States of Matter and Changes of State
Name
boiling
Assume that the images above show the same substance, but in three
different states.
_____________________________1.
In which state is the substance the most
dense?
_____________________________2.
In which state is it the least dense?
_____________________________3.
In which state do the particles of the
substance have the most energy?
_____________________________4.
In which state do the particles of the
substance have the least energy?
_____________________________5.
What happens to the volume of a substance
when it changes from gas to liquid to solid?
_____________________________6.
What happens to the density of a substance
when it changes from gas to liquid to solid?
_____________________________7. Assuming that no gas escapes, in which state
would the substance have the least mass?
15. You are keeping sodas cold in a cooler using dry ice, which isn’t really ice at all,
but solid carbon dioxide. Your little brother asks you why there is no water in the
bottom of the cooler from the melting ice. What do you tell him?
8. Which of the following requires the most energy:
a. melting water from solid to liquid
b. heating liquid water to 100 degrees Celsius
c. boiling water from liquid to gas
In the graph above, it shows energy (in units called Joules) being
added continuously to water. List three (3) different changes this
energy causes in the water.
9.
10.
11.
12. What is the boiling point of water? ____________________________________
13. What is the condensation point of water? _____________________________
I4. In order to get something to freeze solid, you would need to
remove energy until the temperature reached its _______________________.
16. After you explain to your brother what dry ice is, he says, “Oh yeah! I can see the
CO2 gas swirling around the dry ice.” You suppress a chuckle and explain to him that
it is really water vapor. He says, “Hey, you just told me that the dry ice wasn’t even
water.“ Explain where the water came from and why he can see it.
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SPOILER ALERT!! If you can explain numbers 16 and 17, you can
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use those ideas to help you explain Dippy!!
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17. Explain why sweating causes you to feel cool.
Positive Crankcase Ventilation System
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CHALLENGE….
If you have time, read on and see if you can answer any of the
following questions. You will need extra paper for your answers if
you do.
Vapor lock is a problem that mostly affects gasoline-fueled internal
combustion engines, like the one in most cars and trucks.It occurs
when the liquid fuel changes state from liquid to gas while still in the
fuel delivery system. This disrupts the operation of the fuel pump,
causing loss of feed pressure to the carburetor or fuel injection
system. This results in brief loss of power or complete stalling,
which means the engine quits running. Restarting the engine from
this state may be difficult.The fuel can vaporize due to being heated
by the engine, by the local climate or due to a lower pressure at
high altitude.
18. .Go on line and see if you can explain why vapor lock happens
AND
19. find a solution for an engine that has vapor lock
AND
20. explain why that solution actually works.
See if you can explain any of the following;
21. Why do hot air balloons rise?
22. Why does a glass bowl crack when it is taken from the oven and
placed on a cold, tile counter?
23. Why should you avoid filling your tires more than the
recommended amount even if lots more air will fit?
24. Why is there moisture all over the outside of my drinking glass?
The introduction of positive crankcase ventilation (PCV) in the 1960’s
marked the beginning of evaporative emission control systems in the
automobile. The initial purpose of the PCV system was to capture
crankcase vapors and prevent them from being vented into the atmosphere
through the road draft tubes in use at the time.
Parts of the System (A, B, C)
C. is the PCV valve that collects fuel vapors (gases)
B. is the manifold vacuum that sucks the PCV gases out of
the engine at low revs.
A. is the Breather tube that allows fresh air to replace the
PCV gases when they are evacuated by the manifold
vacuum.
Since gasoline fuel is a liquid, but it has a boiling point of
about 40o Celsius (which is about 104o F), it will already
turn to a gas (vapor) at a much lower temperature than
liquids like water(100oC) or motor oil (about 300 oC). Why
do you think it is important for us to have PCV systems in
our cars?