Double Displacement Reactions
Summary
TLDRThis educational video script details a chemistry experiment exploring double displacement reactions. Six test tubes with salt water (sodium chloride) are exposed to various reactants, including calcium hydroxide, copper sulfate, hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride. The reactions are observed for signs of precipitate, color change, or gas release. The script explains why certain reactions occur, such as the formation of insoluble calcium sulfate from copper sulfate and calcium hydroxide, and the neutralization reaction between hydrochloric acid and sodium hydroxide, forming water and salt. The experiment highlights the conditions necessary for a double displacement reaction to take place.
Takeaways
- π§ͺ The experiment involves testing double displacement reactions between salt water and six different compounds.
- π¬ Salt water, primarily sodium chloride, is mixed with calcium hydroxide, copper sulfate, hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride to observe reactions.
- π No visible reactions were observed initially with the addition of the second reactants to the salt water.
- π Double displacement reactions occur if a gas, solid, or covalent compound like water is formed.
- π« The reactions with calcium hydroxide and sodium chloride did not proceed because both resulting compounds, calcium chloride and sodium hydroxide, are soluble in water.
- π Copper sulfate and sodium hydroxide reacted to form copper hydroxide precipitate and sodium sulfate, with the former being insoluble.
- π§ Hydrochloric acid and calcium hydroxide reacted to form water and calcium chloride, with the former being a covalent compound indicating a reaction.
- π€ The lack of visible reaction with sodium hydroxide and hydrochloric acid was confirmed using phenolphthalein as an indicator, revealing a neutralization reaction.
- 𧩠The experiment demonstrates the concept of solubility and reactivity in chemical reactions, showing that not all compounds will react with each other.
- π Calcium chloride reacted with sodium hydroxide to form calcium hydroxide precipitate, indicating a successful double displacement reaction.
- π The experiment concludes that reactions occurred with copper sulfate and hydrochloric acid, but not with sodium, calcium, or potassium chloride due to the lack of formation of a precipitate, gas, or covalent compound.
Q & A
What is the purpose of adding different reactants to the test tubes containing salt water?
-The purpose is to check for a double displacement reaction among the reactants and salt water.
Which reactants were added to the test tubes containing salt water?
-Calcium hydroxide, copper sulfate, hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride were added.
What was observed in the test tubes after adding the reactants to the salt water?
-No color change, no bubbles indicating gas, and no precipitate at the bottom were observed, suggesting no reaction occurred.
Why did the reaction between sodium chloride and calcium hydroxide not proceed?
-The potential products, calcium chloride and sodium hydroxide, are both water-soluble, providing no reason for the reaction to proceed.
What conditions are necessary for a double displacement reaction to occur?
-A double displacement reaction will occur if a gas is formed, a solid precipitate is formed, or a covalent compound like water is formed.
What happened when copper sulfate was added to the test tubes containing calcium hydroxide?
-A reaction occurred, forming a precipitate of calcium sulfate, which is insoluble in water.
What was the observed reaction when hydrochloric acid was added to calcium hydroxide?
-A reaction occurred, forming calcium chloride, which is water-soluble, and water, a covalent compound.
What is the significance of the reaction between copper sulfate and sodium hydroxide?
-The reaction forms copper hydroxide, which is insoluble and forms a precipitate, and sodium sulfate.
Why was there no visible reaction when hydrochloric acid was added to sodium hydroxide?
-The reaction between hydrochloric acid and sodium hydroxide is a neutralization reaction forming water and sodium chloride, which may not be visibly obvious without an indicator.
How was the neutralization reaction between hydrochloric acid and sodium hydroxide confirmed?
-The reaction was confirmed by using phenolphthalein as an indicator, which turned the solution pink in the presence of the base, sodium hydroxide.
What was the observed reaction when calcium chloride was added to sodium hydroxide?
-A reaction occurred, forming a precipitate of calcium hydroxide, which is insoluble in water.
Why did the addition of potassium chloride to sodium hydroxide not result in a reaction?
-Both potassium chloride and sodium hydroxide are chlorides, so there is no reason for the chloride ions to switch and no reaction occurs.
Outlines
π§ͺ Double Displacement Reactions with Salt Water
This paragraph describes an experiment involving six test tubes filled with salt water to which various reactants are added to test for double displacement reactions. The reactants include calcium hydroxide, copper sulfate, hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride. The experiment shows no visible reaction, indicating that none of these substances react with salt water under the conditions provided. The explanation provided is that a double displacement reaction requires the formation of a gas, solid, or covalent compound like water, which did not occur in these cases.
