Determining Concentration Using Density

Summary

In this DIY chemistry video, the host sets up a makeshift lab in his room to experiment with hydrogen peroxide concentration. He aims to increase the concentration of a 30% hydrogen peroxide solution by heating it, hoping to boil off some of the water content. The host measures the initial density of the solution and then heats it on a hotplate, carefully monitoring the temperature to avoid decomposition. After 20-30 minutes, the volume has significantly reduced, and the density is remeasured. The experiment concludes with a slight increase in density, suggesting a minor concentration boost, although the host acknowledges the complexity of the process and the potential for decomposition.

Takeaways

• 🧪 The video is set in a makeshift lab in the creator's room with a card table, emphasizing the casual and improvised nature of the experiment.
• 🔬 The creator is wearing casual protective gear, highlighting the DIY aspect of the experiment and reminding viewers to prioritize safety.
• 🌡️ The experiment involves concentrated hydrogen peroxide, which the creator has previously concentrated and compared with store-bought versions.
• 📈 The creator references a graph showing the relationship between the density (specific gravity) and the concentration of hydrogen peroxide solutions, indicating that higher concentrations are denser.
• 📝 The method used to determine the concentration of hydrogen peroxide is based on its specific gravity, which is less precise but more accessible than titration.
• 🧴 Safety precautions are emphasized, including wearing safety equipment, storing hydrogen peroxide in amber bottles to prevent decomposition, and relieving pressure regularly.
• ♨️ The experiment involves heating the hydrogen peroxide to increase its concentration by evaporating water, with the hypothesis that the concentration will rise post-heating.
• 🌡️ Monitoring the temperature during the heating process is crucial to avoid decomposition of hydrogen peroxide, which boils at a higher temperature than water.
• 🔍 The creator measures the initial density of the hydrogen peroxide solution before heating, aiming to compare it with the density after the process.
• 🔄 After heating, the volume of the solution is significantly reduced, suggesting some concentration of the hydrogen peroxide may have occurred.
• 📊 The final density measurement shows a slight increase, indicating a minimal concentration change, though the creator acknowledges the complexity of the results due to potential decomposition.

Q & A

What is the purpose of the experiment in the video?

The purpose of the experiment is to increase the concentration of hydrogen peroxide by heating it and measuring the change in its specific gravity (density).

What is the initial setup of the lab in the video?

The lab is set up temporarily in the presenter's room with a card table, and the presenter is wearing casual protective gear, indicating a non-professional but safe environment.

What is the significance of measuring specific gravity in determining the concentration of hydrogen peroxide?

Specific gravity is a measure of the density of a substance relative to water. In the case of hydrogen peroxide, a higher concentration corresponds to a higher density, making it a practical method for estimating concentration without precise titration equipment.

What safety precautions are mentioned in the video?

The presenter mentions wearing safety equipment, storing hydrogen peroxide in a dark area to prevent decomposition, and relieving pressure from the bottle regularly to avoid buildup and potential explosion.

Why is it important to monitor the temperature during the heating process in the experiment?

Monitoring the temperature is crucial to prevent the decomposition of hydrogen peroxide and to ensure that only water is being boiled off, which helps in increasing the concentration of the hydrogen peroxide solution.

What is the boiling point of water and how does it compare to that of hydrogen peroxide?

Water boils at 100 degrees Celsius, whereas hydrogen peroxide boils at around 150 degrees Celsius. This difference allows for the heating of the solution to boil off water without boiling the hydrogen peroxide.

What is the initial hypothesis of the experiment?

The initial hypothesis is that heating the hydrogen peroxide solution will increase its concentration by boiling off some of the water, thus increasing the density of the solution.

How does the presenter adjust the hypothesis during the experiment?

The presenter adjusts the hypothesis during the experiment, suspecting that the concentration might not increase significantly due to the decomposition of hydrogen peroxide at higher temperatures.

What is the final observation regarding the change in density after heating the hydrogen peroxide solution?

After heating, the density of the hydrogen peroxide solution slightly increased from 1.015 to 1.0469 g/mL, indicating a minimal increase in concentration.

What is the conclusion of the experiment?

The conclusion is that heating the hydrogen peroxide solution did result in a slight increase in concentration, as evidenced by the change in density, but the effect was minimal and the process also caused some decomposition of the hydrogen peroxide.

