LAB 4 Chemical Reactions

Summary

This chemistry lab video demonstrates various chemical reactions using a 12-well plate and test tubes. Key reactions include the mixing of silver nitrate and sodium chloride, leading to a dramatic color change, and the combination of lead nitrate with potassium iodide. The video also explores reactions between zinc nitrate and potassium carbonate, iron nitrate with potassium hydroxide, and sodium phosphate with calcium nitrate. Additionally, it shows neutralization reactions with sodium hydroxide and hydrochloric acid, as well as reactions involving mossy zinc with copper sulfate. Each reaction is carefully observed for color changes, temperature, and gas production, providing a visual and educational experience.

Takeaways

• 🧪 The video is a chemistry lab demonstration focusing on chemical reactions.
• 📏 The lab involves mixing chemicals in a 12-well plate and observing the reactions.
• 🔍 The first reaction shown is between silver nitrate and sodium chloride, resulting in a colorless and transparent mixture.
• 📈 The script emphasizes the importance of observing changes before and after mixing chemicals.
• 🌐 The reactions are described with a focus on the physical changes, such as color and transparency.
• 📝 Students are encouraged to describe their observations in their own words.
• 🔬 The video mentions potential issues like contamination or old chemicals affecting the reactions.
• 🧫 Some reactions are conducted in test tubes instead of the 12-well plate, such as the reaction between sodium hydroxide and hydrochloric acid.
• 🌡️ Observations include changes in temperature, cloudiness, and the production of gas.
• ⚗️ The reactions involve a variety of chemicals, including zinc, copper sulfate, and mossy zinc.
• 🔥 One of the reactions produces a gas that can be ignited, demonstrating a chemical reaction that releases energy.

Q & A

What is the purpose of the video?

The purpose of the video is to demonstrate various chemical reactions in a lab setting, specifically by mixing different chemicals and observing the reactions.

What are the first two chemicals mixed in the video?

The first two chemicals mixed in the video are silver nitrate and sodium chloride.

What is the significance of the numbers before the chemical names?

The numbers before the chemical names represent the concentrations of the chemicals, expressed in molarity (M).

How much of each chemical is mixed in the first reaction?

In the first reaction, three drops of each chemical are mixed into one of the wells of a 12-well plate.

What is observed when silver nitrate and sodium chloride are mixed?

A dramatic change is observed when silver nitrate and sodium chloride are mixed, indicating a chemical reaction.

What are the next set of chemicals mixed after silver nitrate and sodium chloride?

The next set of chemicals mixed are lead nitrate (Pb(NO3)2) and potassium iodide (KI).

What is the observation made when lead nitrate and potassium iodide are mixed?

The script does not explicitly mention the observation for the lead nitrate and potassium iodide reaction, but it encourages the viewer to describe what they observe.

What is the issue with the iron nitrate solution in the video?

The iron nitrate solution appears to be contaminated or old, with some solid precipitation at the bottom of the bottle, which is not supposed to be there.

What is the expected outcome of mixing iron nitrate and potassium hydroxide?

The expected outcome is a precipitation reaction, where the solution should become cloudy upon mixing.

How are the reactions in the test tubes different from those in the 12-well plate?

The reactions in the test tubes involve different chemicals and are carried out in a different environment, often involving the use of pipettes and observing temperature changes or gas production.

What is the observation when sodium hydroxide and hydrochloric acid are mixed in a test tube?

The observation is a warm or hot reaction, with possible condensation on the walls of the test tube.

What happens when zinc (referred to as mossy zinc) is added to hydrochloric acid?

A reaction occurs that produces fizzing, and when a match is held over the test tube, the gas ignites with a chirping sound.

Outlines

00:00

🔬 Chemical Reactions in a Lab

This paragraph introduces a lab video focused on chemical reactions. The presenter begins by mixing chemicals in a 12-well plate. The first reaction involves mixing silver nitrate and sodium chloride, both at concentrations indicated by '1M' and '0.1M' respectively. The presenter emphasizes observing the reactions before and after mixing, noting the dramatic change when the two chemicals are combined. The reaction produces a colorless and transparent solution. The video continues with reactions involving lead nitrate and potassium iodide, zinc nitrate and potassium carbonate, and iron nitrate and potassium hydroxide. The presenter points out a potential issue with the iron nitrate solution, suggesting it may be contaminated. The reactions are observed for changes in color, transparency, and the formation of precipitates.