π¬ Reaction Series with Calcium Hydroxide and Copper Sulfate
In this section, the experimenter adds different reactants to test tubes containing calcium hydroxide and copper sulfate. The addition of copper sulfate to calcium hydroxide results in the formation of calcium sulfate, which is insoluble and forms a 'snotty' precipitate. Hydrochloric acid reacts with calcium hydroxide to form calcium chloride and water, which is a covalent compound, indicating a neutralization reaction. Other reactants like sodium hydroxide, calcium chloride, and potassium chloride show no visible reaction, suggesting that no double displacement occurred due to the lack of formation of a precipitate, gas, or covalent compound.
π Copper Sulfate Activity Series and Reaction Observations
The paragraph details the reactions of copper sulfate with various substances, including hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride. Sodium hydroxide reacts with copper sulfate to form copper hydroxide precipitate and sodium sulfate. Calcium chloride also shows a reaction with copper sulfate, forming a precipitate. However, hydrochloric acid and potassium chloride do not show an immediate reaction. The use of phenolphthalein as an indicator confirms the neutralization reaction between sodium hydroxide and hydrochloric acid, despite the lack of visible change.
π Hydrochloric Acid and Sodium Hydroxide Neutralization
This paragraph focuses on the neutralization reaction between hydrochloric acid and sodium hydroxide, which results in the formation of water and sodium chloride. The experiment shows that calcium chloride reacts with sodium hydroxide to form calcium hydroxide precipitate. Potassium chloride does not react with sodium hydroxide, as both are already bonded to chlorine, and there is no driving force for a reaction. The use of phenolphthalein as an indicator helps to confirm the occurrence of the neutralization reaction, which was not initially visible.
Mindmap
Keywords
π‘Double Displacement Reaction
π‘Reactants
π‘Precipitate
π‘Soluble
π‘Covalent Compound
π‘Indicator
π‘Neutralization Reaction
π‘Insoluble
π‘Sodium Chloride
π‘Activity Series
Highlights
Experiment begins with six test tubes containing salt water and various reactants to check for double displacement reactions.
No visible reaction observed with the addition of calcium hydroxide, copper sulfate, hydrochloric acid, sodium hydroxide, calcium chloride, and potassium chloride to salt water.
Explanation of why no reaction occurred with sodium chloride and the six compounds based on solubility and the criteria for double displacement reactions.
Copper sulfate and calcium hydroxide reaction produces a precipitate, indicating a reaction between the two.
Hydrochloric acid reacts with copper sulfate, forming a precipitate almost immediately, unlike other reactants.
Sodium hydroxide and hydrochloric acid predicted to react in a neutralization reaction, forming water and sodium chloride.
Use of phenolphthalein as an indicator to confirm the neutralization reaction between sodium hydroxide and hydrochloric acid.
Observation of a precipitate forming in the reaction between copper sulfate and sodium hydroxide, indicating the formation of copper hydroxide.
No visible reaction with calcium chloride and copper sulfate initially, but a precipitate is later observed.
No reaction observed between hydrochloric acid and either calcium chloride or potassium chloride due to the lack of driving force.
Demonstration of the difficulty in observing reactions with insoluble calcium hydroxide in water.
Calcium hydroxide and copper sulfate reaction results in calcium sulfate, an insoluble compound that forms a distinct texture.
The importance of covalent compound formation, such as water, in driving double displacement reactions.
No reactions observed with sodium hydroxide, calcium chloride, and potassium chloride in the activity series.
Reaction between sodium hydroxide and calcium chloride, resulting in the formation of calcium hydroxide precipitate.
Final observation of no reaction between calcium chloride and potassium chloride due to both being chlorides.
Summary of the chemical reactions and the conditions necessary for them to occur, emphasizing the role of solubility and the formation of covalent compounds.