Outlines

00:00

🧪 Experimenting with Hydrogen Peroxide Concentration

The video begins with the host setting up a makeshift laboratory in his room, using a card table and wearing casual protective gear. The main focus of the experiment is to increase the concentration of hydrogen peroxide beyond the 30% store-bought variety by using a homemade concentrated solution. The host references a previous video and provides links to related playlists. The method for determining the concentration involves measuring the specific gravity or density of the hydrogen peroxide, which correlates with its concentration. The host emphasizes safety precautions, such as wearing proper safety gear and storing hydrogen peroxide in amber bottles to prevent decomposition due to light exposure. The experiment's hypothesis is that heating the hydrogen peroxide will increase its concentration, and the host plans to measure the density before and after heating to test this.

05:01

🔍 Measuring Hydrogen Peroxide Density and Heating Experiment

The host proceeds with the experiment by carefully measuring the hydrogen peroxide's volume and mass to calculate its initial density. He observes bubbling when adding the peroxide to the graduated cylinder, indicating some level of reaction. After determining an initial density of 1.0151 grams per milliliter, the host transfers the solution to a beaker and places it on a hotplate to heat. The goal is to boil off some of the water, thereby increasing the concentration of hydrogen peroxide. The host monitors the temperature and notes the difference in boiling points between water and hydrogen peroxide, which is crucial for the experiment's success. After some time, the host observes vapor and notes that the solution is boiling, but he suspects that some hydrogen peroxide may also be decomposing, which could affect the experiment's accuracy.

10:03

📉 Analyzing the Effects of Heating on Hydrogen Peroxide

After heating the hydrogen peroxide solution for approximately 20 to 30 minutes, the host notes a significant reduction in the solution's volume. He then allows the solution to cool before re-measuring its mass and volume to calculate the new density. Despite the initial hypothesis that heating would increase the concentration, the host's calculations reveal a decrease in density from 1.0151 to 1.0469 grams per milliliter, suggesting that the concentration has not increased as expected. The host acknowledges that the results are not as clear-cut as anticipated, possibly due to the decomposition of hydrogen peroxide during the heating process. The video concludes with the host summarizing the experiment's findings and thanking the viewers for watching.

Keywords

💡Hydrogen Peroxide

Hydrogen peroxide is a chemical compound with the formula H2O2. It is a pale blue liquid that is used as an oxidizer, bleaching agent, and antiseptic. In the video, the creator is working with hydrogen peroxide to increase its concentration through heating, which is a central theme of the experiment.

💡Concentration

Concentration in chemistry refers to the amount of a particular substance in a given volume of solution. It is a key concept in the video, as the experiment aims to increase the concentration of hydrogen peroxide by heating and removing water content.

💡Specific Gravity

Specific gravity is the ratio of the density of a substance to the density of a reference substance, usually water. In the context of the video, specific gravity is used to estimate the concentration of hydrogen peroxide, as denser solutions imply a higher concentration.

💡Density

Density is a measure of mass per unit volume of a substance and is expressed in grams per milliliter (g/mL). The video discusses measuring the density of hydrogen peroxide to determine its concentration before and after heating.

💡Safety Equipment

Safety equipment refers to protective gear used to prevent personal injury. In the video, the creator humorously mentions wearing shorts as 'protective gear' but stresses the importance of proper safety measures when handling chemicals.

💡Decomposition

Decomposition in chemistry is a chemical reaction in which a compound breaks down into two or more simpler substances. The video discusses the decomposition of hydrogen peroxide when heated, which can lead to the formation of water and oxygen.

💡Boiling Point

The boiling point is the temperature at which a substance changes from a liquid to a gas. The video mentions the boiling points of water and hydrogen peroxide to explain the process of heating the solution to remove water and concentrate the hydrogen peroxide.

💡Titration

Titration is a laboratory technique used to determine the concentration of a solution. The video mentions titration as a more precise method to determine the concentration of hydrogen peroxide, but the creator opts for a less precise method due to lack of equipment.

💡Opaque Bottles

Opaque bottles are containers that do not allow light to pass through, which is important for storing substances like hydrogen peroxide that can decompose when exposed to light. The video advises storing hydrogen peroxide in such bottles to prevent decomposition.

💡Pressure Relief

Pressure relief refers to the release of built-up pressure in a container. The video explains the importance of relieving pressure in hydrogen peroxide containers to prevent dangerous build-up that could lead to an explosion.

💡Experiment

An experiment is a scientific procedure undertaken to make a discovery, test a hypothesis, or demonstrate a known fact. The video documents an experiment where the creator attempts to increase the concentration of hydrogen peroxide by heating it, which is the main educational content of the video.

