COLLOID
There
is this daily life, often we encounter some products that are a mixture of some
substances, but they can be mixed evenly or homogeneously. For example, when
the mother makes milk for siblings, powder or milk flour mixed evenly with hot
water. Such products are colloidal systems.
Colloids
are a mixture of heterogeneous substances between two or more substances in
which the colloidal particles of matter are spread evenly in another substance.
The size of colloidal particles ranges from 1-100 nm. The size in question can
be the diameter, length, width, or thickness of a particle. Another example of
a colloidal system is the ink, which consists of color powders (solid) with
liquid (water). In addition to ink, there are still many other colloidal
systems, such as mayonnaise, hairspray, and jelly.
Choloid
Properties
• Tyndall effect
The
Tyndall effect is a symptom of scattering of light beam by colloidal particles.
This is because the size of the colloidal molecule is quite large. This tyndall
effect was discovered by John Tyndall, a British physicist. Therefore it is
called the tyndall effect.
The
tyndall effect is the effect that occurs when a solution is exposed to light.
When the true solution is illuminated with light, the solution will not scatter
light, whereas in the colloidal system, the light will be scattered. It happens
because the colloidal particles have relatively large particles to be able to
scatter the rays. In contrast, in the true solution, the particles are
relatively small so that the scattering occurs only slightly and is very
difficult to observe.
• Brownian motion
Brownian
motion is the movement of colloidal particles that always move straight but not
erratic (random or irregular motion). If we observe colloids under an ultra
microscope, then we will see that the particles will move to form zigzags. This
zigzag movement is called Brownian motion. The particles of a substance are
constantly moving.
The
movement may be random as in liquids and gases, or simply vibrate in places
such as solids. For colloids with a liquid or gas dispersing medium, the
movement of particles will result in collisions with the colloidal particles
themselves. The collision took place from all directions. Because the particle
size is small enough, the collisions that occur tend to be unbalanced. So there
is a resultant collision that causes changes in the direction of motion of
particles resulting in the motion of zigzag or Brownian motion. The smaller the
size of colloidal particles, the faster Brownian motion occurs. Similarly, the
larger the size of colloidal particles, the slower the Brownian motion occurs.
This explains why Brownian motion is difficult to observe in solution and is
not found in solids (suspension). Brownian motion is also affected by
temperature. The higher the temperature of the colloidal system, the greater
the kinetic energy of the dispersed medium particles. As a result, Brown's
motion of the dispersed phase particles is accelerating. Similarly, the lower
the temperature of the colloidal system, the more slow the Brownian motion.
• Absorption
Absorption
is the absorption of particles or ions or other compounds on the surface of
colloidal particles caused by the surface area of the particles.
Okay, please watch my video on :
https://www.youtube.com/watch?v=EgZh2Zt3NF0
can you explain about coloid proportion
BalasHapusCHOLOID PROPERTIES
Hapus• Tyndall effect
The Tyndall effect is a symptom of scattering of light beam (light) by colloidal particles. This is because the size of the colloidal molecule is quite large. This tyndall effect was discovered by John Tyndall (one thousand eight hundred and twenty until one thousand eight hundred and ninety-three), a British physicist. Therefore it is called the tyndall effect.
The tyndall effect is the effect that occurs when a solution is exposed to light. When the true solution (pictured left) is illuminated with light, the solution will not scatter light, whereas in the colloidal system (right image), the light will be scattered. It happens because the colloidal particles have relatively large particles to be able to scatter the rays. In contrast, in the true solution, the particles are relatively small so that the scattering occurs only slightly and is very difficult to observe.
• Brownian motion
Brownian motion is the movement of colloidal particles that always move straight but not erratic (random or irregular motion). If we observe colloids under an ultra microscope, then we will see that the particles will move to form zigzags. This zigzag movement is called Brownian motion. The particles of a substance are constantly moving.
The movement may be random as in liquids and gases, or simply vibrate in places such as solids. For colloids with a liquid or gas dispersing medium, the movement of particles will result in collisions with the colloidal particles themselves. The collision took place from all directions. Because the particle size is small enough, the collisions that occur tend to be unbalanced. So there is a resultant collision that causes changes in the direction of motion of particles resulting in the motion of zigzag or Brownian motion. The smaller the size of colloidal particles, the faster Brownian motion occurs. Similarly, the larger the size of colloidal particles, the slower the Brownian motion occurs. This explains why Brownian motion is difficult to observe in solution and is not found in solids (suspension). Brownian motion is also affected by temperature. The higher the temperature of the colloidal system, the greater the kinetic energy of the dispersed medium particles. As a result, Brown's motion of the dispersed phase particles is accelerating. Similarly, the lower the temperature of the colloidal system, the more slow the Brownian motion.
• Absorption
Absorption is the absorption of particles or ions or other compounds on the surface of colloidal particles caused by the surface area of the particles.
Try to explain about the dispersion system and for example
BalasHapusWhen a substance is mixed with ain substances, then aka occur uniformly distributing from a substance to another substance called a dispersion system. For example: Starchy starch when put into hot water will form a dispersion system, with water as "dispersing medium" and starch flour is called "dispersant".
HapusAyu,
BalasHapusPlease explain briefly the tyndall effect and give an example ?
Tyndall effect is the effect of light scattering by colloidal particles. Examples of the effects of tyndall are the lights of the car at night when there is dust, sunlight through the leaves, the occurrence of blue during the day, and the red / orange in the sky at sunset.
HapusWHAT THE USE OF COLOID ?
BalasHapusUSE OF COLLOID
HapusColloidal system is widely used in everyday life, This is due to the important characteristic properties of colloids, which can be used to mix substances that can not be mutually homogeneous and stable dissolve for large-scale production.
The following is an explanation of colloid applications:
1. Bleaching Sugar
Cane-colored sugar cane is bleached. By dissolving the sugar into water, then the solution is passed through the diatomaceous colloidal or carbon dioxide system. The colloidal particles will adsorb the dyestuff. The colloid particles adsorb the dye from the sugar cane so that the sugar can be white.
2. Blood Clots
Blood contains a number of protein colloids that are negatively charged. In the event of injury, the lesion may be treated with a stiptic or alum pencil containing Al3 + and Fe3 + ions. The ions help to keep the colloid particles in the protein neutral so that the clotting process can be more easily done.
3. Purifying Water
Current tap water (PDAMs) contain colloidal particles of clay, mud, and other negatively charged particles. Therefore, to make it feasible to drink, steps should be taken to allow the colloid particles to be separated. This is done by adding alum (Al2SO4) 3.Ion Al3 + contained in alum it will dihidroslisis forming particles of Al (OH) 3 colloids are positively charged.
After that, Al (OH) 3 removes the negative charges from the clay / mud colloidal particles and coagulates in the mud. The mud is then settled with alum that also settles due to the influence of gravity.
Explain why colloid dispersion is stable or not easily coagulated?
BalasHapusThe colloidal dispersion is stable or not easily coagulated by the presence of brown motion of colloidal particles which makes the gravitational force has no effect
Hapus