05:01

🧪 Observations and Additional Reactions

The second paragraph continues the lab demonstration with a focus on observing chemical reactions. The presenter discusses a reaction involving sodium phosphate and calcium nitrate, noting a visible reaction. The video then transitions to reactions in test tubes, starting with a combination of sodium hydroxide and hydrochloric acid. The presenter uses a pipette to measure out specific volumes of the chemicals and observes a warming effect and cloudiness along the test tube walls. The next reaction involves hydrochloric acid and sodium carbonate, with the presenter noting the formation of bubbles. The paragraph concludes with a reaction using 'mossy zinc' and hydrochloric acid, where the presenter demonstrates the fizzing reaction and the ignition of gas produced.

10:08

🌀 Combining Zinc with Acids and Copper Sulfate

In the third paragraph, the presenter explores reactions involving zinc. First, zinc is combined with hydrochloric acid, resulting in a fizzing reaction and the production of gas. The presenter then lights a match over the test tube to ignite the gas, creating a 'chirping' sound. The next reaction involves adding mossy zinc to copper sulfate, leading to observable changes in the zinc's appearance. The presenter instructs viewers to note the differences in the zinc over time, emphasizing the importance of careful observation in chemical experiments.

15:10

📝 Conclusion and Observation Notes

The final paragraph is a brief conclusion to the lab demonstration, focusing on the changes observed in the zinc over the course of the experiment. The presenter encourages viewers to document their observations, particularly the differences in the zinc's appearance before and after the reactions. This paragraph serves as a reminder of the importance of detailed note-taking in scientific experiments.

Keywords

💡Chemical Reaction

A chemical reaction involves a change in the arrangement of atoms, leading to the formation of new substances. In the video, chemical reactions are demonstrated through various experiments, such as mixing silver nitrate and sodium chloride, which results in a visible change indicative of a reaction. The script describes observing these changes, which is central to understanding chemistry.

💡Concentration

Concentration refers to the amount of a substance present in a given volume of solution, often expressed in molarity (M). The script mentions '0.1 M' and '1 M' to describe the concentration of solutions like silver nitrate and sodium chloride, which is crucial for conducting accurate chemical reactions and understanding their outcomes.

💡Silver Nitrate

Silver nitrate is a chemical compound often used in educational settings to demonstrate precipitation reactions. In the video, silver nitrate is mixed with sodium chloride, leading to a visible reaction. The script describes the observation of this reaction, emphasizing the importance of careful observation in chemistry.

💡Sodium Chloride

Sodium chloride, commonly known as table salt, is a colorless and transparent solution when dissolved in water. The script describes it as 'colorless transparent solution, kinda looks like water,' highlighting its appearance and how it behaves in reactions, such as when it reacts with silver nitrate.

💡Lead Nitrate

Lead nitrate is another chemical compound used in the video to demonstrate reactions. When mixed with potassium iodide, as described in the script, it results in a reaction that the viewer is encouraged to describe in their own words, illustrating the active engagement with chemical processes.

💡Zinc Nitrate

Zinc nitrate is mentioned in the context of mixing with potassium carbonate. The script suggests that this reaction might be slower, indicating that the rate of chemical reactions can vary. This is an important concept in chemistry as it influences the observation and timing of experiments.

💡Iron Nitrate

Iron nitrate is highlighted in the script when discussing potential contamination and precipitation reactions. The observation that the iron nitrate solution is not colorless suggests impurities, which could affect the outcome of the reaction. This keyword underscores the importance of reagent purity in chemical experiments.

💡Sodium Hydroxide

Sodium hydroxide, also known as lye, is a strong base used in the video to demonstrate a reaction with hydrochloric acid. The script describes the reaction as exothermic, noting that the test tube becomes warm, which is a practical demonstration of energy changes during chemical reactions.

💡Hydrochloric Acid

Hydrochloric acid is a strong acid used in several reactions throughout the video. When mixed with sodium hydroxide, it forms a neutralization reaction, producing heat and water. The script's mention of this reaction provides a clear example of an acid-base reaction and its thermal effects.

💡Mossy Zinc

Mossy zinc, or granular zinc, is used in the video to react with hydrochloric acid, producing hydrogen gas. The script describes the fizzing observed, which is due to the release of gas, a common phenomenon in acid-metal reactions. This keyword is important for understanding gas evolution reactions.