Transcripts
okay as you can see here we've got our
salt water so we have about somewhere
between two and three mils of salt water
in each of these six test tubes now
going along with our reaction series
we're going to add our second reactant
to each of these test tubes to check for
a double displacement reaction we've got
calcium hydroxide copper sulfate
hydrochloric acid sodium hydroxide
calcium chloride and potassium chloride
those are the six things that we're
gonna add to these test tubes which all
just contain salt water right now
sodium chloride let's begin we'll start
with our calcium hydroxide this is
barely soluble in water most of it is
settled to the bottom of the beaker so
let's sprinkle some of that it next
we'll do our copper sulfate
next our hydrochloric acid
our sodium hydroxide
calcium chloride
and potassium chloride
okay I'm looking at these test tubes
right now and I see no indication of a
reaction no color change no bubbles to
indicate a gas no precipitate at the
bottom so it appears that none of the
salt water has reacted with these other
compounds
all right so here's our saltwater and we
saw that the saltwater didn't react with
any of the six other compounds what I'm
gonna do now is explain why so in our
first speaker over here I'm sorry our
first test-tube
we've got calcium hydroxide in saltwater
so the sodium chloride could react with
the calcium hydroxide but then we'd have
calcium chloride which is water soluble
and sodium hydroxide which is also
soluble so no reason for that reaction
to go again a double displacement
reaction will only occur if a gas is
formed a solid is formed or a covalent
compound is formed such as water so that
first reaction didn't meet any of those
criterion of those criteria so no
reaction second reaction we have copper
sulfate and in salt water that could
form sodium sulfate and also copper
chloride both of those things are water
soluble so no reaction next one we have
sodium chloride and hydrochloric acid
there's no reason for this reaction to
happen right we just be trading chlorine
for chlorine so why bother same thing
over here we have sodium chloride and
sodium hydroxide both of these compounds
have sodium in them
so why would sodium switch with sodium
and when you wouldn't change anything in
the grand scheme of things
same thing with calcium chloride it's
got chloride in it same thing as sodium
chloride so chlorine wouldn't switch
with chlorine doesn't make any sense
wouldn't contribute and finally same
thing with potassium chloride chlorine
chlorine no reason for the reaction to
happen so there are the answers for our
sodium chloride series now we're looking
at our calcium hydroxide reaction series
we've got about two to three milliliters
of calcium hydroxide in each of these
test tubes calcium hydroxide is pretty
much insoluble in water so we basically
have kind of a little bit of cloudiness
in these most of the calcium hydroxide
is settle to the bottom line container
it looks like this
so we're gonna see what we can see here
we're gonna put our copper sulfate in
the first one and then hydrochloric acid
sodium hydroxide calcium chloride and
potassium chloride let's start with our
copper sulfate
hydrochloric acid
sodium hydroxide
calcium chloride
and potassium chloride
okay looking at these don't see much
indication of a reaction except looking
at our copper sulfate here let's see if
we can focus in on that there's some
cloudiness it looks like a precipitate
is forming
see what happens if we add some of our
solid to these
oh yeah if you look at the copper
sulfate it reacts pretty much instantly
it's chunky
kind of an inconsistent texture in there
all the rest of these kind of look like
we expect them to just kind of cloudy
with the possible exception of with the
HCL here with the HCL it precipitated
almost immediately right out to the
bottom so those two seem very different
from the rest so the HCL in the copper
sulfate seem to react right away the
rest of these just kind of look cloudy
and insoluble like copper sulfate
typically does this is the calcium
hydroxide up close calcium hydroxide
that was formed in the reaction between
I'm sorry not calcium hydroxide copper
sulfate that was formed in the reaction
between copper sulfate and calcium
hydroxide it formed this calcium sulfate
kind of snotty looking stuff in there
okay so here are the answers for our
calcium hydroxide activity series this
is kind of a weird one to do because the
calcium hydroxide is already insoluble
in water so it's kind of hard to see any
sort of reaction at all except in the
case of the calcium hydroxide and the
copper sulfate so in this one basically
the calcium in the copper switched place
and we end up with calcium sulfate which
is insoluble which kind of forms this
kind of like almost snot looking stuff
you can see that they're real pretty
with our hydrogen chloride or a
hydrochloric acid you can see a reaction
happen right away - and that it's
settled much faster than all of our
other ones with that particular reaction
what happens is the calcium from the
calcium hydroxide kind of gloms on to
the chlorine from the hydrochloric acid
we end up with calcium chloride which is
water-soluble and the OAH from the
calcium hydroxide gloms onto the
hydrogen from the hydrochloric acid and
we form water so what this does is it
takes a lot of the stuff out of solution
