BUILD A DANIELL CELL PubliosValesios 2010-11-04 | Good morning, in this video I'll show you how to build a Daniell cell. The experience is essentially done to illustrate how a galvanic cell works and not to produce a cheap source of electricity, but it's just meant to explore the science. Daniell cell was built for the first time in 1836 by the english scientist and chemist John Fredric Daniell and is able to produce about 1 volt in power per cell. Let's get started. Take two small glass containers and fill them with distilled water. In the left one put a little more water than in the right one. Now add on the left about 19 grams of zinc sulphate and in the other one about 34 grams of copper sulphate penthaidrate. Mix until the salts are completewly dissolved. Now on the left immerse a zinc foil and on the right a copper one. Connect the beakers with a salt bridge made of paper soaked in a solution of water and table-salt: the ions will pass from the solution to another one, but solutions won't mix togheter at all. Now connect your multimeter: a source of 1,06 volts is produced. What happens is a redox reaction, at the same time oxidation and reduction. On the left(anodic cell) oxidation occurs: zinc metal atoms lose each two electrons and become a Zn2+ ion and two electrons (2e-). Electrons pass thanks to the apparatus to copper sulphate solution on the right. On that side(cathodic cell) reduction occurs: the electrons react with copper ions (Cu2+) and form copper metal that increases the copper foil. This is the reaction: Cu2+ + 2e --- Cu. The complete reaction (sintesis of the first and the second one is the following) : Zn + Cu2+ --- Zn2+ + Cu. The molar concentrations used is 1M. Thanks for watching, plaese subscribe rate and comment too.
COPPER (II) NITRATE- THE COMPLETE GUIDE PubliosValesios 2012-11-19 | Hello boys and girls, but especially girls, it 's Publios Valesios (Publius Valerius). It's a long time that I Don't publish any video but watching you tube I saw that there's not pratically anything for an extremely basic synthesis that is to say copper(II) nitrate.Well, many you tubers produce it but they do not show how to isolate the compound, how to store it... so this is an almost complete guide about it.
CALCIUM PHOSPHATE FROM BONES PubliosValesios 2011-12-15 | Hey! Before starting I whould like to excuse with my subscribers if recently I didn't publish any video but I was very busy. Now, today I will show you a very strange experiment, purificating calcium phosphate, that is to say tricalcium phosphate from animal bones
FLAME TESTS PubliosValesios 2011-09-10 | Hey you, today I'm back again with a cool and simple experiment. I'm speaking about flame test, a common analitical test ti detect the presence of different ions in a chemical compound. Atoms of th sample(usually metallic ions) heated in direct contact with flame are excited and give off flames of different colours that distinguish one element from another one. Now, to start you need a burner, about 50 ml of 15% HCl acid, salts such as alkali metals ones but also copper and lead will work. It is also required some nickel-chromium wire. To perform the procedure soak the end of the wire in hydrochloric acid, then into the salt and bring your wire near the burner flame:it will turn into another colour depending on the salt you used. To show you better the colour I will turn off the light. And here we go. Na,Li,Ca,B,Cu,Pb,-NH4 Obiviously I didn't show you all tests flames because I miss many elements. So feel free to experiment. That's all folks, greetings.
LEAD IODIDE SYNTHESIS PubliosValesios 2011-09-09 | Hi guys and ladies and welcome back, today I suggest you a classic experiment using lead nitrate prepared in our previous video that is to say lead(II) iodide, a nice yellow but unfortunately almost unuseful salt. Warning. Lead and its salts are extremely toxic and polluant. Wear gloves while handling with it and do not contaminate things and people. To start I'm adding 3.3 grams of lead nitrate on the left container while on the other one 3,3 grams of potassium iodide. Then we solve them into water and mix til the complete dissolution. Once it's done add the lead solution to the other one. A precipitate of lead iodide forms instantly. Here the reaction. PbNO3 + 2KI--- PbI2 + 2KNO3. Now philtrate and let it dry. And even if it seems nice and you whould like to eat it remember :you could do that only one time.(You whould die). Greetings.
