States of Matter

There are five main states of matter. Solids, Liquids, Gases, Plasmas, and Bose – Einstein condensate. Each of these states is also known as the phase and the matters that are present in these are considered as part of these phases. Elements can move from one phase to another if special physical forces are applied and a change in phase takes place. Example: heating of ice will change it from solid phase to liquid or further heating would change it to gaseous phase.

The classification of matter into solids, liquids and gases is termed as physical classification of matter.
In a solid, the constituent particles like atoms, ions or molecules are most closely packed and have the strongest inter molecular force of attraction.
As a result of this, particles are fixed in their position and do not have any freedom of motion except that of vibration about their mean position.
These gives rise to the following characteristic properties to a solid.

• A definite shape and volume
• In-compressibility
  
• No fluidity
• Poor diffusibility
• Rigidity
  

Characteristics of solids

1. Solids maintain their volume independent of the size of shape of container in which they are placed in.
2. Solids are rigid and have definite shape.
3. Solids diffuse very slowly compared to liquids and gases, due to close packing
4. Solids are incompressible
5. Most solids melt on heating, and some sublimate.
6. Solids have very high mass to volume ratio or density compared to liquid or gases.
   

1. The liquid state lies in between the gaseous and solid state as there is neither the ordered arrangement like in solids nor the complete disorder of constituents as in gas.
2. It is generally observed that the properties closely resemble those of gases while a few characters match those of solids.
3. In light of kinetic molecular theory, liquids may be regarded as a continuation of gases into the region of small volumes and high inter-molecular attraction.
4. The cohesive forces in liquid have been stronger than those in gases and that keeps these molecules confined to a definite volume.
5. The positions of the molecules in liquids are not rigidly fixed.
6. At the same time these forces are not strong enough to entirely eliminate the movements of the molecules in the liquid.
   

Properties of liquids

• Appreciable forces of attractions exist between the molecules of a liquid.
• The molecules in a liquid are in a state of random motion although the extent is appreciable much smaller in comparison to gases.
• The average Kinetic energy of the molecules in a liquid is proportional to the absolute temperature.
  

Increase in temperature would increase the proportion of the energized particles and results in lowering of attractive forces between them and ultimately increase the vapour pressure of the liquid.The rate of evaporation of a liquid depends upon the following factors:

• The temperature of the liquid
• Attractive forces in the liquid
• Surface are of the liquid
• Pressure above the liquid
  

In 1654, Otto Von Guericke performed Magdebur hemisphere experiment to show that the air exerted pressure and put the foundations for modern concept of gaseous state.

Physical characteristics of gases

All gases show some common characteristics. These are as follows:

• Gases maintain neither volume nor shape and completely fill the container in which they are introduced.
• Gases expand when heated
• Gases diffuse rapidly; we can smell perfume even when applied at a distance very fast
• Gases are highly compressible; if pressure increased then volume decreases
• Almost all gases except a few are colorless
  

Examples of colored gases

Nitrogen di-oxide - reddish- brown gas
Iodine - violet gas
Chlorine - greenish- yellow gas

Measurable properties of gases

The behavior of gases can be described in terms of certain parameters.

Mass and amount
The mass of gas can be determined by weighing the container containing the gas and then emptying the container by taking out the gas and weighing the empty container again.
The difference between the two weights would give the mass of gas.

Volume
Volume of a gas is equal to the volume of its equation.
Volumes can be expressed in terms of liter (L), milliliter (mL), or cubic centimeter (cm³)
The SI unit of volume is cubic meter (m³).

Properties of gases

Gaseous properties are of two classes and they are intensive and extensive.
The properties that depend upon the amount of gas like mass and volume are called extensive while in uniform gases, where the properties are independent of amount like pressure and temperature are called intensive property.

Changes of state or phase for a substance can be described on a graph. The graph shows that when water in the solid state absorbs energy its temperature increases until it reaches 0^oC (32^oF) its melting point. At this temperature the sample continues to absorb energy, but its temperature does not change. This is because the additional energy is breaking the water molecules out of the fixed solid state. The solid ice changes into liquid water.



Once the change of state is complete the temperature begins to rise again. The temperature of the liquid rises as heat energy is absorbed until it reaches the boiling point -100^oC. Again the temperature stays the same as the additional energy breaks the molecule free of the liquid state. The liquid water changes into water vapor. Once the change from the liquid state to the gas state is complete the temperature begins to rise again.

