Chemistry question

[Lamber]

Hello, made a promise of looking after my little brother in law during homework. Now I'm stuffed as I can't come up with the answers / examples.

 

remember changes of matter phases. Solid, liquid and gas. So an example is Ice, water and water vapour; we are looking for another example where the liquid phase are know as a useful product. We tried everything from gold, iron etc. Boiling point, melting point in periodic table does not help if we can't label the liquid phase:(

That is what we are struggling with tonight. Because it must bé an example used in all three phases.

 

 

Any ideas?! Thanks

 

To get technical, steam is not a phase seeing as it contains water. Enthalpy must be added to steam until it becomes "dry steam" which is known as "superheated vapour", only then can it be classified as a gas.

 

To answer you question- ammonia (NH3) is used in fridge plants (and your common household fridge) as coolant. It's in the form of a liquid, then after the compression cycle it becomes a gas and then again a liquid once cooled down. NH3 is also used as a fertiliser in its solid state. I know it's not an element, don't know if it's in your scope.

[Dr Snuggles]

errm, NaCl or sodium chloride, or more commonly known as salt. When a solid we use it as a food substance or for melting ice. Molten salt is used in solar concentrators to transport the capture solar heat and trasnferred to a secondary medium like water which is turned into steam.

[jmaccelari]

Buthane - gas LPG, liquid for transport and for rockets its a solid... I think

Nope it's a (different) liquid or else a really nasty solid chemical. Not the same stuff.

[MeridaHFS]

The hub, where all you questions are answered! Got to love this place

[ibruegge]

The hub, where all you questions are answered! Got to love this place

Exactly, little brother in law is hugely impressed (he is 13) - and says wow, "so many smart friends you have" :-)

[Helpmytrap]

Exactly, little brother in law is hugely impressed (he is 13) - and says wow, "so many smart friends you have" :-)

Little does he know that you don't actually have any friends.

[Minion]

Molten salt is used in solar concentrators to transport the capture solar heat and trasnferred to a secondary medium like water which is turned into steam.

I don't think they use NaCl in those, rather nitrogen-based salts like KNO3.

[ibruegge]

Little does he know that you don't actually have any friends.

or any knowledge.

[Dr Snuggles]

I don't think they use NaCl in those, rather nitrogen-based salts like KNO3.

 

indeed they do, and it's normally a mix of nitrates, eg KNO3, CaNO3, or NaNo3. The use of table salt was a deliberate, but somewhat misleading oversimplification. Agreed.