LEAD NITRATE PREPARATION PubliosValesios 2011-08-11 | Hi guys, today I'm back to show you how to prepare some lead nitrate, an useful chemical compound that we will use in next experiments. Warning. During this experiment toxic fumes of nitrogen oxides are produced. Work outside or in a fumehood. Lead and its salts are extremely toxic and dangerous for the environment. Wear gloves, goggles and a proper safety equipment and do not contaminate things and people. Nitric acid is corrosive, watch you while handling with it. After this warning we can start. Put 71 grams of lead metal in a beaker and add some distilled water. I'm using lead balls but I suggest you to use lead ingots if you've got. Now add 100 grams of 65% nitric acid. Then heat the beaker until it arrives to 70-90 degrees Celsius with an hotplate and a thermometer. If you haven't got them you can use a pan filled with water on a gas burner withouth making the solution within the glass beaker arrive to boil. Slowly the solution turns to orange yellow because of the nitrogen oxides dissolved into it. After 40-60 minutes the solution turns unfortunately to black because small pieces of lead metal come off the little balls and make muddy everything.This is the chemical reaction: 3Pb+8HNO33Pb(NO3)2+2NO+4H2O Lead metal reacts with nitric acid to give lead nitrate, nitrose dioxide and water. After one hour-one hour and half the reaction increases and sometimes becomes violent. For that reason I've been obliged to change my first beaker with another one larger. When the reaction is over (after almost 2 hours) add some water to solve all the nitrate and philtrate. Here we're adding some water. After I mixed the solution has turned to yellow. Now I'm filtrating one or two times. After let the solution evaporate. Sometimes it takes several days. The final result is almost 100 grams of lead nitrate. Now, it should be white but it is light yellow probably because in my lead was present a small quantity of iron. However our lead nitrate is still good for home lab chemistry. Thanks for watching, see you soon.
TARTARIC ACID PREPARATION PubliosValesios 2011-06-05 | Hi guys. I'm back today with a procedure able to make you get relatively pure tartaric acid from potassium bitartrate sold in groceries. Depending on where you live it will be cheaper buying direclty tartaric acid than doing it, but this video as you know is meant just to explore the science. Warning, tartaric is irritating and sulfuric acid is highly corrosive. Wear gloves and a proper lab equipment during the experiment. Let's get started. Add 37,5 grams of potassium bitrartrate to 250 ml of hot water and try to solve as much as you can (potassium bitartrate is non so soluble). While keeping the temperature high but under 100 degrees celsius, add carefully 15 grams of calcium carbonate in powder. Bitartrate becomes calcium tartrate and neutral potassium tartrate. There is also a release of CO2. This is the reaction: CaCO3+ C4H5KO6------ C4H4CaO6 + C4H4K2O6 + CO2 + H2O Then we add 15 grams of calcium chloride solved into hot water. The neutral potassium tartrate is changed into calcium tartrate thanks to a double echange reaction: CaCl2 + C4H4K2O6----- 2 CH4CaO6 + 2KCl By philtration you collect the calcium tartrate insoluble into water. Then you will put it into a beaker that you will put in a pan with boiling water, and you won't put the beaker directly on the hotplate. Sothat add 25 ml of 96% H2SO4 solved in 75 ml of water. After thirty minutes calcium tartrate is decomposed into pure tartaric acid and on the bottom calcium sulfate settles. This is the reaction: H2SO4 + C4H4CaO6-----CaSO4 + C4H6O6. Filtrate while is still hot. Wash many times the sulfate that contains still quantities of tartaric acid and add the washing water to the philtrate. Let it evaporates for 6-10 days, than you will collect large crystals of tartaric acid. Tartaric acid is an useful reagent to make tartrates. Thanks for watching
STARCH EXTRACTION PubliosValesios 2011-05-04 | Hi guys, today I prepared a video about a very simple extraction that is to say starch from cooking potatoes and its relative test with commercial tincture of iodine. Before starting just two words about starch. it is a natural polymer present in rice, ceral, potatoes and it is a source of energy for living creatures. It is composed of two different polymers: amylose 20% and amilopecten 80 %. Both of them are chains composed of unities of alpha glucose. Here we can see a simplified picture of starch molecule which is much more complex. Now let's get started. The procedure is so simple that also a child could do that without problems. Simply take a one hundred grams potato and peel it. Now simple grate it. Once it's done put it to a beaker with two hundred millimitres of hot water. Now mix for about one-two minutes. Then filtrate with a cook filter to another container. With the lasting part that is to say the grated potato you can repeat the operation several times adding water and mixing, and filtrating again but this is optional. After 5-10 minutes starch, insoluble into water will precipitate out. Here we can see the white precipitate, pure starch. Simply moving the liquid phase to another beaker you will isolate the product. Let it dry at room temperature. Here we can see starch and it appears white, a little bit creamy but after essiccation it will be cristalline. Now, to test it is really starch and not magic powder, we will use some tincture of iodine ( a mix of ethanol, water, potassium iodide and elemental iodine). To test it put some starch into a test tube with some water and shake. After add the tincture of iodine that you can diluite with water or not. However, the solution will become dark blue coloured. What happens is that iodine ions (I3- ) combine to amilose and they make the compound take up this colour. My greetings, see you on the next experiment.