Highlights

Introduction to a new experiment in a temporary lab setup with a homemade concentrated hydrogen peroxide.

Discussion on the importance of safety and the use of protective gear during chemical experiments.

Explanation of the concept of specific gravity and its relation to the concentration of hydrogen peroxide.

The plan to determine hydrogen peroxide concentration based on its specific gravity.

Mention of the limitations of using specific gravity for precise concentration measurements compared to titration.

Instructions on safely storing hydrogen peroxide to prevent decomposition and pressure build-up.

Demonstration of measuring the volume and weight of hydrogen peroxide to calculate its density.

Observation of bubbling during the measurement process indicating hydrogen peroxide's reactivity.

Calculation of the initial density of the hydrogen peroxide solution.

Hypothesis that heating the hydrogen peroxide will increase its concentration by removing water.

Monitoring the temperature during the heating process to prevent decomposition of hydrogen peroxide.

Observation of vapor rising and the solution boiling, indicating the progress of the experiment.

Adjustment of the hypothesis due to the potential loss of hydrogen peroxide through decomposition during heating.

Decision to stop the experiment after a significant reduction in the solution's volume.

Recalculation of the density after heating to determine if the concentration has increased.

Conclusion that the density has slightly increased, suggesting a minimal increase in concentration.

Final thoughts on the experiment's outcome and the practicality of the method used for concentration determination.

