We had seen earlier that CO2 displaces air in a glass and the candle goes off. Let us see, what happens when candle burns in air. We will do a very simple experiment. For this we need a tall glass, a big and deep dish, some water and a mid-size candle.
Put candle at middle of, the dish and fill the dish with water. Now light the candle and cover the flame with the glass. Now the candle burns isolated from the air outside.
After sometime, we see the candle flame goes out and some water rises inside the glass. Mark the amount of air inside the glass with a marker pen. Use a measuring cup to find ratio of air that got consumed.
1. Why did the candle go out?
2. How much air was consumed?
When you open a bottle of coke, bubbles come out of the water. The gas that comes out is Carbon-di-oxide CO2. CO2 can be produced by adding some acid to lime stone, or some acid to soda/soda-bi-carb. When we burn coal or oil, then also we get Carbon-di-oxide. For our experiment, we shall use soda.
Take a spoon or two of soda in a large bottle and add some vinegar to it. Immediately lot of bobble will come out. Keep the bottle upright and in a place where there is not much wind. CO2 is heavier than air and will stay nicely in the bottle.
To check property of CO2, take two small candles light them in a glass. Now take the bottle of CO2 and tilt it like you will pour water in the glass. You will notice, the candle will extinguish as you pour CO2 in the glass.
CO2 being heavier than oxygen, displaces air/oxygen inside the glass and candle stops burning. This property is used in the fire extinguisher to stop simple fire. Also remember that same thing like candle can happen to you, if you sleep in a room without ventilator or any window.
Now let us do a test to find property of CO2. Pour some clear lime water in a test tube and then add CO2 in the test tube. Now close top of the tube with your thumb and shake the test tube. Lime water will turn turbid. This is second test. Add some Muriatic acid in the turbid lime water and it will again become clear.
Splitting water is easiest thing in the earth. All you need is a source of direct current a.k.a battery eliminator, some long wire, a plastic dish (deep) to keep water and couple of test tubes to collect what comes out of the split.
Tie the test tubes as shown with a cloth clip using a rubber band. Fill the tubes with water, add some salt to reduce the resistance. Shove open end of the cable inside test tube.
It may be a good idea to attach a gas carbon rod taken out from battery. This will protect the wire from erosion.
Once you do this, as I have done – you will notice bubbles coming out from end of the wire. These are Hydrogen and Oxygen.
What we did – is known as electrolysis a big word that means splitting by electricity.
Try electrolysis with concentrated salt water, let me know what did you notice.
Hydrogen – it is perhaps the simplest of the atoms and most abundant in universe. Consisting of just a proton and an electron it occupies the very first box of periodic table. Abundance of Hydrogen in universe is perhaps a good proof that our universe is young, with lot of energy to spend before it starts collapsing under its own weight.
To make hydrogen in your home you will need a pile of nails, about 50 gms
will do nicely. You will also need Hydrochloric Acid. Muriatic Acid sold to clean toilets etc. is a good source of HCl for our purpose.
For the experiment we shall use a glass bottle, with a two hole stopper. Put a glass tube that should go near the bottom and project out by at least 70mm out side. In the other hole insert a short tube. With the short tube attach a rubber tube about 50cm in length. Fill 1/5th of the bottle with nails. Then pour water till 1/3 of bottle. Then pour Muriatic acid to cover 2/3rd of the bottle. Quickly place the stopper on the bottle, taking care not to break the glass tube. Place the bottle on a tray. You will notice hydrogen bubbles coming out from the nails. Now take other end of the rubber pipe under a shallow through, and collect the gas in a water-filled test tube. Gas bubble will replace the water to fill the test tube.
You will notice Hydrogen is a colorless gas. If you take a lighted stick the gas will explode with a “pop” sound. Hydrogen explodes in presence of oxygen. As time goes the gas will have little oxygen mixed with it, then it will burn slowly with a bluish flame. If manage to blow a bubble with the gas, this will fly, as Hydrogen is lighter than air. Actually it the lightest of all elements.
Think of other things that you can do with hydrogen and write to me how your experiment go.
“A place for every thing
and every thing in it’s place.
That’s the way to sure success.”
There is nothing more convenient and peaceful than having a place on your own where you can do all your experiments without disturbance. For our work it does not take much to achieve that.
I use a simple rack for my work now. It has all my chemicals, labware and place for doing the work. On top, I keep the work. It has a test tube stand. A small plastic container to dispose chemicals, another small bottle to keep little distilled water to give final rinse to the lab ware. Rest keep changing on the need. I have a small pad of insulating material to keep hot bottles, glassware. Two spirit lamps for heating and glass works. I do take a little liberty of using few labware – it is there with me for last thiry years – two 100 ml beaker and two 250ml flask, besides couple of test tubes. These come handy as you can easily heat them and watch what’s going on inside. But these are not at all essential. Normal bottles would do just right.
If you have luxury of a big place available for your work, then you may spend a few buck on a Lab table. I had one such during my student days. Very convenient but takes lot of space.
Modern cramped flats where space is in big premium, you can probably get a wall unit made. The sketch given below will serve most requirement. You can extend the rack on top or bottom to store more items and chemicals. Drop down lid folds away to release space when it is not required. At the same time it is ideal to save unfinished work. If you have toddlers around in the house, it is essential that you keep all your chemical under lock and key.
Enough of talking about resource. Let’s get started with our first experiment. We shall see how a battery work and also salvage some raw material for our next experiment.
For this you need two exhausted zinc battery. Do not try this with alkaline cells or rechargeable ones – they contain some pretty corrosive chemical that we are not yet equipped to handle. You will require atleast two batteries to get material for our next experiments. That should not be a difficult task I suppose. Big UM3 size batteries are good, but AAA cells will also do.
If you have paper covered battery then your work is simple. But most batteries now have a metal leakproof jacket – it makes the task a bit difficult. Carefully with help of a plier remove the outer jacket. Inside you will find a grey colored tube – which should be heavily perforated by now by the corrosive chemical reaction that takes place inside the battery.
Carefully open the zinc casing from top. Inside you will find a dirty mixture of black powder and some paste. THese are manganese dioxide and ammonium chloride mixture. There will be some glue, and graphite powder. At the center there is a black rod – made of gas carbon. We need these rods in intact condition – take care not to break them.
Carefully disassemble the different parts on a old newspaper.scrape resedue out of zinc casing. Now pour the black mixture of MnO2 & NH4CL in a wide mouthed bottle. Pour about 70ml of water and mix it well to dissolve all soluble chemicals. If required pour a bit more. Decant and
then filter using funnel and filter paper. Old news paper makes excellent filter paper. The black resedue is primarily manganese di-oxide and solution has primarily ammonium chloride. Dry the solution in a shallow dish. You will get white powder of ammonium chloride. Some Zinc chloride and other impurities will also be present. Wash the zinc casing in tapwater.
Once you are done, save the four parts – Zinc, Manganese di-oxide, gas carbon rod and ammonium chloride in separate container. We shall use them in our later experiments.
Wash the zinc casing keep it aside in a wide mouth bottle.