Warm Chemistry

Warm Chemistry

After that long break, I would like to do a very simple experiment to start. This one is pretty common, most people probably know this experiment, but no one realized that there was more to it.

Things you’ll need: Yeast, hydrogen peroxide, a beaker, and a thermometer.

IMG_20140102_090435

  1. Pour 200 ml of hydrogen peroxide into a beaker.IMG_20140101_070545
  2. Insert the thermometer and look at the temperature.IMG_20140101_070613
  3. Add some yeast, not too little, stir it into the hydrogen peroxide.IMG_20140101_070705
  4. Keep waiting, the temperature will be high.IMG_20140101_070056

My temperature is about 63¬įC. That’s very hot. You saw the temperature change. The energy in the chemicals was converted to heat energy by the chemical change. You must know the yeast + H2O2 reaction, so I’m not going to explain it. This is also another way to create the elephant’s toothpaste demonstration.

IMG_20140101_070311

Thanks for taking your time to look at this post ūüôā

The Sediment of Lead (II) Nitrate

The Sediment of Lead (II) Nitrate

Today, I’m going to do a common experiment about the sediment of Lead (II) Nitrate. This is a very¬†quick demonstration¬†showing that two¬†solids¬†can¬†react¬†together. White¬†lead nitrate and white¬†potassium iodide¬†react to make yellow¬†lead iodide.

I added 5 grams of each chemical into 95ml  of water so I could have 5 % of each.

I pour 10ml of potassium iodide solution into each test tube. And poured 3ml of lead (II) nitrate into the first test tube. Poured 6ml of lead (II)nitrate into the second test tube. And poured 9ml of lead (II) nitrate into the third test tube.20170621_204221

As you could see on the picture the more lead (II) nitrate I add to the potassium iodide, more sediment increases in the test tube.

The demonstration might have more impact if the test tubes are opaque and the yellow product can be poured out and shown to the unsuspecting audience. Have a white background available.

Point out that for a reaction to occur, particles of the reactants must meet. This is much easier in solution (where the particles are free to move) than in the solid state.

The reaction is:

Pb(NO3)2(s) + 2KI(s) →  2KNO3(s) + PbI2(s)

All of these compounds are white except lead iodide, which is yellow.

Lead ethanoate can be substituted for lead nitrate, but the reaction is much slower.

The experiment  Diffusion in liquids is a class practical using the same compounds but as solutions.

We must first convert from a word equation to a symbol equation:

Lead (II) Nitrate + Potassium Iodide ‚Üí Lead (II) Iodide + Potassium Nitrate

The lead (II) ion is represented as¬†Pb2+, whilst the nitrate ion is¬†NO‚ąí3. To balance the charges, we require two nitrate ions per lead (II) ion, and so lead (II) nitrate is¬†Pb(NO3)2¬†.

The potassium ion is¬†K+¬†and the iodide ion is¬†I‚ąí. The two charges balance in a¬†1:1ratio, so potassium iodide is simply¬†KI.

In lead (II) iodide, the charges balance in a 1:2 ratio, so the formula is PbI2.

Finally, in potassium nitrate, the charges balance in another 1:1 ratio, giving a formula of KNO3 .

The symbol equation is as follows:

Pb(NO3)2+KI‚ÜíPbI2+KNO3

The most obvious change we must make, when balancing this equation, is to increase the number of nitrate ions on the right hand side of the equation. We can do this by placing a coefficient of 2 before the potassium nitrate:

Pb(NO3)2+KI‚ÜíPbI2+2KNO3

In doing this we have upset the balance of potassium ions on each side of the equation. Again, we can fix this: we must simply place another coefficient of 2, this time before the potassium iodide:

Pb(NO3)2+2KI‚ÜíPbI2+2KNO3

Checking over the equations once more, you will notice that we initially had 1 iodide ion on the right hand side, but 2 on the left. However, we already dealt with this in balancing our potassium ions. Now, our equation is balanced.

And that’s it! One last thing to add is that you may have noticed the irregularity in iodide ions rather than nitrate ions. In this case, you would have arrived at the same answer simply by working backwards.

Source: https://socratic.org/questions/how-do-you-write-the-the-reaction-of-lead-ii-nitrate-aq-with-sodium-iodide-aq-to

Changing Iron to Copper

Changing Iron to Copper

In this post, I’m going to show you how to change iron to copper in two easy steps.