💡Copper Sulfate

Copper sulfate is highlighted in the script when reacting with mossy zinc. This reaction is noted for the change in the zinc's appearance, illustrating how chemical reactions can alter the physical properties of substances. It serves as an example of a single displacement reaction in the video.

Highlights

Introduction to a chemistry lab video focusing on chemical reactions.

Mixing chemicals in a 12 well plate for reactions.

First reaction involves mixing silver nitrate and sodium chloride.

Observing the colorless and transparent nature of NaCl solution.

Silver nitrate solution's transparency despite its container's dark color.

Chemical reaction observed upon mixing silver nitrate and sodium chloride.

Second reaction with lead nitrate and potassium iodide.

Observation of colorless and transparent nature of lead nitrate and potassium iodide solutions.

Third reaction involves zinc nitrate and potassium carbonate.

Fourth reaction with iron nitrate and potassium hydroxide, noting possible contamination.

Observation of cloudiness in iron nitrate solution suggesting contamination.

Fifth reaction with sodium phosphate and calcium nitrate showing clear reaction.

Transition to reactions in test tubes instead of 12 well plates.

Sixth reaction combining sodium hydroxide and hydrochloric acid.

Observation of warmth and condensation during the reaction.

Seventh reaction with hydrochloric acid and sodium carbonate.

Observation of bubbling during the reaction.

Eighth reaction combining mossy zinc with hydrochloric acid.

Observation of fizzing and gas production.

Ninth reaction combining mossy zinc with copper sulfate.

Observation of changes in zinc's appearance during the reaction.

Transcripts

so this is a video for lab for chemical

reactions and we're gonna begin by

mixing chemicals into a 12 we'll plate

in this first reaction we're gonna mix

silver nitrate and sodium chloride and

these numbers in front of the word of

the compounds are the concentrations

which we haven't learned about yet but

you see the point 1 capital M is the

concentration so when we grab the bottle

we just want to make sure that we have

the bottle at this point 1 and silver

nitrate and also 0.1 NaCl so all of the

reactions that we're going to be doing

you want to make observations that are

shot before and after and what you want

to notice is that in particular the NaCl

is just a colorless transparent solution

kinda looks like water and it is

basically that's essentially salt water

for your silver nitrate it's hard to

tell because it's in a color dark a

colored container but if I hold it at

the right angle you can kind of get the

sense that it - is this it's a solution

and the solution is transparent -

meaning you can see through it and so

you want to observe what happens once

you mix the two things together so let's

go ahead and mix point three drops of

each thing into one of the wells of our

12 ball plate

so yeah you can see pretty colorless

completely colorless and completely

transparent you can just see the well

right through the droplet now we're

going to add look at that drop it's

completely colorless and transparent and

as soon as the two drops mixed or two

met we had a dramatic change so that's a

chemical reaction and you just want to

write in your own words what you are

observing what your how you describe

this

and I think you might be able to see a

little bit um yeah yeah you can even

kind of lift some of that out of the

solution so just describe what happened

there in your own words okay next we're

going to do we have PB no3 and ki and

again they're both the point 1m solution

so we notice that this container has a

colorless transparent liquid in it and

the drops that are coming out are also

colorless and transparent so you have

three drops that that was the potassium

iodide and now we're going to add the

lead nitrate

so just describe your own words what

what happened there

okay next we have zinc nitrate and

potassium carbonate it doesn't really

matter what order you mix these em so

I'm going to get three drops of each

this reaction maybe is a little bit

slower but definitely see something

happened in their excrements me of

egg-drop soup

okay next we're doing iron nitrate and

potassium hydroxide

[Music]

