Ethyl vanillin: Gets ice cold when mixed with alcohol!

[egosum333]

So after a couple years, I just had the coolest experience. I have never diluted such a large batch of ethyl vanillin before today. I noticed that when I mixed 70 grams of EV with 280 grams of perfumers alcohol, the glass jar got extremely cold…like it had been taken out of the refrigerator!

In case you are wondering, I just diluted about 18 different aroma molecules and essential oil in alcohol using the same bottles and alcohol from the same location. None of the others are cold.

What reaction would cause the solution to get so cold?

 

[ourmess]

Any reaction can be endothermic (heat-absorbing) or exothermic (heat-generating). Sounds like dissolving vanillin is endothermic - doesn't really mean anything beyond knowing that. ;p

 

[egosum333]

Any reaction can be endothermic (heat-absorbing) or exothermic (heat-generating). Sounds like dissolving vanillin is endothermic - doesn't really mean anything beyond knowing that. ;p

That is so cool though, thank you for explaining! I didn’t pay much attention in chemistry class, so the lack of scientific knowledge makes this seem like magic ☺️

 

[pkiler]

Yes, thermic reactions are fun!

 

[Shrike]

Any reaction can be endothermic (heat-absorbing) or exothermic (heat-generating). Sounds like dissolving vanillin is endothermic - doesn't really mean anything beyond knowing that. ;p

The whole point was the it was cool. And if OP is accurate, it is really cool.

 

[Hedione HC]

We also know this "phenomenon" from the household. In order to generate great cold in a short time with little effort, for example to make homemade ice cream, table salt is mixed with ice cubes. This cold mixture is very effective in extracting energy = heat from the environment and can therefore be used as a simple ice cream machine. The simple explanation for this is that during the transition from a solid aggregar state to a liquid state, energy is needed that is extracted from the environment.

(I am happy to leave the exact explanation, if it is necessary at all in this context, to others.)

 

[David Ruskin]

Heliotropin dissolved in DPG does the same thing.

 

[xii]

There isn't really a reaction here. Not in chemical sense anyway. Formation of a solution virtually always evolves or absorbs heat depending on which state has higher energy.

 

[egosum333]

The whole point was the it was cool. And if OP is accurate, it is really cool.

Like…literally COOL LOL

 

[egosum333]

This

We also know this "phenomenon" from the household. In order to generate great cold in a short time with little effort, for example to make homemade ice cream, table salt is mixed with ice cubes. This cold mixture is very effective in extracting energy = heat from the environment and can therefore be used as a simple ice cream machine. The simple explanation for this is that during the transition from a solid aggregar state to a liquid state, energy is needed that is extracted from the environment.

(I am happy to leave the exact explanation, if it is necessary at all in this context, to others.)

This a beautiful explanation and as someone who used to make homemade vanilla ice cream in the Deep South (USA) with my grandmother, it is something I have personally experienced. How ironic that “vanilla” is apart of both stories.

Thank you for providing this example!

 

[egosum333]

Heliotropin dissolved in DPG does the same thing.

I have heliotropin, DPG and time on my hands today! I’m going to try it out.

 

[egosum333]

There isn't really a reaction here. Not in chemical sense anyway. Formation of a solution virtually always evolves or absorbs heat depending on which state has higher energy.

Why is it that none of the other solutions displayed any (obvious) change in temperature?

David mentioned Heliotropin would do the same, but that wasn’t one the 18 solutions. I’m gonna try it though lol.

 

[xii]

Why is it that none of the other solutions displayed any (obvious) change in temperature?

I don't know what makes ethyl vanillin special. It's much easier to explain why strong acids or bases mix with water exothermically and weak ones not so. Then again, there is an actual reaction occuring in that case.

 

[tensor9]

Every dissolution has an associated heat release or absorption (enthalpy of dissolution). Dissolution means dissolving something, a solute, in something else, a solvent. A chemical reaction need not take place to observe this.

Though dissolution is typically considered a physical process, in actuality there is on a spectrum from leaning more towards a chemical change to purely physical. Dissolution of a salt in water, for example, could be argued as a chemical change, since the starting material is bound by ionic forces and the resulting solution inevitably contains coordinate covalent bonds (water bound to the metal ions in solution), which did not exist in the salt beforehand. On the other end is dissolution of a molecule (sugar, vanillin, etc.) where there is no real chemistry taking place. There is always heat exchange involved in this process. Regardless, intermolecular forces (the physical attraction between ions, e.g., Na+ and Cl- from table salt, or between molecules, e.g., sugar in water) play a part in every dissolution process. Materials' boiling points are what they are because of intermolecular forces, after all something has to hold them, water or ethanol molecules for example, "together" or else everything would be a gas!

Regardless of where the system at hand falls on this spectrum, the following general process are involved:

heat transfer:
overcoming solute-solute intermolecular forces (absorbs heat)
overcoming solvent-solvent intermolecular forces (the molecules must part ways to make room for the solute!, absorbs heat)
solute-solvent intermolecular forces (may absorb or release heat)

Depending now how the above process shakes out, dissolving a solute in a solvent can result in a net absorption of heat (it gets cold) or a net release of heat (it gets hot).

In the case of vanillin in ethanol, there is a net absorption of heat from the surroundings, so it gets cold.
As a counterexample and to keep with molecule-molecule systems, when you mix water and DMSO (dimethyl sulfoxide), the solution gets VERY hot.

Advanced reading:
Since processes generally tend towards more stable, less energetic states by releasing heat, why would an endothermic process (absorbs heat) be spontaneous? Entropy.