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That’s not rust

 

Things you’ll need: copper (II) sulfate, a cup, a spoon, water, and nails or paper clips.

  1. Pour water into the cup.20170619_105233
  2. Put lots of copper sulfate into the cup. I put two spoons.20170618_200525
  3. Drop a paper clip or a nail into the solution.
  4. Wait for 24 hours, and take the paper clip/nail out of the cup. Be careful not to leave it too long in the cup, or else the metal will rust. (Wait for one day after you take the metal out of the solution).

    20170619_105333
    You can’t see the copper very well because of the shadow
   In Discorso, one of the last manuscripts written by Antonio Neri before his death, he reveals several transmutation recipes. One describes turning iron into copper; it is instructive because it uses common materials that we can identify and because the chemistry is now well understood.
Take some iron sheets and lay them in vitriol water, being immersed in that, they will rust. Scrape off this rust, which will be a red powder, melt it in a crucible, and you will have perfect copper. The same effect can be had from various waters that are naturally vitriolated, because they flow through mines of vitriol, such as those of a source some distance from Leiden, and another below the fortress of Smolnik, [now in Slovakia].
Vitriol is an acidic sulfate dissolved in water, it could be made in the laboratory, but it also occurred naturally around mining operations where sulfurous minerals were present. Alchemists knew this solution as “oil of vitriol” and “spirit of vitriol.” The mine that Neri references in Smolnik became famous for transmutation. As late as the eighteenth century, scientists and experimenters from around¬†Europe¬†made the pilgrimage to see the effect for themselves and tried to figure out what was happening. It may be a surprise to some readers, but following the above instructions will, in fact, produce copper just as Neri claimed. There is no deception or sleight of hand involved; the explanation is straightforward, but first, Neri treats us to a rare glimpse of his own reasoning on the subject:
Some estimate and not without reason, that this experiment, being used to prove the transmutation of metals, is not suitable for this purpose. They say that the vitriolated waters become such because they are already heavy with the corrosive spirits of sulfur, having passed through the copper or iron mine, these waters corrode copper in the same way aqua fortis corrodes silver. So that really the substance of the copper remains in the water, which attacks the surface of the iron, which always remains iron. However, if that were true then the iron would not get consumed, or if it were consumed it would mix with the substance of the corroded copper in the water, and if it were fused, it would remain a mixture of iron and copper. And yet in this experiment, all the iron is consumed; it is reduced by the vitriolated water into powder, […] which in the fusion is still pure copper, so there should remain no doubt that this is a true transmutation.
Given the state of chemistry at the time, Neri’s reasoning is clear and rational. The iron disappears and a copper coating materializes in its place. What better evidence of transmutation could one ask for?
The key to what was actually happening is in the criticism leveled by skeptics. It turns out that they were on the right track, but neither they nor Neri had the full picture. Today, we understand it as a simple ion exchange reaction; blue vitriol water is a transparent saturated solution of copper sulfate (CuSO4), in the presence of solid iron, the liquid dissolves the iron; copper from the vitriol is deposited in its place. The two metals, copper and iron, change places: the iron dissolves, forming green vitriol (FeSO4) and copper is expelled from the solution. The result is a reduction in the amount of the iron, which is replaced by a proportional deposit of pure copper.
On a physical level, this chemical reaction is no different today than it was in the seventeenth century. What¬†has¬†changed is our interpretation of the experiment. What Neri viewed as a transformation of iron into copper, we now see as an exchange. There is, however, a deeper lesson in all this. As an alchemist, Antonio Neri was not being delusional or dishonest; he was careful, observant and applied his knowledge as best he could. This is no different from the way science works today. Both then and now, to be successful in unraveling nature‚Äôs secrets, one must become accustomed to a very uncomfortable situation: In the past, careful reasoning by brilliant thinkers has led to utterly wrong conclusions. The fact that much of our world is a mystery is unsettling; that the very process we use to understand it can be so flawed is harder to accept. Even more difficult is that the faculty we all rely on for survival‚ÄĒour own wits‚ÄĒcan lead us so far astray.

Color Change Chemistry

Color Change Chemistry

Change a clear liquid pink, then back to clear again in this impressive experiment. It may seem like magic, but it’s actually the science of PH.

