Boiling cold water In a Vacuum Chamber
Summary
TLDRIn this video, a demonstration showcases the process of boiling water at room temperature using a vacuum chamber. By reducing the atmospheric pressure, the presenter successfully lowers the boiling point of water, making it boil at around 15°C. The experiment also highlights how the temperature of the water drops as it boils, demonstrating the endothermic nature of evaporation. The video provides a clear explanation of the relationship between pressure, temperature, and boiling, making it an informative experiment in thermodynamics.
Takeaways
- 🔬 The experiment demonstrates boiling water at room temperature by reducing atmospheric pressure.
- 🧪 Avogadro's law is mentioned, which relates the volume and number of gas particles, affecting pressure.
- 🌡 A thermometer is used to show the temperature of the water, starting at around 23 degrees Celsius.
- 💧 The water is initially evaporating at a low rate due to some molecules having enough energy to overcome intermolecular forces.
- 🚫 The vacuum pump is used to remove gas molecules from the chamber, lowering the pressure above the liquid.
- 🌀 Boiling occurs when the vapor pressure equals the atmospheric pressure, allowing gas molecules to escape.
- 📉 As the pressure is lowered, the water's boiling point decreases, and it begins to boil at lower temperatures.
- 🤔 The temperature of the water actually drops during the process, indicating an endothermic process where heat is absorbed.
- ❄️ The experiment shows water boiling at 15 degrees Celsius, challenging the traditional boiling point.
- 🔄 After boiling, the pressure is allowed to return, and the temperature of the water is observed to have decreased significantly.
- ❄️ The energy for boiling comes from the water itself, causing the temperature to drop as the fastest-moving molecules escape.
Q & A
What is the main purpose of the demonstration in the script?
-The main purpose of the demonstration is to show that water can be made to boil at room temperature by lowering the atmospheric pressure.
What is a vacuum chamber and how is it used in this experiment?
-A vacuum chamber is a container from which air has been removed to create a low-pressure environment. In this experiment, it is used to lower the pressure above the liquid water to facilitate boiling at a reduced temperature.
What is Avogadro's law and how does it relate to the experiment?
-Avogadro's law states that the volume of a gas is inversely proportional to the pressure when the temperature is held constant. In the experiment, lowering the pressure above the water causes the volume of the gas above it to increase, leading to boiling at a lower temperature.
Why does the water start to boil at a lower temperature when the pressure is reduced?
-The water boils at a lower temperature because the reduced atmospheric pressure allows the vapor pressure of the water to equal the external pressure at a lower temperature, which is the condition for boiling.
What is the significance of the thermometer in the experiment?
-The thermometer is used to measure the temperature of the water. It shows the temperature at which the water starts to boil as the pressure is reduced.
What is the relationship between the atmospheric pressure and the boiling point of water?
-The boiling point of water is directly related to the atmospheric pressure. Higher pressure requires a higher temperature for water to boil, while lower pressure allows water to boil at a lower temperature.
Why does the temperature of the water decrease during the experiment?
-The temperature decreases because the boiling process is endothermic, meaning it absorbs heat. As the water molecules gain enough energy to escape into the gas phase, they take energy away from the remaining water, causing its temperature to drop.
What happens when the vacuum pump is turned off and the pressure is allowed back in?
-When the pressure is allowed back in, the water stops boiling and the temperature of the system may stabilize or change depending on the new pressure conditions.
What is the significance of the term 'evaporation' in the context of this experiment?
-Evaporation refers to the process where water molecules with enough energy to overcome the attractive forces between them escape into the gas phase. In the experiment, the rate of evaporation increases as the atmospheric pressure is lowered.
What does the experiment demonstrate about the relationship between pressure and phase changes?
-The experiment demonstrates that by lowering the atmospheric pressure, the phase change from liquid to gas (boiling) can occur at lower temperatures, showing that pressure plays a crucial role in phase transitions.
What is the final temperature of the water after the experiment, and what does this indicate?
-The final temperature of the water is around 14 degrees Celsius. This indicates the amount of energy the water lost during the endothermic process of boiling at reduced pressure.
Outlines
🔬 Boiling Water at Room Temperature
This paragraph describes an experiment where water in a beaker with a thermometer is placed in a vacuum chamber connected to a pump. The purpose is to demonstrate Avogadro's law and the effect of pressure on boiling. The presenter explains that by reducing the atmospheric pressure, the boiling point of water can be lowered, allowing it to boil at room temperature (around 23 degrees Celsius). The process involves the evaporation of water molecules with enough energy to overcome intermolecular forces. As the pressure is lowered, the rate of evaporation increases, and eventually, the water boils at a lower temperature than normal. The experiment also notes a decrease in temperature during the process, indicating that boiling is an endothermic process where the environment gets colder due to the energy required for the phase change.
🌡️ Temperature Change During Boiling
In this paragraph, the focus is on the temperature change observed during the boiling process. Initially, the water's temperature was around 23 degrees Celsius, but as the water boiled at reduced pressure, the temperature dropped to 14 degrees Celsius. This significant temperature drop illustrates the energy loss due to evaporation, emphasizing that boiling is an endothermic process. The summary also mentions the experiment's conclusion, where the water boiled at an even lower temperature of 15 degrees Celsius, and the subsequent reintroduction of atmospheric pressure to observe any changes. The paragraph concludes with a reflection on the energy dynamics of the process, noting that the fastest-moving molecules are the ones leaving due to the lower pressure.
