Chemical change question

[Aivsta]

can somone tell me if i mixing two substances is a chemical change. If so please state why, and if not please state why as well.

P.S please answer asap.

[ecoli]

depends what substances are mixed... and whether or not said substances will react chemically.

[Aivsta]

substances like water and salt, or kool-aid and water, or makeing coffee.

[Jarryd]

I think salt and water is argueably a chemical reaction, because sodium chloride ionises. But i think with something such and 'kool aid' isn't it just a mixture of the compounds like the water doesn't actually react with it? As you can tell i have no idea what im saying and probably shouldn't be answering this question.

[RyanJ]

I think salt and water is argueably a chemical reaction, because sodium chloride ionises. But i think with something such and 'kool aid' isn't it just a mixture of the compounds like the water doesn't actually react with it? As you can tell i have no idea what im saying and probably shouldn't be answering this question.

 

Yea I agree, there is no reaction between the ions and the water... you just ger sodium ions and chloride ions

 

Cheers,

 

Ryan Jones

[dttom]

I don't think so, we may see NaCl(s) as an unity and when it 'reacts' with water, there're Na+ and Cl-, which are not the same as NaCl(s), so I think ionization is also a chemical reaction.

[RyanJ]

I don't think so, we may see NaCl(s) as an unity and when it 'reacts' with water, there're Na+ and Cl-, which are not the same as NaCl(s), so I think ionization is also a chemical reaction.

 

Technically it is (Any reaction is the transfer of electrons) but in the context of this question I don't think it is classed as such

 

So it is a chemical change but as soon as you evaporate the water it returns to its original state

 

Cheers,

 

Ryan Jones

[woelen]

Technically it is (Any reaction is the transfer of electrons) but in the context of this question I don't think it is classed as such

 

So it is a chemical change but as soon as you evaporate the water it returns to its original state

 

Cheers' date='

 

Ryan Jones[/quote']

What we learn from this example with NaCl is that the border between physical change and chemical change is not as sharp as we expected. Some phenomena cannot be classified in a clear true/false way.

 

The same holds for many things in chemistry, when is something called a bond and when is something called molecular interaction? When is something called a salt and when is something called a covalent compound? All these things have fuzzy borderlines.

[jdurg]

Technically it is (Any reaction is the transfer of electrons) but in the context of this question I don't think it is classed as such

 

So it is a chemical change but as soon as you evaporate the water it returns to its original state

 

Cheers' date='

 

Ryan Jones[/quote']

 

Very true, but you can also argue that when in a non-aqueous form, you have the crystal lattice with the Na+ ions and Cl- ions in there. When dissolving in water, you're simply breaking apart that lattice and no electrons change place. As a result, since there is no transfer of electrons there is no chemical reaction.

[RyanJ]

Very true, but you can also argue that when in a non-aqueous form, you have the crystal lattice with the Na+ ions and Cl- ions in there. When dissolving in water, you're simply breaking apart that lattice and no electrons change place. As a result, since there is no transfer of electrons there is no chemical reaction.

 

Thats true

 

I agree with woelen, it loos like this is one of those could-be-either topics

 

Cheers,

 

Ryan Jones