Things you’ll need: a beaker, a graduated cylinder, test tube holder, 3 test tubes, pipet, phenolphthalein, sodium carbonate, vinegar, and water.20170613_163519

  1. Fill the beaker halfway with water, and set the test tubes in the holder. I’ll refer to them in order as test tube 1, 2, and 3.20170613_163623
  2. Use a spoon to put a little bit of sodium carbonate in test tube 1.Use the pipet to add a few drops of water from the beaker. Swirl the test tube around to dissolve.20170613_164027
  3. In test tube 2, put two drops of phenolphthalein.20170613_164150
  4. Use the graduated cylinder to add 10 ml of vinegar to test tube 3.
  5. Carefully fill the first two test tubes with water from the beaker. Then, all at once, pour the contents of test tube 1 and 2  back into the beaker. The water will turn pink.20170613_164252
  6. Now pour the contents of test tube 3 into the beaker. the liquid will now be clear again. 

Phenolphthalein is a PH indicator that changes color when mixed with a base  (like sodium carbonate) but stays clear when mixed with an acid (like vinegar). In step 5, the phenolphthalein reacted to the basic sodium carbonate and turned the solution pink. To change it back to clear, you added acidic vinegar, neutralizing the basic sodium carbonate.

Learn more about phenolphthalein at this post: Invisible ink

Density Column

Density Column

Let’s start off with an easy experiment today. Create a colorful column with three liquids stacked on top of each other inside a test tube.

Things you’ll need: test tubes, pipet, food coloring, light or dark corn syrup, vegetable oil, and water.

  1. Pour about 3 ml of corn syrup into the test tube.20170608_164615
  2. Use a pipet to add 3 ml of water with food coloring (I use green). Make sure to drop the water on the side of the test tube.20170608_164940
  3. Do the same thing with vegetable oil but no water and food coloring.
  4. Observe the column you made. Which liquid is the least dense? Which is most dense? You could say that the liquid on the bottom has higher density. It means that the corn syrup has a high density. Medium density is water. And the vegetable oil has low density.

    20170608_165506
    My density column.
  5. What will happen if you add other liquids? Try adding apple juice, vinegar, soda, etc. You could also follow the column on the bottom.download

An object’s density is determined by comparing its mass to its volume. Consider a rock and a cork that are the same sizes; the rock is denser than the cork, because it has more mass in the same volume. This is due to the atomic structure of the elements, molecules, and componds¬†that make it up. The same is true for liquids. Although you added approximately the same volume of each liquid, they all had different densities, based on mass per volume. Water has a density of about 1.0 gram per ml of volume. Matter with higher density will sink in water; matter with lower density will float on top. Calculate the approximate density of other liquids using this formula: Density= Mass/Volume. Measure mass by calculating weight (how heavy it is). Weigh each liquid in grams (subtracting the weight of your container), the divide that number by the liquid’s volume (ml). The answer is density in grams per milliliter.

See also: The Floating Needle Experiment

Ice is Sticky

Ice is Sticky

I have an experiment that uses only ice.

Things you’ll need: 2 ice cubes.

  1. Press the flat sides of two ice cubes together.

    20170606_180056
    You probably know what I mean. I can’t do it because I’m holding the camera.
  2. Slowly count to thirty, then let go one of the ice cubes. What happened?

When you pushed the two ice cubes together, you created pressure between the two flat sides. Pressure melted the ice, making a thin layer of water in between. When you release the pressure, the water refroze, “gluing” the ice cubes together.

20170606_180042
It glued!

 

How to make a Lava Lamp

How to make a Lava Lamp

Well, you’re probably not interested in this post because you could just search the internet and find the same steps of this experiment. But the only thing good about this is that I will explain the science of this experiment. So let’s get started.