MAKING SOAP THANKS TO ESTERIFICATION PubliosValesios 2011-03-11 | Hello you. How many times they told you that you smell bad or more gently that from your t- shirt doesn't come exaclty a spring's fragrance? This video will make you able to silence them or better to take revenge by giving to them nice bars of soap. Yes, in this video I'll make some soap thanks to a simple chemical reaction (esterification). Let's start with 250 g of seeds oil put into a large beaker, while in the other one you are going to put 32 g of sodium hydroxide solved into 75 g of water. Now add the hydroxide solution to oil: the reaction will starti immediately making the oil dull. You have to help the process by mixing with a glass rod. But since we want to perform the reaction as faster as possible we'll be using an electric whip. I'm transferring it to a stainless steel pan for space reasons. Now let's stir every thing and see what happens. During the reaction it happens that a triglyceride composed of glycerine and a fatty acid (in this case linoleic acid present in seeds oil) reacts with three molecules of sodium hydroxide to give three molecules of a sodium fatty acid(in this case sodium linolate) and a molecule of pure glycerine, which is an alcool. When you read R you have to imagine a long carbon chain, in this case with two double bonds in 6-7 and in 9-10 position. Now you have to stir for about 20 minutes and at the end you should get a yellow product, a little bit dense. Now transfer everything to a beaker. You can perfume your soap with perfumed oil: I'm using orange oil, but this is optional. At the end put the soap still liquid into other beakers greased with oil. It is important to do that because without doing that you won't be able to extract it without breaking the glass. Wait for two days and after extract the bars of soap. Make it dry for two three weeks and at the end it will be ready. Watch you: probably you don0t want to wait for so long but remember: using the soap without waiting for all the tima that i suggested could cause burns. And now, you can have a wash with natural soap, extremely ecological and self made. This is just a way to operate, obiviously feel free to make different kinds of soap: there's a big choice. And so, nobody will say anymore: wash yourself. Thanks for watching.
GET COPPER (II) FLUORIDE. PubliosValesios 2011-02-06 | Hello you tube watchers, today I'm going to make copper(II) fluoride. Surfing the net I discovered there's pratically nothing about fluorides if we exclude videos about the dangers of using them in brushing your teeth so for that reason I decided to post something. Cupric fluoride synthesis available at home is able to make just an hydrated salt since the anidrous is more difficult to get. Warning, hydrofluoric acid is highly corrosive for skin and can cause burns, plaese wear gloves during the experience and work outside or in a fumehood. Let's get started. Fill a plastic container with 25 ml of 12% hydrofluoric acid. Do not use glass beakers since HF attacks it and it will corrode your apparatus. Now put about 15 grams of copper hydroxide into the container. If you haven't got it you can get it by mixing two solutions of copper sulphate and sodium hydroxide kept cold, like showed in another of my videos. Then mix: the solution turns from the deep blue colour of the hydroxide to the greenish one of the fluoride. By evaporating it on a burner you will be able to get the salt divided from water. Now, the fluoride got by using the hydroxide contains small impurities of cupric oxide. You can solve the problem using copper carbonate instead of the hydroxide to get a purer stuff. On the photo on the left you see the fluoride obtained by using hydroxide, while on the right the salt got using carbonate. If you have got a different way to operate better than mine don't exitate to contact me. So feel free to experiment. Thanks for watching, plaese subscribe, rate and comment.
