Solid, Liquid or Gas: Identifying Matter

In summary, physical state may change upon temperature, pressure and even time.Network compounds are usually solid, as they possesses very strong covalent bonding, so are ionic compounds, because ionic bonds are strong as well.H2 is a gas, because it has almost no intermolecular force between the H2 molecules.
  • #1
Roxy
52
0
How do you know if something is a solid, liquid or gas. Like ferrous iodide or sodium phosphate?
 
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  • #2
As far as I know, there is no way to tell just by looking at the chemical formula.

- Warren
 
  • #3
Physical state may change upon temperature, pressure and even time...
 
  • #4
chem_tr said:
Physical state may change upon temperature, pressure and even time...

Could you please give an example of a phase trasition of the first kind in which,assuming a system in one phase (e.g.solid) and nonmodifying the external conditions (temperature,pressure and other parameters),the system would undergo a phase transition (into e.g.fluid)??

Daniel.
 
  • #5
Well,...you can sort of guess as to which "state" a compound is by looking at what bonds it together;

For example, MgBr2 is probably a solid because of the ionic bonds;
Li2 is a solid by metallic bonds
O2 is a gas, because its covalent bond is very weak
CH3COH may be liquid, because of the dipole-dipole intermolecular attraction with that OH end there

Network compounds are usually solid, as they possesses very strong covalent bonding, so are ionic compounds, because ionic bonds are strong as well

H2 is a gas, because it has almost no intermolecular force between the H2 molecules

Well, given the formula, you can generally "sorta" guess as to what its state would be at STP--to verify this and to check for other temperatures/pressure, see a phase diagram for your compound
 
  • #6
dextercioby said:
Could you please give an example of a phase trasition of the first kind in which,assuming a system in one phase (e.g.solid) and nonmodifying the external conditions (temperature,pressure and other parameters),the system would undergo a phase transition (into e.g.fluid)??

Daniel.
I think chem_tr may be referring to non-equilibrium (metastable) states.
 
  • #7
It's the only reasonable explanation...

Daniel.
 
  • #8
Yes, I meant metastable states; Gokul is right.
 
  • #9
dextercioby said:
Could you please give an example of a phase trasition of the first kind in which,assuming a system in one phase (e.g.solid) and nonmodifying the external conditions (temperature,pressure and other parameters),the system would undergo a phase transition (into e.g.fluid)??

Daniel.

Milk. Milk turns into powder over time.

Although, I'm not sure, as technically milk is composed of a lot of elements, you may be looking for a compound or singular element, not just a mixture.
 
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  • #10
Gokul43201 said:
I think chem_tr may be referring to non-equilibrium (metastable) states.

'Metastable' can be a bit misleading though. Diamonds are pretty stable at STP.
 
  • #11
HungryFox said:
Milk. Milk turns into powder over time.

That's evaporation, not a phrase transition.
 
  • #12
That's necromancy, last post in the thread was almost 5 years old.
 

1. What is matter?

Matter is anything that takes up space and has mass. It can exist in three states: solid, liquid, or gas.

2. What is the difference between a solid, liquid, and gas?

A solid has a fixed shape and volume, a liquid has a fixed volume but takes the shape of its container, and a gas has neither a fixed shape nor volume.

3. How can I identify whether a substance is a solid, liquid, or gas?

The physical properties of a substance, such as its shape, volume, and ability to flow, can help identify its state. For example, solids are usually hard and maintain their shape, while liquids can flow and take the shape of their container, and gases are able to expand and fill their container.

4. Can a substance change from one state to another?

Yes, substances can change states through physical processes such as melting, freezing, evaporation, and condensation. These changes in state are reversible, meaning the substance can go back to its original state under the right conditions.

5. What factors can affect the state of matter?

The state of matter can be affected by temperature and pressure. Generally, increasing the temperature will cause a substance to change from a solid to a liquid to a gas. Decreasing the temperature will have the opposite effect. Changes in pressure can also cause substances to change states, such as when water boils at a lower temperature at higher altitudes due to decreased air pressure.

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