Things you’ll need: a flask, a beaker, Alka-Seltzer tablets (I used this on the Cold Chemistry¬†experiment), food coloring, vegetable oil, and water.20170529_152127

  1. Fill the flask to the 200 ml line with vegetable oil.20170529_152205
  2. In a beaker, stir several drops of food coloring into 100 ml water. Fill the rest of the flask with the colored water from the beaker, adding about 50 ml. The water will slowly sink to the bottom of the flask.
  3. Break an Alka-Seltzer tablet into a few small pieces and drop them in the flask one at a time.20170529_152458
  4. Watch your lava lamp erupt into activity! As the reaction slows down, you could add more Alka-Seltzer pieces.20170529_15252020170529_15252420170529_152526

Oil and water have different densities. Oil is a non-polar liquid while water is a polar one. Polarity refers to the way molecules connect with each other – what kinds of molecular bonds they have. Polar molecules only bond¬†with other polar molecules. This is why oil doesn’t mix with water. Real lava lamps use a polar and non-polar liquid just like this one did. However, the densities of liquids are much closer together than oil and water. The denser liquid sinks to the bottom, but the lava lamp light heats it up until it expands and becomes less dense, causing it to rise. As it gets farther from the light, it cools down, sinks, and starts over.

Instead of using a light, in my homemade lava lamp I used Alka-Seltzer, which reacts with the water to produce carbon dioxide gas bubbles. These stick to the water droplets. The water/gas combo is less dense than the oil, so it rises to the top of the flask. At the top, the gas bubbles pop and escape into the air, allowing the dense water to sink back to the bottom again. When enough carbon dioxide gas escaped, the reaction slowed. Add more Alka-Seltzer tablets to keep the reaction going.

Learn more about densities at my The Floating Needle experiment.

Cold Chemistry

Cold Chemistry

Endothermic chemical reaction use up heat energy, which means the end result is cool to the touch. Use Alka-Seltzer to see this reaction for yourself!

Things you’ll need: A beaker, a thermometer, an Alka-Seltzer tablet, ice, and water.20170526_144541

  1. Fill the beaker with ice. Add enough water to cover the ice fully.20170526_144708
  2. Put the thermometer in the beaker and read the temperature of the ice water after about one minute when the temperature is steady. Mine is 11¬įC ¬†(51¬įF).20170526_144807
  3. Add the Alka-Seltzer tablet to the beaker and read the thermometer. Mine is 6¬įC ¬†(42¬įF)20170526_144929

Melting ice absorbs heat and cools water until the ice water reaches the freezing point (0¬įC=32¬įF). Mixing Alka-Seltzer with the cold water was an endothermic reaction, meaning it used heat. An Alka-Seltzer tablet contains two main ingredients: sodium bicarbonate and citric acid. In the ice water, they reacted to form sodium citrate and carbon dioxide, which removed energy and further dropped the solution temperature. The Alka-Seltzer solution became super-cooled by the endothermic reaction.

Slimes and States of Matter

How to make Slime in Three Steps (and states of matter)

I’ll show you how to make slime in the easiest way. It’s going to be messy but it’s worth to try.

Things you’ll need: Borax, water, a spoon, school glue, and two cups.

  1. Add one teaspoon of borax to 75ml of water into the cup and stir until all of the borax is dissolved. Add a few drops of food coloring if you like.
  2. Pour one teaspoon of water and one teaspoon of school glue. Use the spoon to mix the water and glue.
  3. Add about 30 drops of the solution from step 1. and stir. If necessary, add a few more drops of the solution and stir until all of the glue and water is thick and not sticky.20170521_093721

Your slime is very similar to “Silly Putty” or ¬†“GAK”. Silly Putty was accidently¬†created 50 years ago by an engineer trying to develop a ¬†synthetic rubber from silicone oil and boric acid (a chemical relative to borax).

When you added the borax solution to the glue mixture, you could see how they came together to form a glob. The borax solution links or bonds parts of the glue together into tiny structures that are atomic or molecular nets that can trap and hold water.

A solid, such as ice, is rigid or stiff and has a definite shape and volume. The parts are held together, and cannot move past one another. But, if ice is melted, it forms liquid water. A liquid has a definite amount of space or volume, but its parts can move easily and a liquid will flow and take the shape of its container.

The slime is a substance between a solid and a liquid like clay. They call that oobleck. If you pull the slime apart very quickly, it will break like a stick which is a solid. But you can put the slime back together again because the parts can flow like a liquid.

To learn more about slimes and gels go and buy this kit at Amazon.com.41mRyuITCsL

Invisible ink

Invisible ink

We know that phenolphthalein will turn pink if you drip 2-3 drops into a chemical that is base. That gave me an idea of how to make invisible ink.