this reaction is a little bit strange I

have to admit because I don't know if

you notice it I did but the droplet

wasn't colorless and it wasn't

transparent it seemed a little bit

cloudy going in I think our iron nitrate

might be a little bit contaminated we I

think we might have some iron

precipitation in the bottle itself let

me show you that bottle

real quick you can see from the bottle

that there's like maybe some solid stuff

in the bottom and it's definitely not

colorless so I think our iron nitrate

may be a little bit old and so we may

have already had some solid but you were

supposed to observe another

precipitation reaction here so it was I

think it was supposed to be transparent

and then it was supposed to precipitate

once you combine them that's what you're

gonna want to write to the answer and

that one make sure that you do record

that there was a precipitation reaction

with them okay then our fifth reaction

is with sodium phosphate and calcium

nitrate so let's go ahead and do this

one these ones are both clear and

transparent

and the colorless on transmitter clear

and transparent are the same name the

same thing something can be transparent

and also be colored transparent just

means you can see through it okay so

clearly we have some reaction

okay so that's our first five reactions

now the next five reactions are not

happening in 1200 plates so we are going

to set up some test tubes for that okay

so we have our test tube setup or a test

tube picked out here and to this test

tube we're going to combine some sodium

hydroxide and some hydrochloric acid so

NaOH plus HCL we're going to use a 1

milliliter pipette to do this and we're

just going to fill this pipette to the

this mark right here on the neck we need

2 milliliters of our 6 molar HCl to

start I'm going to fill it up twice

there you go that's good enough

so you want to make sure that the tip of

the pipette stays in the solution while

you're suctioning up the fluid whatever

or whatever it is that you're suctioning

there you go that's good

so you have two milliliters of the HCL

perfect we actually want to use a

different pipette to put into the three

molar sodium hydroxide because we're

using we're putting the pipette directly

into the container we don't want to

cross contaminate so I don't want to get

any of the HCL into this sodium

hydroxide - all right so we have two

milliliters of hydrochloric acid and

test tube and now we're adding in we're

going to add four milliliters of the

sodium hydroxide we want to try to

observe make any observations that we

can about what's happening in this

reaction so I want you to kind of notice

the cloudiness that's happening along

the walls of the test tube right above

the liquid level

and I want you to go ahead and touch the

test tube my assistant here is gonna

tell me go ahead and grab it with a few

fingers what do you think or say again

it's a warm it's getting hot it's

getting hot all right so those are the

observations that we want to make both

that you see you can see some sort of

like condensation on the wall of the

test tube and also it's getting hot all

right then

my next reaction is going to be on the

combination of a milliliter of six molar

HCl and 0.1 molar or 6m HCl endpoint and

three milliliters of 0.1 m na2co3 yeah

yep so we're going to put one pipette of

that of the 6m HCl

and then we're going to do three pipette

pulls of this the sitting parting what

do you see there what's happening there

too

ooh I feeling it nothing was happening

it's not warm this time it's not warm

and that was a super exciting reaction

hopefully you did notice that there were

bubbles and maybe you noticed that there

were more bubbles with the first

milliliter that we put end on the last

one okay next we have the combination

hydrochloric acid um HCl and a piece of

mosses ink so the Macias ink is the

stuff in the the vial there yeah that

stuff it's just ink basically but if I'm

sure why they go it Wasi um it's just

solid zinc and what we're gonna do is

combine some of this solid zinc with HCL

in a test tube all right so reaction

number eight combines mossie zinc with

six molar HCL so we're just gonna pour a

little bit of the zinc particles it's

actually just solid zinc I'm not sure

why it's called mossie but we're just

going to pour a piece or two of the

solid zinc into a test tube and then

we're going to add the right amount of

six more you see oh that's good so you

can kind of see it down there in the

test tube

litter this

so we're adding it in the HDL right now

and you can see

we're getting a lot of fizzing in part

two we're supposed to light a match and

hold it over the mouth of this test-tube

so we're gonna do that next and we want

to watch both what happens at the mouth

of the test tube and down at the bottom

of the test tube did you hear the sound

so any love you are able to see or

notice but again we have this sort of

cloudiness along the wall fantastic well

I did one more time you think that's

kind of dark background you gonna push

the test tube rack out of them lay there

so now we have the black background

it's not enough yes so we're waiting for

a buildup of the gas inside the test

tube and once we have enough of it in

there then we can light it and try again

you hear this little chirping sound as

the sound of the gas igniting all right

this is reaction number nine and in this

reaction we're going to combine going to

put some mossy zinc into three

milliliters of the cuso4 which is copper

sloping so we're going to put three

Millers the copper sulfate into this

test tube here and go ahead and make

some observations about the copper

sulfate in your notebook now

we're gonna add in the Massey's Inc

alright and this fraction doesn't happen

quite as dramatically but go ahead and

hook up the test tube and kind of shake

it around swirl it and can you make any

observations about what is happening

there's a little bubble there can you

can uh try to get it off so what is

happening to that zinc to the zinc what

looks different now than when it started

you

you

that's basically it for that one I mean

that you just wanted to notice the

difference in the zinc with time