General
Convert 345 K to Celsius.
71.8
Which phase change is depicted below.
CO2 (s) -> CO2 (g)
Sublimation
Bonus Points - What is the reverse process called?
Solid - liquid - gas
A heating curve is ______ (endo/exo) and a cooling curve is _______ (endo/exo)
Endothermic; exothermic
How does evaporation rate connect to IMFs of a substance?
The quicker the evaporation rate, the weaker the IMFs
What is entropy?
The amount of disorder in a system.
Bonus- Give an example of entropy increasing during a phase change
List the exothermic phase changes.
Condensing, Deposition, Freezing
Bonus - name the endothermic phase changes.
Describe the difference between endothermic and exothermic.
Endo - absorbs heat(energy)
Exo - release heat(energy)
Where on a heating curve does KE increase?
Areas that increase; where one state of matter is present
Bonus: Where on a cooling curve does PE decrease?
What temperature will water boil at 110kPa?
105 C
How is the average kinetic energy of the particles of a substance related to the temperature of that substance?
Higher temp = greater avg. KE
Explain the difference between evaporation and boiling.
Evaporation - high energy particles on surface of liquid leave system
Boiling - high energy particles throughout the liquid leave system
Write an equation depicting an exothermic reaction.
During a segment on a cooling curve with two phases present, what happens to the KE and PE?
KE - stays the same
PE - Decreases
At what pressure will propanone boil at 20C
25 kPa
Draw the phase of matter Tin is in at 1000 K.
Liquid Phase
bonus - what phase of matter is iodine in at 321 K ?
Write a chemical equation depicting the sublimation of Iodine.
I2(s) -> I2(g)
Which sample has particles with the highest average kinetic energy?
a. H2O (l) @ 55 C
b. Br2 @ 75 C
NaCl (aq) @ 30 C
Mg (s) @ 17 C
b. Br2 @ 75 C
Bonus - which sample has the lowest avg. KE.
Describe what happens to the IMFs in a substance as it goes through a heating curve.
Gradually weaken as it moves to a higher energy state
What is vapor pressure?
The pressure exerted by the gas in equilibrium with a solid or liquid in a closed container at a given temperature
Convert 4560 Pa to atm.
0.04 atm
Name three properties for each state of matter.
Solid - crystalline, fixed, vibrate in place, strong IMFs
Liquid- definite volume, flows, no definite shape, medium IMFs
Gas - No def volume or shape, particles move fast, little IMFs
Bonds breaking is a ____________ rxn
Bonds forming is a _____________ rxn.
Breaking- endothermic
Forming- exothermic
Correctly label a heating curve with the following terms:
-Solid, liquid, gas
-melting point and boiling point
-areas where more than one phase is present
-Kinetic energy increase and potential energy increase
see heating curve
Explain why propanone has the highest vapor pressure at room temperature.
Relatively weak intermolecular forces which allows its molecules to easily escape from the liquid phase and transition into the gas phase compared to other similar compounds with stronger intermolecular forces