Endothermic reaction: very, VERY cool.
Summary
TLDRIn this experiment, the presenter combines barium hydroxide with ammonium chloride to demonstrate an endothermic reaction. As they mix the chemicals, the reaction absorbs heat, becoming cold enough to freeze water on a wooden block. The process also releases ammonia, producing a pungent smell. The presenter notes the dramatic temperature drop, which is measured to be below zero, and observes ice crystals forming. Despite the cold, the reaction remains subtle but visually interesting, engaging viewers with its scientific and sensory effects.
Takeaways
- đ§Ș The speaker is mixing barium hydroxide and ammonium chloride to demonstrate an endothermic reaction.
- đ„¶ The reaction is expected to absorb heat, making it endothermic, rather than releasing heat as in an exothermic reaction.
- đ§ The speaker wets a wooden block to show how cold the reaction will become, indicating the heat being absorbed from the environment.
- đ§ The barium hydroxide and ammonium chloride mix together, transitioning from solid powders to a liquid state.
- đ· The reaction releases ammonia gas, which the speaker notices by the strong, unpleasant smell.
- âïž As the reaction progresses, the mixture gets very cold, cold enough to freeze the water onto the bottom of the wooden block.
- đ The temperature drops quickly, reaching below zero degrees Celsius, as observed using a thermometer calibrated to minus 10°C.
- đĄïž The thermometer reads minus 5°C at one point, confirming that significant heat is being absorbed by the reaction.
- âïž Ice crystals start forming on the sides due to the low temperature.
- đ« The speaker warns against touching the mixture, as it might freeze skin if touched.
Q & A
What are the two chemicals mentioned in the experiment?
-The two chemicals mentioned are barium hydroxide and ammonium chloride.
What type of reaction is being demonstrated in the experiment?
-The experiment is demonstrating an endothermic reaction.
Why does the speaker mention a wooden block being made wet?
-The speaker wets the wooden block to show how much heat the reaction is taking in by freezing the water onto the block.
What product is formed from the reaction between barium hydroxide and ammonium chloride?
-One of the products formed in the reaction is water, which causes the mixture to change consistency and become more liquid.
What gas is released during the reaction, and why does the speaker comment on its smell?
-Ammonia gas is released during the reaction, and the speaker comments on its unpleasant, tangy smell.
What temperature does the reaction reach, according to the speaker?
-The reaction drops below freezing, reaching around -5°C, as indicated by the thermometer.
What physical effect does the endothermic reaction have on the water at the base of the beaker?
-The reaction absorbs so much heat that the water freezes and sticks to the bottom of the beaker.
Why does the speaker say that the reaction is âpretty coolâ?
-The speaker is impressed by the fact that the reaction absorbed enough heat to freeze the water at the bottom of the beaker, making the reaction visually and scientifically interesting.
What safety precautions does the speaker mention during the experiment?
-The speaker mentions using hand sanitizer after chopping hearts earlier, indicating awareness of cleanliness and safety during experiments.
Why does the speaker express concern about ammonia during the experiment?
-The speaker forgot that ammonia would be released, accidentally inhaling it, and commented on its strong, unpleasant smell.
Outlines
đŹ Mixing Barium Hydroxide and Ammonium Chloride for an Endothermic Reaction
The presenter begins by introducing barium hydroxide, which will be mixed with ammonium chloride to observe an endothermic reaction. They explain that they will use a beaker instead of another tool because it is more practical. The goal of the demonstration is to show how the reaction absorbs heat from its surroundings.
đ§Œ Discussing Hand Sanitizer and the Setup for the Experiment
The presenter briefly digresses to mention hand sanitizer on their desk, explaining that it is needed after handling hearts, possibly in a previous experiment. They prepare to demonstrate the endothermic reaction by wetting a wooden block to show how much heat the reaction absorbs from the surroundings.
âïž Mixing the Chemicals and Observing the Reaction
The chemicals (barium hydroxide and ammonium chloride) are mixed together, and the presenter discusses the reaction, hoping it will be endothermic and not exothermic. As they combine the substances, the consistency changes, producing water, and the solid powders begin turning into liquid.
đ· Ammonia Release and Observing the Cold Reaction
The presenter comments on the release of ammonia from the reaction, which has a strong and unpleasant smell. They accidentally inhale some of the fumes, explaining that the smell is ammonia, which is often associated with the odor of urine. The reaction is now making the mixture cold.