Mindmap
Keywords
💡Water
💡Beaker
💡Thermometer
💡Vacuum Chamber
💡Vacuum Pump
💡Avogadro's Law
💡Pressure
💡Evaporation
💡Boiling Point
💡Endothermic Process
💡Vapor Pressure
Highlights
Demonstration of boiling water at room temperature by lowering atmospheric pressure.
Explanation of Avogadro's law relating to pressure and volume with a decrease in gas particles.
Setup of a vacuum chamber to remove air molecules and lower pressure.
Evaporation of water at room temperature due to molecules with enough energy to overcome intermolecular forces.
Attempt to achieve boiling without increasing temperature by manipulating atmospheric pressure.
Boiling point is the equilibrium between gas molecules escaping and atmospheric pressure.
Observation of water evaporating without boiling due to high atmospheric pressure.
Activation of the vacuum pump to reduce pressure and initiate the boiling process.
Denting of the glass chamber as a visual indicator of gas molecules being removed.
Evaporation rate increase as atmospheric pressure decreases.
Unexpected temperature drop during the boiling process.
Boiling observed at 21 degrees Celsius due to reduced atmospheric pressure.
Theoretical explanation of Le Chatelier's principle and its application in this experiment.
Visual confirmation of water boiling at 15 degrees Celsius.
Restoration of atmospheric pressure to observe the system's reaction.
Post-experiment temperature reading of 14 degrees Celsius, indicating energy loss during boiling.
Discussion on the endothermic nature of the boiling process and its environmental impact.
Transcripts
in this demonstration I am taking water
that's in a beaker and it has a
thermometer in it and it's going to be
placed in something called a vacuum
chamber so as I pan back out here you're
gonna see that I have I connected it
connected that apparatus to a vacuum
pump which is going to pump out the air
molecules Avogadro's law states pressure
or at least the volume decreases with
number of particles but as we lower the
number of gas particles in the container
I'm gonna lower the pressure so what I'm
trying to do is and I put the top back
on and seal it here what I'm gonna try
to do is take out the gas molecule so
I'm gonna try to lower the pressure
above the liquid we know the liquid
right now is evaporating because it does
have molecules that have enough energy
to overcome the attractive forces
between them and we know it's
evaporating but at a low rate and we're
trying to get boiling here we're trying
to boil water at room temperature you
can read the thermometer is about 23 or
so hard to read through the the glass
chamber but it's about 23 and we're
gonna try to boil this water at room
temperature about 23 degrees Celsius by
lowering the atmospheric pressure that's
all I'm trying to do here because we
know that boiling is when the
atmospheric pressure upward which is the
gas molecules escaping into the gas
phase equal the atmospheric pressure
pushing down when those two forces are
equal we get boiling so you say the
blunt point of water it can be any
temperature so I'm trying to prove that
so let me turn on the vacuum pump lower
the pressure and right now this water is
evaporating it is going from a gas
liquid phase to a gas phase right now we
don't see it because you can't see steam
but it's not boiling because the
atmospheric pressure is too large so
we're gonna lower the atmospheric
pressure right now
and I'm pointing out the dents mark is
and once I drive out all the gas
molecules they'll be less molecules to
collide with the surface less force
pushing down the surface and I said
achieve a maximum rate of evaporation
that wins you can choose seat starting
and happy now and there's our woman now
wants to take careful look at the
temperature of the system it's actually
falling a little bit you need to say
well why is the temperature dropping
we're boiling at 22 degrees Celsius 21
degrees Celsius
very interesting the properly boil at 1
degree Celsius because for Lea's limit
at least that's your equal to vapor
pressure and at 21 degrees Celsius
introducing a lot of pressure
you've got boiling you look carefully
though the temperature is dropping the
temperatures getting under the water is
getting cooler as important the
operation of only the n-doped in the
process we're not applying any be here
what where's the energy coming from to
make this is losing the molecules that
are moving the fastest are leaving as
dennis molecules because of the lower
courts as well as
okay
[Music]
[Music]
this man alright and we made water boil
at 15 degrees Celsius what I'm gonna do
now is I'm going to let the pressure
back in and see what happens okay I
don't think I saw any freezing but let's
see if we can read that thermometer any
better okay so the energy that was used
to boil okay
is being used and then he got pretty
cold so if you look at our thermometer
we're still about 14 degrees Celsius so
we were at 23 and we're down to 14 that
showed us how much energy the water lost
to the evaporation member evaporation
boiling is an endothermic process the
environment gets colder
Weitere ähnliche Videos ansehen
Simplest Way To Understand Boiling Point Elevation & Vapor Pressure Depression
LINDE LIQUEFACTION PROCESS
Heating Curves Temperature Energy Graphs | GCSE Physics
Simple Distillation | #aumsum #kids #science #education #children
NECT Gr 10 Heating and Cooling Curve of Water
GCSE Physics - Specific Latent Heat #29
5.0 / 5 (0 votes)