic energy, meaning they also move around a lot, so they are compressed easily because from their constant motion and distance from one another the space in between them can be taken easily |
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Term
| Why do solids have a definite shape? |
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Definition
| Because all of the molecules are tightly packed from their strong attraction to one another |
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Term
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Definition
| The molecules collide because of the weak attraction between one another, so the molecules spread out once they collide |
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Term
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Definition
| The particles move freely and therefore collide. From the frequent collisions, the gas particles spread out |
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Term
Give the name for each state change...
solid to liquid:
liquid to solid:
liquid to gas:
gas to liquid:
solid to gas: |
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Definition
solid to liquid: melting
liquid to solid: freezing
liquid to gas: evaporation
gas to liquid: condensation
solid to gas: sublimation |
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Term
| What is the definition for boiling point? |
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Definition
| The temp. where a liquid's vapor pressure equals the external pressure |
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Term
| What is the definition for evaporation? |
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Definition
| The vaporization of a liquid at the surface on a liquid |
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Term
| What is the definition for vapor pressure? |
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Definition
| The pressure exerted by a vapor in equilibrium with the solid or liquid phase of the same substance. Also, the partial pressure of the substance in the atmosphere above the solid or the liquid. |
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Term
| What is the definition for temperature? |
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Definition
| The average kinetic energy of a group of molecules |
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Term
| What is the definition for the absolute zero value? |
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Definition
| All atoms are literally frozen |
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Term
| Explain why the arrangement of ions in table salt is the way it is |
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Definition
| Opposites attract. The positive force of Na attracts to the chlorine in all directions, making it a solid cluster shape |
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Term
| As temp. goes up, the kinetic energy goes ___ |
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Definition
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Term
| Why is evaporation a cooling process? (Think of sweat!) |
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Definition
| The heat from your body causes the water to evaporate and hence heat energy is transferred from the boy to water resulting in cooling of the body. |
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Term
| At temperature goes up, the vapor pressure goes ___ |
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Definition
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Term
| The higher the temperature, the ______ the boiling point |
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Definition
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Term
On a phase diagram:
What does the line between liquid and gas represent?
the line between solid and liquid?
How could you change a liquid into a vapor without changing the temperature? |
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Definition
evaporation/condensation
melting/freezing
sublimation |
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Term
| On a heating or cooling curve, why does the temperature remain constant for a while? |
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Definition
A phase change is occuring.
In a heating curve, as the temperature increases, kinetic energy increases until it reaches the boiling point, wherein there is no increase in potential energy but a rise in potential energy, making the graph plateau.
In a cooling curve, the solid and liquid have the same kinetic energy as it decreases, yet at the melting point, liquid molecule have more potential energy than the solid, making the graph plateau |
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Term
Identify each as endothermic or exothermic:
Melting:
Condensation:
Boiling:
Sublimation:
Freezing:
Evaporation: |
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Definition
Melting: endothermic
Condensation: exothermic
Boiling: endothermic
Sublimation: endothermic
Freezing: exothermic
Evaporation: endothermic |
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Term
| The melting/freezing point of water is... |
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Definition
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