Liquid water – made from two types of gas. Makes no sense to me, whatsoever. Water seems to be one of the strangest substances and we completely take it for granted that, apparently, it’s made of gas!
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Hydrogen and oxygen are not gases, they are solid, liquid or gas depending on temperature. Just like a lot of other stuff like water, and even metals like iron. The difference is the temperature needed for a specific state. You need a very low temperature to turn oxygen and hydrogen into a liquid, Iron, on the other hand, needs a high temperature to become a liquid. The temperature depends on how the molecules/atoms interact with each other
Some more complex molecules break apart if you heat them instead of becoming a liquid so liquid wood is not possible
Both hydrogen and Oxygen form a diatomic compound, two atoms, H2 and O2. The structurally us H-H and O=O where a – is a single valence bound and = is a double valence bound, that is shared electrons.
Water is not a mixture of H2 and O2 is the result of a chemical reaction that produces H2O. If you look at the structure of H2O it is not a line but more like a V with an internal angle of 104.5 degrees
H H
/
O
The result of that geometrical configuration and atoms’ attraction to share electrons is that they end up a bit more of the time at the O and a bit less of the time at the H. The result is that O gets a slightly negative charge and the H is slightly positive. It is called a polar molecule.
Both H2 and O2 are two identical atoms in a line so you do not get sides with different charges.
+ +
H H
/
O
–
The result is when water is solid or liquid it lines out so the O from one molecule is close to a H of another molecule. That forms a strong intermolecular bond because of the change difference, it requires lots of energy to break. There is two H in a molecule that can bind to O from two different molecules can be bound to the H of a single molecule, you can form large structures like that. A strong bound and molecules that all get bound together result in a high melting and vaporization temperature compared to H2 and O2
The melting point of O2 is −259.16 °C, −434.49 °F and the boiling point is −252.879 °C, −423.182 °F
The melting point of H2 is (−259.16 °C, −434.49 °F and the boiling point i −252.879 °C, −423.182 °F
That is a lot lower the water because of weaker bounds between molecules
If you combine hydrogen and carbon you can the Methane CH4. The geometry is
H
|
H-C-H
|
H
Because of the symmetry, there is no part with a negative and positive change and the bounds between atoms are weaker. The melting point is −182.456 °C −296.421 °F and the boiling point is 161.5 °C −258.7 °F That is closer to H2 and O2 than water because it is not polar and binding energies the lower. It is still higher the H2 and O2 because you have 4H on the side that all other elements.
I you have a change of 7 carbon atoms with hydrogen attached you have heptane, C7H16, with a melting temperature of −90.549 °C −130.988 °F; and a boiling temperature of 98.38 °C 209.08 °F. That is liquid at room temperature. Heptane is one of the multiple carbohydrates in gasoline.
If you get to 8 carbon atoms with Octane the boiling temperature is 125C, which is higher than water. If you go to 14 carbon in the chain the melting point is 4C and boiling 254C, so both are higher than water
So the more bounds you have between molecules with just C and H the higher melting and boiling temperature
So melting and boiling temperatures depend both on strength of the bounds between molecules and the number of bounds. Water has stronger bounds the hydrocarbons so they need more bounds to get as high or higher melting and building temperature.
Carbon by itself can bind to 4 other atoms and the result is you can get in theory unlimited molecule size. Graphite and diamonds are just lost carbon atoms in a large molecule. Graphite will break apart if heated to 3630 °C; 6560 °F, it can’t be a liquid at normal atmospheric pressure. The higher temperature is because all of it can be a single molecule and bounds in molecules are stronger between molecules. If you heat water to around 3000C the majority of it will be broken apart too, so a lot more energy is need then to separate water molecules from each other.
This is the explanation for the high melting temperature of some metals too, they can form large crystals with all atoms bound together like carbon but in a slightly different what which results in weaker bonds. The higher melting point of a metals is Tungsten at 3422 °C so slightly lower than when graphite breaks apart
So water is not made of two gases but is a compound of two elements. The melting temperature is a lot higher than just a molecule of the individual element because it gets a positive and negative changed part that results in stronger bounds between molecules so high melting and boiling temperature.
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