The Limestone Cycle
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- čas přidán 15. 06. 2024
- The Limestone cycle is a key topic in GCSE Chemistry. We start with one of three forms of calcium carbonate, Chalk, Limestone or Marble. When Limestone is heated it undergoes thermal decomposition and releases CO2. We weigh the Limestone before and after to see the weight loss. The colour changes in the Limestone from Grey to the white of Calcium Oxide or Quicklime.
When water is added to the Calcium oxide, heat is given out and Slaked Lime is formed.
This is dissolved in water to give Limewater.
The Limewater is tested by blowing CO2 in it. The limewater turns cloudy. This is a precipitate of Calcium Carbonate. The Limestone cycle is complete.
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Thanks a lot for this wonderful demonstration!
Nice work Big Phil! From 10P1 2020
MrARHobbs i love you Big Phil😍😍
De mucha ayuda, muchas gracias, saludos desde Peru
What we’re going to do is watch this one more time and take a shot every time he narrates what we’re gonna do.
Wish this guy would have highlighted the tremendous energy input required to produce this lime. He was heating it for 10 minutes with a very small sample. Multiple that by millions of tons produced annually for industry and you can see why lime and, indeed, concrete production are energy-intensive processes with all their concomitant effects on resource depletion and global climate change
Thx for this vid. explanation! I enjoyed it and learned from it! Greetings from Morocco. ;)
Very cool. I’m simply looking to make my own quicklime, but I love see a bit of chemistry behind the process. (Yes, i know I can buy a more stable form of lime, but chemistry is fun.)
Thank you so much Philip Russel sir
Very helpful video. After some daydreaming I came up with a process to make sodium hydroxide from sodium bicarbonate. The basic process is I would decompose the bicarb with heat of ~200c into sodium carbonate, then further decompose the sodium carbonate into sodium oxide by heating it to at least 500c, and then react the sodium oxide with water to make lye. The problem with this is that while my initial research suggested that thermal decomposition of sodium carbonate produced only sodium oxide, upon further research I found it that it actually forms 80% sodium oxide and 20% sodium peroxide, and I've yet to find any easy way to separate the two. Also on top of that, the reaction is apparently very slow. So I did a bit more reading and decided that to make the sodium oxide, I could make calcium oxide from thermal decomposition of calcium carbonate and then react the calcium oxide with the sodium carbonate to make sodium oxide and go from there. This video provides a good deal of useful information for working out how to go about doing this. So I thank you for taking the time to post this. Best regards.
Very interesting! I have been trying to understand the various forms and states of calcium stone-derived substances such as plaster of Paris, limestone and Portland cement. It seems that people have created a lot of materials and technology by playing around with limestone!
A helpful and very useful video,presented in a very understandable layman's term.Great!
Glad it was helpful!
Awesome video 😁
Great vid!
this was a very useful and helpful video thankyou
Nice video. You can watch at 1.5 speed.
Isn't that when heated what they call (limelight) which burns brightly. It didn't seem illuminated?
Thank you!
very useful! thanks
Gracias exelente sencillo practico y facilmente de comprender gracias
Gracias. Tal vez con otras audiencias extranjeras tendré que hacer mis nuevos videos en muchos idiomas.
So what we are going to do?
Plese uncle say me how much time you heated that stone??
Thanks.
Thanks
question: why do we have to drop water on the CaO before dropping it in water?
The answer is you don't. The idea of putting a drop on it is to show the exothermic reaction.
Then you can see the slaking more clearly.
How long does the exothermic reaction last for roughly? I'm hoping to try and cook with it. Eggs, fish etc. Is it a clean burn or too toxic to cook over? If it's dangerous or toxic I won't try. Can it be added to dirty water to boil/purify after filtering ?
*and made safe to drink?
Depends on the amount. The more the longer. Some instant coffee's are heated this way add water and a container in a container ( keeping the food and the calcium oxide separate) heats the coffee to 60-70 Celcius. As for cooking I don't think it would be hot enough for long enough - otherwise we would all be doing it.