CUPRAMMONIUM RAYON SYNTHESIS PubliosValesios 2010-12-22 | Good morning everybody, today we're going to synthetize cuprammonium rayon by chemicals available at home without problems. The experience it's just meant to illustrate how a polimerization process works and to explore the science so don't expect to get a fine or useful product. rayon is a manufactured regenerated cellulose fiber. Since it's produced from natural occurring polymers it is neither synthetic fiber nor a natural one: it is a semi-synthetic fiber. There are three of more methods to make it: but just one is available at home: cuprammonium rayon. Warning: sodium hydroxide is corrosive, ammonia's fumes are toxic, plaese wear gloves and work outside or in a fumehood. Let's start with two solutions of very cold distilled water, about 60 ml for each beaker. In the first one on the left put 8 grams of copper sulphate pentahydrate, in the second one on the right 4 grams of anidrous sodium hydroxide. Now mix til they are completely dissolved. Working fast add the sulphate solution to the other one: a precipitate of copper hydroxide forms instantly. This is the reaction: CuSO4 + 2NaOH ---- Cu(OH)2 + Na2SO4 After filtrate with a paper filter the hydroxide and put it into a larger beaker full of ice. Infact it is important to keep copper hydroxide cold for the next step or it will decompose into copper oxide unuseful for this reaction. After add about 50 ml of 30 % concentrated ammonia. Copper hydroxide solves into ammonia to form the deep blue coloured complex called schweitzer's reagent [Cu(NH3)4](OH)2. This complex is able to solve cellulose. After this passage put some paper into the cuprammonium complex and the mix. The blue liquid will become something like a jelly: it means it's ready for the next step. Into a largew container now put a solution of 5-10 % sulfuric acid solved into water. then with a syringe without needle take a part of the jelly and make it forms wires upon the acid bath: rayon forms instantly. If you wanna get more fine wires put the needle to the syringe after you charged it, or it will block. as you can see rayon appears like small blue larvas. It's pretty cool to touch it and to play with it. Wires are platic and soft and they break very easely. wash rayon fibers obtained with water: the colour will pass from blue to white. Let it dry and now you have cuprammonium rayon. That's all folks, thanks for watching, plaese subscribe rate and comment if you liked.
MAKE IODOFORM WITH HALOFORM REACTION PubliosValesios 2010-11-13 | Good morning, in this video we will obtain iodoform (CHI3) thanks to haloform reaction. The procedure is extremely easy. Put in a beaker of 250 ml 12 grams of potassium iodide (KI) and solve into one hundred millimetres of water. Mix and then add 4 ml of acetone (CH3-CO-CH3). After just add one hundred and fifty millimetres of bleach (a solution of 5% of sodium hypochlorate): molecular iodine forms instantly but going on with the operation and mixing it becomes iodoform, a nice yellow coloured jelly that precipitates out. After a little bit the compound will precipitate and you will be able to filtrate the particles that won't precipitate immediately, but this is optional. Now you can see the product. Let it dry and now you have iodoform. Now some theory. The reaction we performed is called haloform reaction and it was used for the first time in 1822 dy Serullas. The semplified reaction is the following one : R-CO-CH3 ----- (X2 e BASE) R-COO- + CHX3. So the reaction occurs between a alcool, ketone (in this case acetone that is a ketone) with an halogen ( we used iodine under a salt of iodine) in basic environment (in this case bleach). The product is a carboxilate ion and CHX3 (in this case iodoform), Here is written every passage of the reaction. In the fisrt step the halogen disproportionates in the presence of hydroxide to give the halide and hypohalite. If like i is present a ketone and not an alcool the following part of the reaction follows these three steps: Ketone sobstitutes three atoms of hydrogen from CH3 group with three atoms of the halogen forming halometilketone and OH- ions. 1) R-CO-CH3 + 3OX- ---- R-CO-CX3 + 3OH- After halometilketone becomes a carboxilic acid by exchanging the halogen with a OH- ion 2) R-CO-CX3 + OH- ---- RCOOH + -CX3 In the last part the molecule undergoes a nucleophilic acyl substitution by hydroxide, with −CX3 being the leaving group stabilized by three electron-withdrawing groups. The −CX3 anion abstracts a proton from either the carboxylic acid formed, or the solvent, and forms the haloform. 3) RCOOH + -CX3 ---- RCOO- + CHX3 What about iodoform uses? It's used especially like disinfectant and in organic chemistry for iodoform test that makes possible to find if a CH3 group is present in a certain compound. That's all folks, plaese subscribe rate and comment.