and makes it soluble and basically that
that insoluble stuff is left in the
bottom that's just unreacted calcium so
if we formed soluble compounds why do we
why did this reaction happen well it's
because water was formed as you know
water is a covalent compound and one of
the reasons for a double displacement
reaction to happen is the formation of a
covalent compound so for this activity
series we did not have any reactions
with the three on the right that's the
sodium hydroxide the calcium chloride
and the potassium chloride we did have
reactions with the copper sulfate where
a solid was formed
that's the calcium sulfate and with the
hydrochloric acid where it basically
neutralized to form water hydrochloric
acid you'll learn later is a strong acid
and the calcium hydroxide is a base so
there you go
all right next up we have our copper
sulfate activity series the copper
sulfate to begin with kind of has this
beautiful blue color
let's add our second reactants so we're
going to start with some hydrochloric
acid sodium hydroxide
some calcium chloride
and some potassium chloride
well it looks like right away we have
some reactions
the most obvious of which would be the
sodium hydroxide when the copper sulfate
reacts with the sodium hydroxide we
basically get copper hydroxide and
sodium sulfate and the copper hydroxide
is insoluble so we get this kind of
goopy looking precipitate forming up at
the top and a layer these other three
show no change really they kind of all
look the same
in fact for copper sulfate and calcium
chloride it looks just like water and
for copper sulfate and potassium
chloride again no significant change
here no significant change interesting
all right now we're looking back at our
copper sulfate samples and we can see
pretty clearly now that a reaction has
occurred with the calcium chloride we're
seeing precipitate form and start to
fall to the bottom
we already saw the reaction happen with
the sodium hydroxide we can see a little
better now but clearly that ones happen
as well we still can't see the reaction
with the hydrochloric acid we'll have to
use some sort of indicator to suss that
out okay now it's time for our
hydrochloric acid tests we got some HCL
in there so in there and
some in there so the first one we're
gonna add sodium hydroxide we predict
your reaction here so do my Drock sides
and base doesn't look like anything's
going on let's add our calcium chloride
and our potassium chloride and we see no
visible reaction all right with our
hydrochloric acid we predicted that the
sodium hydroxide would react that the
sodium would leave the hydroxide go to
the chlorine form salt sodium chloride
and we'd also get water covalent
compound but we didn't see any evidence
of that we predicted that these two both
chloride compounds wouldn't react right
because why would chlorine replace
chlorine doesn't make any sense okay
and I actually makes sure if this if
didn't reaction didn't happen let's add
a little bit of indicator so I'm gonna
put in some phenolphthalein
and in all three of these we get kind of
a milky looking solution Fila failing is
an indicator that should turn kind of
bright pink eye in the presence of a
base so let's add some base
you can see as soon as I add the sodium
hydroxide the solution turns pink but
then it quickly turns back to this kind
of milky color let's just keep adding
starting to stay pink let's see if
that's enough to make it stay nope keep
going
and now our solution has a nice rich
pink color let's see if that's true with
these other two keep adding some
chlorine so calcium chloride nope I can
add calcium chloride all day and I won't
get that reaction sans try the same with
potassium chloride nope and nope
okay so adding those two until my
heart's content I don't see the
indicator work with the addition of the
phenolphthalein it most definitely does
work
so there you go this one actually did
have a chemical reaction even though we
couldn't first see it we had to use some
other chemical means to see that
reaction and again with our sodium
hydroxide and our hydrochloric acid this
is called a neutralization reaction
you'll learn about it later basically we
take a base and an acid atom together
and you get mostly water and all water
if you do it perfectly and then some
other sort of compound in this case it's
salt sodium chloride okay there you go
so here we have some hydrochloric acid
we're gonna add some pure sodium
hydroxide and see what happens
okay now we have two test tubes filled
with our sodium hydroxide let's put in
some calcium chloride and some potassium
chloride I don't see any evidence of a
reaction right now but let's give it
some time okay now we can see that no
reaction happened with the potassium
chloride but with the calcium chloride
we have a lot of precipitate formed so
definitely a reaction happened there
with the sodium hydroxide reactions the
reason it reacted with calcium chloride
is because it forms calcium hydroxide
and calcium hydroxide is not soluble in
water so that's why we see this
precipitate form our last reaction is
calcium chloride we're gonna stick some
potassium chloride in there and we see
no reaction right both of them are
chlorides so there's no reason to trade
because they're both already bonded to
chlorine so no reaction
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