Hi Philip, do you mind if I use a five-second clip of you burning the chalk to illustrate a video about calcium carbonate?
Yes very happy to allow you.
Am I the only one who burst out laughing when he said "3117".....is that just me.
Thank you for good explnation
Glad it was helpful!
What was the weight of the powder lime that came from the limestone?
It was about 6g. For each 10g of Limestone, we get about 6g of Calcium Oxide. The smaller lumps give a better yield. The larger lumps do not all undergo thermal decomposition and we are left with some unreacted Limestone. In this video with a small lump, we made nearly all of it into Lime.
Great video! Can marble be calcined?
Marble, Chalk and LImestone are all made from Calcium Carbonate. Marble is typically harder than the other two, but can be heated in the same way and produces exactly the same chemical reaction
@@PhilipRussell Thanks. But doesn't marble trap the CO2 due to its non-porous nature?
In the reaction between hydrated lime and the carbon dioxide, once the water evaporates, will it actually mold back into stone? Or will it be dusted limestone? Thanks for the video!
The answer depends on the conditions. What is left is essentially dust and if allowed to dry it will blow away. If it stays wet ish - so it does not blow away and then it is squashed by something - other layers of sand mud clay etc forming above it then it will gradually be turned back to stone.
@@PhilipRussell You're awesome, thank you! I'm wondering if there's a way to accelerate this process without the need of water or any substitute equivalent.
@@alejandrotenorio2327 no sorry that’s chemistry
good one😎
Some times voice is not clear
However a good explanation
Do you let the CaO cool first then put the water in?
Yes. But the reaction of Calcium Oxide and Water is exothermic so it will give out heat.
LOVE IT
Agreed sexy
What is the formula for the reaction
Calcium Carbonate + Heat => Calcium Oxide + Carbon Dioxide
3:30 rip headphone users
How long do you need to cook the limestone? Say 1kg?
Time is not as important as temperature. You need the Calcium Carbonate/Oxide to glow red hot. This is normally above the temperature of a normal oven. Once the Calcium Carbonate/oxide is glowing red hot then it only takes a few minutes. The size of the material is also very important. The larger the lumps then the longer it takes.. Small pieces about 1cm cube or less takes about 10 minutes once they are red hot.
Thanks for your reply. I see. I've been doing a bit of research and seems like the temp of the kiln needs to be at a constant ~1100 degrees celsius. I'll assume it will then take roughly around 30 minutes for 3cm or larger chunks of limestone weighing about a kilo. I hope I am close enough with my estimates.
That sounds about right.
It just takes a long time. The hotter the reaction the faster it goes, but if you have the time then as long as it is hot enough to get the reaction going then it will work. It doesn't work in a normal oven but if you can get it to around 1000 degrees then it might go. The Ca is not really holding onto the CO2 - it is chemically joined. Lowering the pressure will have virtually no effect . Heat is needed to break the bonds and that energy doesn't change in a partial or full vacuum
Roughly 4 hours in a rotary kiln at about 1,800°
Phillip this is absoloutley cracking stuff top notch
Schazi why don’t you upload anymore
What is the purpose of calcium oxide and it's uses?
It is used in the manufacture of cement. So just about every building in the world uses it as the main ingredient of concrete
Thank you for responding can you revert calcium oxide back to calcium carbonate and can it be used for growing food?
Can l change chalk to calcium hydroxide?
Yes. All you have to do is heat it very strongly for a while and then add water.
Philip Russell thank you
Straight to the point!
saved my ass haha
Anyone else watching this for school?
No girls + go touch grass + you fell off + L + fatherless+ no parents
I agreee
Saaaaaaame
I know right
Actually no parents
2.05 Now we will take our piece of MARBLE. It was limestone a sec. ago. How fucked is this guy.