MAKE WEAK NITRIC ACID PubliosValesios 2010-08-17 | In this video I will show you how to make weak nitric acid. Good morning. Warning: the experiment produces large quantities of toxic gases and uses very corrosive acids. All procedure must be performed in a fumehood and all apparatus must be glass to withstand the acids. As you all know nitric acid is a very useful acid able to dissolve copper, silver and many other metals. In this video I will show you a simple way to make it. Let's start with about eighty grams of a nitrate salt. I'm using potassium nitrate but you can also use another nitrate salt like ammonium nitrate. Put the salt in a glass container then add about 25 ml of water and try to dissolve as much as you can. Then add about 16 grams of copper or more. Now take a larger container then fill it with 25 ml of weak and cold hydrogen peroxide. After put the first container in the second one and carefully add 50 ml of 30 % hydrochloric acid. Now place a container large enough to fit over the small container but small enough to fit inside the other container. The reaction lastes thirthy minutes or more so that I'll skip over that part. However the solution turns first to yellow, to green and and at the end to black.After a little bit you will be able to see the highly toxic nitrogen dioxide that has got a red-orange colour. Since it's produced because it's heavier than air it's forced to flow into a larger container and reacts with the hydrogen peroxide to form the acid. The process it's not so efficient but it works. Allright, take out both inner beakers: a red cloudy of the gas is let free so be careful. Now pour out the acid: it's a pale green because it's contaminated with the original solution and bvery beak but somewhat useable. To test it add some to a test tube and after put a small piece of copper: it's bubbling so nitric acid it's present. After a little bit the solution turns to a pale blue due to the presence of copper nitrate. Here you can see a lead nitrate solution made by adding the acid produced to a piece of lead: because of impurity it apperas yellow coloured and a white powder of tin salt is present. (Tin infact is normally used in small amounts in common lead items). That's all folks, thanks for watching, plaese subscribe rate and comment too.
MAKING A COPPER HYDROXIDE PRECIPITATE.wmv PubliosValesios 2010-06-19 | Good morning, in this video I'm going to show you how to make copper(II) hydroxide in a very simple way. Warning, sodium hydroxide which we will use is corrosive and copper hydroxide is irritant, please wear gloves during the experiment. Te raction we will perform is the following: two molecule of sodium hydroxide plus copper sulphate pentahydrate produce sodium sulphate and copper two hydroxide. Now let's get started. Put some water in a beaker or in a glass container. I'm using distilled water. Now add about eight grams of copper suphate penthydrate. Mix until they will be completely dissolved. Now take a larger container and do the same thing, adding water and four grams of sodium hydroxide. Solve them like you've already done for the copper solution, Now with a siringe take a little bit of water from the light blue solution and add it to the second one. A blue precipitate of copper (II) hydroxide is forming istantly: infact while the sodium sulphate which forms is soluble into water the copper hydroxide is not soluble at all. If you want to separate the two compounds it is necessary to philtrate the solution. And now you have copper(II) hydroxide. As you can see it is a pale blue gelatinous solid and it's used especially in organic chemistry, like fungicide and occasionally as ceramic colorant. Plaese suscribe, rate and comment.
LITHIUM BURNING FLAME PubliosValesios 2010-03-06 | Lithium burning gives off a striking crimson colour but when it burns strongly the flame becomes a brilliant silver.