Transcripts

hey how's it going everybody welcome

back to a brand new video today in the

temporary lab set up in my room actually

this is that this is a card table yeah

very professional laboratory setup as

always also I am wearing very protective

gear shorts and stuff very very good

idea anyway today we're gonna be messing

with this stuff which is this is a

hydrogen peroxide which I concentrated

myself and the store-bought stuff on a

previous video link will be up there and

probably in the description also the

Josh the nerd

Josh's lab playlist will be up there as

well if you want to check out more

videos anyway back to what we're doing

today I was searching through my

Chemical Mike my Chemical stores up

there and I remembered this but I didn't

actually see how far I can get the

concentration so we're gonna be seeing

if we can up the concentration today if

we can great if not then we'll know that

about 30 percent is the max now over on

my computer I have that which is the

density slash specific gravity specific

gravity is basically just density of

hydrogen peroxide solutions as you can

see on the graph it gives you the

density in grams Leela ya grams per

milliliter

with that the concentration of h2o - so

yeah so the higher the concentration as

a percentage the the denser is which

makes sense because hydrogen peroxide is

more dense than water right so that

makes sense now what we're gonna be

doing today is we're gonna be taking

this hydrogen peroxide and we're gonna

be determining the concentration based

off its specific gravity which actually

is a very good way of doing it because

you lose a lot of sig figs and it's not

very accurate but it's better than

nothing

if you if you are doing this yourself

and you have and you really want to

figure out the exact concentration with

very high precision then a titration

would be way better but I don't have the

equipment for that right now so we're

gonna be going with this method so what

we're gonna do is we're gonna constant

gloves here because safety is number two

priority on adjusting our

youtube-channel few warnings before we

start make sure you're wearing safety

equipment you have basic I could I could

do way better by actually wearing actual

equipment but Yolo am i right when

storing this stuff put it in a bottle

that absorbs a decent amount of light

like an Amber bottle reason why it's

stored in opaque bottles like if you

went to a Dollar General your hydrogen

peroxides gonna be in an opaque bottle

so it absorbs the light and the light

doesn't actually go into the peroxide

because hydrogen peroxide decomposes

quite a bit pressure will build up

inside these bottles and so you're

storing hydrogen peroxide make sure to

put in a dark area also make sure to

relieve the pressure

I recommend every week - every few weeks

at least that's how I've been doing it

it's not gonna do it now because I did

it like ten minutes ago

but open up the bottle right there let

out a lot of pressure so if you've

enough pressure build-up in these then

you're gonna have a bomb be careful

that's not what we're about right so

yeah

so there's that this was concentrated

let's see a few months ago so hopefully

it'll work for what we're doing we're

gonna do is we're gonna we're gonna

measure the density aka the specific

gravity of this then we're gonna heat it

for some time then we're gonna measure

the specific gravity of that and if it

if the concentration is higher here's

here's your here's hypothesis all right

the concentration of this should be

higher after heating it so that's the

that's the idea

if it works or not we're going to see so

the first thing we're going to do is

we're going to measure the

the volume and the weight of this so we

can calculate density all right probably

won't need goggles for this but whatever

good practice to have it on anyway all

right so we're gonna do is we're gonna

take C this is about ten number comedy

don't worry use the fifty milliliter

graduated cylinder history just in case

whose dew point nine grams we're gonna

tear that and the right head down

actually on the chalkboard no I'm gonna

tear that we ran add the peroxide very

carefully over that its tenth season

actually let me observe this for a

second huh okay so there's a lot of

bubbling going on so we've agitated it

and we're at 40 point one grams

I'd say thirty nine point five

milliliters we're gonna go over the

calculations ignore the mess on the on

the table here all right so we have

fifty two point nine grams which is our

edge weighted cylinder so that's really

matter so now we can do the math so it's

fine density density equals mass divided

by volume that's pretty common knowledge

so our mass our mass is forty 0.1 grams

and our volume is thirty nine point four

five milliliters a lot of strikes in the

spit area which is our density I'll just

write over here actually density will

equal one point zero one five one so

that is our

current density so if that changes that

number changes there we should have a

different concentration okay so let's

just keep that in mind now we're back

over at the station and I'm going to

pour this right into here just like so

make sure you get as much in there as

possible I would watch this but it's

gonna mess with the calculation so we're

just gonna have to deal a little bit of

percent error in our math just fine

gonna we're gonna crank up the heat a

hotplate and get her heat it up so the

idea with this is that what we're gonna

do is we are going to we're going to

heat this up right I want to boil off

some of the water and hopefully that'll

increase the concentration I could run a

distillation for this I love that's

necessary

one thing they have to be careful of

though is that if we keep this too much

it's going to decompose the hydrogen

peroxide through that it's gonna add

even more error to the math but where

this works tend to live in that

so I'm actually curious myself to see if

the density does change so I'll be

interesting to look at it's been a few

minutes and I've been monitoring the

temperature which is really important Oh

[Music]

see a little bit of vapor rising now

it's getting hot I'll make sure if

you're doing this to monitor the

temperature because it's very important

because water as you know boils at 100

degrees centigrade

but a hydrogen peroxide boil that one

around 150 degree centigrade so the only

reason why we're able to do this in the

first place is because they haven't

they're they differ in boiling points

currently at about 60 degrees centigrade

okay the solution is boiling quite

vigorously but I think that's only two

things I think it's just a the water

boiling and V and B the hydrogen

peroxide decomposing because there's no

way that it's that's hydrogen peroxide

is boiling right now we're really

sitting at about ninety degrees

centigrade we could take it off now but

it's only been like 15 minutes tops

ah you know what that's a boiling quite

a bit but again I'm just guessing it's

decomposition of the hydrogen peroxide

you know what words gonna leave it for a

while and see what happens I'll put the

turn the heat back up

actually I'm now going to change my

hypothesis because I don't think that

this is gonna get very much more

concentrated cuz we're gonna lose a lot

more

hydrogen peroxide doing this so our

results are not going to be as black or

white as you mix as you may think we're

probably going to get a mixture of both

sides because yes we are reducing the

water content or also reducing the

hydrogen peroxide content from

decomposition so I guess we'll just see

what happens I'm curious man okay so

it's been about 20 to 30 minutes since

we first started the experiment and the

volume of the solution has been reduced

to quite significant amount so I think

that's actually where we're gonna stop

and we're going to whoop sorry about

that my my camera just decided to not

work for a second there or whatever so

there is our beaker it's cooled off for

quite some time it's cool enough that I

can hold it quite well and there is our

solution so now we can redo the

calculations and see the density has

changed at all

I didn't bother drying it out because

the little amount of hydrogen peroxide

here really shouldn't mess up our math

at all I just want to see if the numbers

change at all not really here to do a

full-scale calculation but we can do

that later so I'm going to tear that

we're gonna add this very carefully

probably wear gloves while doing this by

the way so we're sitting at 15.6 volume

at about let's see so that would be 15

so I would say about fourteen point nine

mils we do the math I'll bring the

camera over so those are our new numbers

right there what we're gonna do there

any density equal mass divided by volume

mass of two point six grams its volume

of fourteen point nine

milliliters so our new density fifteen

point six divided by fourteen point nine

oh would you look at that our new

density is one point zero four six nine

three significant figures and so we went

from move those test tubes or our

initial density was one point zero two

and our new density is one point zero

five so that means we have a difference

of 0.03 grams per milliliter of density

and so there you go more we heat up more

concentrated against again that's that's

a very very small amount and I also had

a very low amount of peroxide here and

yeah that's basically all I have for

today so thanks for watching this video

and and uh look forward to some more in

the future have a good one