âïž Freezing Water with the Endothermic Reaction
As the reaction progresses, the presenter notices the temperature dropping significantly, to the point where the water placed on the wooden block is frozen. The reaction has absorbed so much energy from its surroundings that it causes the water to freeze. The presenter checks the temperature, which drops to below freezing.
đĄïž Measuring Temperature and Further Cooling
The presenter checks the temperature using a thermometer, confirming that it has dropped to below zero. The thermometer reads approximately -5°C and continues to drop. Ice crystals begin to form on the sides of the container, and the presenter notes that if touched, the cold surface could freeze their fingers.
Mindmap
Keywords
đĄBarium Hydroxide
đĄAmmonium Chloride
đĄEndothermic Reaction
đĄExothermic Reaction
đĄAmmonia
đĄReaction Products
đĄFreezing
đĄThermometer
đĄAmmonium Chloride Smell
đĄEnergy Absorption
Highlights
Introduction of barium hydroxide and ammonium chloride for an endothermic reaction.
The experiment involves mixing barium hydroxide and ammonium chloride to observe the temperature drop.
The demonstrator explains that the reaction should be endothermic, subtly taking in heat instead of releasing it.
Observation that one of the products of the reaction is water, leading to the mixture turning from solid to liquid.
Ammonium chloride gives off ammonia, creating a distinctive smell in the process.
The reaction is described as generating a noticeable cooling effect, making the surroundings colder.
The demonstrator intentionally wets a wooden block to showcase how cold the reaction gets by trying to freeze water on the surface.
The experiment progresses and successfully freezes the water to the wooden block, indicating the significant temperature drop.
The demonstrator checks the temperature with a thermometer calibrated to minus 10°C, which drops below zero, showing the reaction's intensity.
Observation that ice crystals are forming on the side, confirming the cooling effect of the reaction.
Ammonia produced by the reaction creates a pungent odor, which is noticeable to the demonstrator.
The demonstrator humorously notes the danger of freezing fingers to the frozen surface, highlighting the reaction's cooling strength.
The physical consistency of the mixture changes from solid to liquid as water is produced in the reaction.
The demonstrator points out how the reaction absorbs heat from the environment, effectively demonstrating the principles of an endothermic reaction.
Ice begins to form on the wooden block, further illustrating the extent to which the reaction pulls energy from its surroundings.
Transcripts
what I have is some barium hydroxide
okay and I'm going to put this into the
in fact you know what I'm going to do
this in one of the beakers not that
thing because it's ridiculous bar
hydroxide and I've got some ammonium
chloride now what I'm going to do is mix
these together and hopefully we should
see a endothermic
reaction yes this with the hand stuff
what hand stuff the hand sanitizer oh it
just lives on my desk I was chopping up
Hearts earlier and yeah I need to be not
covered in blood so what I'm goingon to
do to show how exothermic this is how
much heat this is taking in so I'm going
to make this wooden block wet okay now
um you will see why I've done that in a
second so I'm going to mix these two
things together and carefully
um bit mix these two things together
well hopefully not because if it's
blowing up and giving out huge amounts
of energy like that that would be what
Ty reaction exothermic now we want to
see endothermic so it's going to be a
little bit more subtle so I mix the B
hydroxide and ammonium chloride together
it fre and they should start to react
does it freeze it
well we should soon see so they're
mixing together now can you see how the
consistency of that is changing slightly
it's of clumping together cuz one of the
products it's making is water in this
reaction and you can see actually that's
all gone liquid and it was all just
solid powders it's not milk you wouldn't
want
to okay you put that in
coffee be in problems now one of the
products of this because it's ammonium
chloride is it's giving off ammonia
which smells rather horrible and I
forgot about that which is why I Just
Breath the H in um that sort of horrible
slightly Tangy smell in we is um sort of
ammonia light oh is that what I can
smell yeah that's what you can smell
unless you've wet yourself that is can
smell okay but also actually I'm this is
getting actually very cold as it's going
along okay now hopefully if this is
worked it's getting cold enough well you
know I put water on the base there yeah
fingers
crossed it's frozen the water onto the
Bottom now this reaction has worked so
well so much energy has had to be taken
out of the environment it's got that
water so cold that it's dropped below
freezing and Frozen onto the bottom that
is pretty
cool uh well I Haven got in fact I have
got a thermometer I'm an absolute liar
so I can put that there um then is
dropping down to well we know it's below
what zero so
ume this thermometer is calibrated to
minus 10 it's shot down to
minus5 by about
now um
and it's carrying on going will it
freeze our fingers uh if you heard it on
there yeah it would start to in fact
there's actually ice crystals forming on
the side can I touch cool yeah uh no
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