Simple-Science - Simple Experiments (Digest # 17)

Today in the issue:

• the simplest electric motor on the battery;
• balloon and -170 ° C;
• black sugar;
• free fall;
• shell dissolving;
• fuel for hydrogen cars.

Attention:

Some experiences may be hazardous to health. When they are carried out, it is imperative to observe safety precautions.

See below for 6 videos with explanations.
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The simplest electric motor on the battery

Why the wire is spinning

Rotation occurs because an electric charge occurs in the wire. And this is nothing more than the ordered movement of charged particles. Each of them is affected by a magnetic field, which rejects the direction of their movement. This deviation is called the Lorentz force. Physical language is the force with which an electromagnetic or magnetic field acts on a point-charged particle. A special case of the Lorentz force is the situation when the magnetic field is directed perpendicular to the velocity vector. In this case, the force becomes centripetal. more

Balloon and -170 ° C

Why air in a ball is compressed at -170 ° C

The laws of thermodynamics tell us that the pressure, volume and temperature of a gas are dependent on each other. And at constant pressure (such a process is called isobaric) the dependence is as follows:

That is, the dependence is direct. The greater the volume, the greater the temperature. The lower the temperature, the smaller the volume, etc.
This happens because of a change in the distance between the molecules, which is a consequence of a change in the kinetic energy of the particles due to external influence. more

Black sugar

Why it happens

How does this happen, and why does a black solid porous object form from white sugar and clear liquid?
Sucrose is a disaccharide with the formula C12H22O11. Whence it is seen that the ratio of H and O atoms is the same as that of water — two hydrogen per oxygen. Concentrated sulfuric acid absorbs water from sugar, and the remaining carbon is released in the form of coal.
Like most reactions of sulfuric acid, this reaction is exothermic, that is, runs with the release of heat. Therefore, the water evaporates, and only the dry solid residue remains.

2122211 + 224 = 23 + 2 + + 22 + 242

The gases produced in the process churn the carbon and it becomes porous. more

Free fall

Why the ball falls into the trap

Free fall is a rectilinear motion. Its direction is always perpendicular to the plane of the surface of the object of attraction. In this case, it is the planet Earth. And the bar, in particular. Because it lies parallel to the surface of the Earth.

So, our ball, when the support is removed from under it, under the action of gravity begins to move in a straight line, perpendicular to the lying bar. At this time, each point of the strip moves in a circle and lands on the surface of the plank with an offset. Having calculated the shift empirically, we place our “trap” on this place. more

Dilution of shells in acid

Why are shells dissolve in acid

The chemical composition of the shells in its natural form is as follows: 63-94% CaCO3 (calcium carbonate), 2-25% SiO2 (sand) and other inclusions, which are less than 2%. They are not soluble in water - it is a fact - they lived there. What about hydrochloric acid?

Sand with hydrochloric acid does not react. So the main reaction is calcium carbonate. Active chlorine displaces the acidic residue in the calcium salt to form calcium chloride and unstable carbonic acid, which decomposes into water and carbon dioxide. The chemical reaction is as follows:

CaCO3 + HCl CaCl2 + H2O + CO2

The reaction is exothermic, like most of the reactions of strong acids, so that proceeds quite rapidly. The formed calcium chloride — a colorless salt in the form of crystals — is soluble in water, and therefore not visible. The insoluble particles remaining in the solution are sand and other inclusions. As we see, there are not so many of them. more

Fuel for hydrogen cars

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