Dissolution (1 Viewer)

[=)(=]

Is the dissolution of even a soluble salt an equilibrium, for example

Is this just occuring in the case it is a saturated solution?

 

[carrotsss]

there’s always gonna be a tiny tiny tiny bit of NaOH from the reverse reaction + yeah the reaction also applies for when it’s saturated

 

[=)(=]

ohh okay ic thx

 

[wizzkids]

This is a stupid question in my opinion. For sodium hydroxide, the answer is "No", it is not an equilibrium reaction. Sodium hydroxide is deliquescent, the solid spontaneously hydrates when ever water is around. There is a large ΔH and large ΔG for this reaction, and you can feel the solid getting warm, so "No" this is not an example of an equilibrium reaction, it goes spontaneously to the right. That suggested answer is stupid.

 

[=)(=]

ohh okay fair but if say you add a lot of naoh until the solution is fully saturated why would there not be an equilbirium?

 

[wizzkids]

I dare you to actually try to saturate a solution of sodium hydroxide, see if you can do it.
But be VERY careful, there will be a lot of heat generated. It will look like a slushie with steam coming off, and as soon as it cools down, it will turn back to solid.

 

[=)(=]

I dare you to actually try to saturate a solution of sodium hydroxide, see if you can do it.
But be VERY careful, there will be a lot of heat generated. It will look like a slushie with steam coming off, and as soon as it cools down, it will turn back to solid.

lol in that case ill raid the school stock hahaha

 

[ATAR + Life = 99.95]

Is the dissolution of even a soluble salt an equilibrium, for example
View attachment 39528
Is this just occuring in the case it is a saturated solution?

Is this a part of the mathematics course for the HSC? I don't recognise it.

 

[=)(=]

Is this a part of the mathematics course for the HSC? I don't recognise it.

No its hsc chem

 

[Luukas.2]

ohh okay fair but if say you add a lot of naoh until the solution is fully saturated why would there not be an equilbirium?

A saturated solution of anything involves a solubility equilibrium. An unsaturated solution is not an equilibrium system.

It may be difficult to achieve a saturated solution in a specific case. Sodium hydroxide has a very high solubility of around 1 kg/L at 25 ^oC (according to Wikipedia, and referenced the CRC Handbook), and more will dissolve initially because the dissolution is exothermic, but the system will still exist as a solubility equilibrium once saturated. FYI, other compounds with very high solubility include sucrose, urea, silver nitrate (above 2.5 kg/L at room temperature), and ammonium nitrate can dissolve more than 10 kg per L in boiling water.