There are four possible physical states of matter.

1. Gas: Matter in gaseous state relies on its container for both shape and volume.
2. Liquid: Matter in the liquid state takes on the shape of whatever container it is put in. However, a liquid has a definite volume that does not depend on the container it is put in.
3. Solid: Matter in the solid state has a definite shape and volume regardless of the container.
4. Plasma: A unique state of matter that only appears to be solid. In reality it is an ionized gas. (To ionize an atom or collection of atom is to give it an electrical charge either by adding or removing one or more electrons)

Matter can change both physically and chemically. A physical change is a change in a substance's shape, size or state. No chemical reactions is involved with a physical change. The particles that make up the substance remain essentially the same. So a diamond that is pulverized into diamond powder or a potato that gets mashed are both example of a physical change. In each instance the diamond and potato take on a different appearance but they are still made of same particles.

The substance we have just described illustrate the three states of matter: solid, liquid and gas. These are defined and illustrated as follows

The state of a given sample of matter depends on the strength of the forces among the particles contained in the matter; the stronger these forces the more rigid the matter.

Here in this page we are going to discuss about Bose Einstein Condensate or fifth state of Matter concept.

1. The emergence of BEC or Bose Einstein condensate as the fifth state of matter was on vogue for long but was approved only recently and is considered as a low energy form of matter.
   
2. This matter is considered as matter beyond solids but is less energetic than solids.
   
3. Bose Einstein condensate occurs in the fractional micro-Kelvin range, or less than millionths of a degree above absolute zero.
   
4. The atoms in a Bose Einstein condensate are locked into all of the same attributions as each other and they are literally indistinguishable.
   
5. These particles can slow light down to the residential speed limit. These particles can flow without friction.
   
6. These particles can demonstrate the strangest characteristics of quantum mechanics. They are effectively super-atoms, groups of atoms that behave as one.
   
7. The classic example of BEC was considered as Helium for a long time. The transition of liquid Helium into super-fluid Helium, the viscosity disappears and it behaves like a quantum fluid.
   
8. The possibility of a phase change into a Bose-Einstein-like condensate theoretically applies for all bosonic particles and may actually include the electron-hole pairs called exciton s and half exciton, and half photon quasi-particles called polaritons.
9. Applications of Polaritons have led to development of new generation cameras like the charged coupled device or CCD chips in digital cameras.
   
10. The magical properties of super-fluidity where matter flows with zero friction can help us prevent the loss of electric power during transmission, faster computers and faster communication modules.
    

Catalysts are agents which accelerates a chemical reaction without having entered the reaction or being used by it. These catalysts may either be inhibited or destroyed in secondary processes.

Examples:

Hydrogenation reaction

H₂

H₂C=CH₂ -----------------------> H₃C-CH₃

catalyst Low temperature catalysts using a copper-zinc technology would be better used in conversion of carbon monoxide into hydrogen and carbon dioxide. CO + H₂O → CO₂ + H₂

Low temperature CO catalysts are used in manufacturing personal protection equipment which are lightweight and compact thus enabling the effective use of the equipment against CO poisoning. These low temperatures catalysts work at ambient temperatures and relatively high ambient moisture present in fires, enabling them to be used without any outer protection adsorbent material layer.

Use of low temperature CO conversion catalyst has many advantages in the production of hydrogen gas and ammonia synthesis. An iron oxide-chrome oxide catalyst used to carry out the above reaction allows the reaction at very feasible temperatures of 650^oF with three to ten years of life. Use of C18 type low temperature conversion catalysts result in 99% conversion of carbon as compared to 90-95% when iron oxide-chrome oxide catalysts are used at their lowest effective temperature. Activity of low temperature catalysts are appreciably affected when the catalyst is subjected to higher temperatures than the normal level of operation.

Use of low temperature catalysts are not shown to be practical at low pressures. These catalysts are known to exhibit highly active sites and high catalytic activity. Catalysts of noble metals are active for the hydrogenation of aromatics, reactions which are exothermic, at very feasible temperatures.

Low temperature catalysts are sensitive to both catalyst poisons and abnormal operating conditions whose activity is affected even by trace quantities of sulfur. Low temperature catalysts like iron oxide- chrome oxide catalysts and C₁₈ low temperature conversion catalysts are a few used widely.