Things you’ll need: phenolphthalein¬†solution, white paper, Q-tip, and ammonia-based glass cleaner (like Windex)

  1. Put a few drops of phenolphthalein onto a Q-tip. Use the Q-tip as your pen to write a simple message (like “hello”).
  2. Let the paper dry. You cannot see the message.
  3. Once the paper is dry, spray it with a few squirts of glass cleaner. The message will appear again in purple.20170519_165110

Phenolphthalein is a PH indicator that is pink in the presence of bases. Since the window cleaner is a base, it reacted with your phenolphthalein writing to change color and appear visible. Look at this picture below.

 

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In the first test tube is vinegar. In the second test tube is water. In the last test tube is borax. Each test tube has 2 drops of phenolphthalein.

 

 

A Water Pressure Experiment

Water Pressure Experiment

This experiment is good to demonstrate water pressure.

Things you’ll need: a water bottle with water, modeling clay, two straws, and scissors.

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  1. Use the scissors to cut one straw to be shorter than the other.
  2. Use the modeling clay to hold the straws together as shown in the picture.20170405_135023
  3. Place the straw and the modeling clay on the bottle as shown in the picture. (Warning: don’t let one of the straws touch the water and don’t let any air come out from the bottle). Seal the clay tightly and close all the holes.20170405_135207
  4. Blow the straw that didn’t touch the water and the water will come out from the other straw.

    Click on image to get bigger

Water pressure is a measure of the force that gets the water through our mains and into your pipes. It is measured in ‘bars’ – one bar is the force needed to raise water to a height of 10 meters.¬†0.1 bar equivalent to approximately 1.45 pa of pressure. With low-pressure water systems, you‚Äôll want to measure your water pressure precisely to find a tap or shower that will give you optimum flow.

20170405_135450 copy The red arrows are water pressure.

The Floating Needle

The Floating Needle

What will happen if you put a needle in a cup of water? It would sink. But you can do it if you use density.

Things you’ll need: a needle, a sharp pencil, A strip of paper that is a little bigger than the needle, a cup, and water.

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  1. Fill water into the cup
  2. Put the piece of paper on the water.20170328_112911
  3. Put a needle on the piece of paper.20170328_112925
  4. Use the sharp point of the pencil to push the paper down to make it sink.20170328_112956
  5. Now, you should have a floating needle.

    Click on picture to make it bigger

A material’s density is defined as its mass per unit volume. It is, essentially, a measurement of how tightly matter is crammed together. The principle of density was discovered by the Greek scientist Archimedes.¬†To calculate the density (usually represented by the Greek letter “ŌĀ”) of an object, take the mass (m) and divide by the volume (v):¬†ŌĀ = m / v

The density of water is about 1 gram per cubic centimeter (62 lb/cu ft): this relationship was originally used to define the gram. The density varies with temperature, but not linearly: as the temperature increases, the density rises to a peak at 3.98 ¬įC (39.16 ¬įF) and then decrease. This unusual negative thermal expansion below 4 ¬įC (39 ¬įF) is also observed in molten silica. Regular, hexagonal ice is also less dense than liquid water‚ÄĒupon freezing, the density of water decreases by about 9%.

The Blue Rose Experiment

The Blue Rose Experiment 

(March 1, 2016)

Introduction:

In this Blue Rose Experiment, I was trying to confirm what other researchers found: that food dye added to water in a vase will cause the rose to change color. My hypothesis was that adding blue food coloring to water into the vase would cause a white rose to turn blue.

Materials:

2 white cut roses (I got the rose from my mother’s garden),

DanPickingRose

  • 2 cups
  • Blue food coloring
  • Water
  • Pure refined sugar

1. Add 250ml of water into the first cup, then add 250ml of water into the second cup and then add 1ml of blue food coloring.

2. Add a pinch of pure refined sugar about .125cc into the two cups and place the stem of the roses into the cup.

3. Wait for 2 or 3 days and record what happened. If the rose in the first cup turns blue that means the sugar makes the rose blue.

Results:                        Control                          |                         Experimental

                Day 1    

                          controlday1                    controlday1    

              Day 2

                    controlday2              testday2

The control is not blue and that means the sugar didn’t make the rose blue. The rose in the blue dye vase turned blue on the second day.

Conclusion: Blue dye caused the white rose to become blue because the dye was absorbed through the stem.

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