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Change of States of Matter – [B] Effect of change of Pressure

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Can Matter change its States?
States of Matter
What is Matter? What is its Characteristics?


[B] Effect of change of Pressure –

By increasing pressure, particles of matter can be brought close together. When we apply pressure on a gas enclosed in a cylinder, it  starts compressing and converts into liquid. Thus, by applying pressure and reducing temperature a gas can be liquefied.
Example – Carbon dioxide is a gas under normal conditions of temperature and pressure. It can be liquefied by putting pressure at ordinary temperature. Solid carbon dioxide (CO2) is stored under high pressure. Solid COgets converted directly to gaseous state on decrease of pressure to 1 atmosphere without coming into liquid state. This is the reason that solid carbon dioxide is also known as dry ice.

Thus, pressure and temperature determine the state of a substance i.e. solid, liquid or gas.


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Change of States of Matter – [A] Effect of change of Temperature


PHASE DIAGRAM – CO2

7 thoughts on “Change of States of Matter – [B] Effect of change of Pressure”

  1. Pingback: Change in States of Matter – [A] Effect of change of Temperature – Freakgenie

  2. The answer here is wrong. Carbon – dioxide can never be converted into liquid state no matter how much you compress it. It changes its form only from gas to solid.

    1. Phase diagram -Carbon dioxidehttps://freakgenie.comwp-content/uploads/2021/07/phase-diagram-CO2.jpg
      Hope this advanced insight will fulfill your curiosity.
      In contrast to the phase diagram of water, the phase diagram of CO2 has a more typical melting curve, sloping up and to the right. The triple point is −56.6°C and 5.11 atm, which means that liquid CO2 cannot exist at pressures lower than 5.11 atm. At 1 atm, therefore, solid CO2 sublimes directly to the vapor while maintaining a temperature of −78.5°C, the normal sublimation temperature. Solid CO2 is generally known as dry ice because it is a cold solid with no liquid phase observed when it is warmed.

    2. I think that the author is correct while stating that carbon dioxide can be converted to liquid phase. The concept becomes very easy to understand if one is familiar with phase diagrams. The one that the author has attached to the reply to your question illustrates this concept. The state of any substance depends on the temperature and pressure it is subjected to. If the pressure was over 5.11 atm, then even CO₂ can be converted to liquid. Depending on the temperature in such a scenario, you could very easily convert CO₂ to a liquid.

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