This is what happens with the entropy of the dissolution process:
entropy (disorder):
change in solute entropy is always positive
change in solvent entropy can be positive or negative (in the case of dissolving salts, the attraction of solvent molecules to the dissolved ions actually decreases total solvent entropy because of ordering around said ions)

If you can quantify the heat change (enthalpy) and change in disorder (entropy), you can calculate whether any process is spontaneous by the Gibbs equation:

delta G = delta H - T*(delta S)
(delta means "change in", or final minus initial)
H = enthalpy
T = temperature
S = entropy
G = Gibbs free energy

If delta G is negative, the process is spontaneous, if it's positive it will not happen at that temperature.

If delta H is negative, heat is released (exothermic), which helps delta G be negative.
If delta S is positive (more entropy, ordisorder), the negative sign in the equation helps delta G be negative.

In general, spontaneous process tend to release heat and increase entropy.
BUT, if the entropy change is large enough, you can overcome an absorption of heat. (The T*(delta S) term is larger than the delta H term.)

Turns out, with all the considerations above, when you plug in the enthalpy and entropy numbers, delta G ends up negative and vanillin dissolves in ethanol all by itself, because of entropy, and the solution ends up cold.

 

[mnitabach]

Every dissolution has an associated heat release or absorption (enthalpy of dissolution). Dissolution means dissolving something, a solute, in something else, a solvent. A chemical reaction need not take place to observe this.

Though dissolution is typically considered a physical process, in actuality there is on a spectrum from leaning more towards a chemical change to purely physical. Dissolution of a salt in water, for example, could be argued as a chemical change, since the starting material is bound by ionic forces and the resulting solution inevitably contains coordinate covalent bonds (water bound to the metal ions in solution), which did not exist in the salt beforehand. On the other end is dissolution of a molecule (sugar, vanillin, etc.) where there is no real chemistry taking place. There is always heat exchange involved in this process. Regardless, intermolecular forces (the physical attraction between ions, e.g., Na+ and Cl- from table salt, or between molecules, e.g., sugar in water) play a part in every dissolution process. Materials' boiling points are what they are because of intermolecular forces, after all something has to hold them, water or ethanol molecules for example, "together" or else everything would be a gas!

Regardless of where the system at hand falls on this spectrum, the following general process are involved:

heat transfer:
overcoming solute-solute intermolecular forces (absorbs heat)
overcoming solvent-solvent intermolecular forces (the molecules must part ways to make room for the solute!, absorbs heat)
solute-solvent intermolecular forces (may absorb or release heat)

Depending now how the above process shakes out, dissolving a solute in a solvent can result in a net absorption of heat (it gets cold) or a net release of heat (it gets hot).

In the case of vanillin in ethanol, there is a net absorption of heat from the surroundings, so it gets cold.
As a counterexample and to keep with molecule-molecule systems, when you mix water and DMSO (dimethyl sulfoxide), the solution gets VERY hot.

Advanced reading:
Since processes generally tend towards more stable, less energetic states by releasing heat, why would an endothermic process (absorbs heat) be spontaneous? Entropy.

This is what happens with the entropy of the dissolution process:
entropy (disorder):
change in solute entropy is always positive
change in solvent entropy can be positive or negative (in the case of dissolving salts, the attraction of solvent molecules to the dissolved ions actually decreases total solvent entropy because of ordering around said ions)

If you can quantify the heat change (enthalpy) and change in disorder (entropy), you can calculate whether any process is spontaneous by the Gibbs equation:

delta G = delta H - T*(delta S)
(delta means "change in", or final minus initial)
H = enthalpy
T = temperature
S = entropy
G = Gibbs free energy

If delta G is negative, the process is spontaneous, if it's positive it will not happen at that temperature.

If delta H is negative, heat is released (exothermic), which helps delta G be negative.
If delta S is positive (more entropy, ordisorder), the negative sign in the equation helps delta G be negative.

In general, spontaneous process tend to release heat and increase entropy.
BUT, if the entropy change is large enough, you can overcome an absorption of heat. (The T*(delta S) term is larger than the delta H term.)

Turns out, with all the considerations above, when you plug in the enthalpy and entropy numbers, delta G ends up negative and vanillin dissolves in ethanol all by itself, because of entropy, and the solution ends up cold.

Hahahah! There are, of course, not any covalent bonds forming between sodium or chloride ions and water when table salt dissolves in water. This is basic middle-school chemistry, so not sure where you are coming up with this absurdity...

 

[tensor9]

Hahahah! There are, of course, not any covalent bonds forming between sodium or chloride ions and water when table salt dissolves in water. This is basic middle-school chemistry, so not sure where you are coming up with this absurdity...

Ahh someone who has no background in inorganic chemistry chiming in. Look up COORDINATE covalent bond. It’s a general term, and in the case the lone pair comes for the water. Now, since the cation is sodium, the degree of covalency is exceedingly low. But you do realize that every metal ligand bond is on a spectrum, right? If it makes you happy, let’s just say the sodium ions form a coordination complex with water to do away with this apparently contentious term.

 

[mnitabach]

Ahh someone who has no background in inorganic chemistry chiming in. Look up COORDINATE covalent bond. It’s a general term, and in the case the lone pair comes for the water. Now, since the cation is sodium, the degree of covalency is exceedingly low. But you do realize that every metal ligand bond is on a spectrum, right? If it makes you happy, let’s just say the sodium ions form a coordination complex with water to do away with this apparently contentious term.

Thank you for clarifying!

 

[tensor9]

Thank you for clarifying!

No problem. Maybe you should refrain from rude remarks about things you apparently know nothing about.

Maybe my Ph.D. in inorganic chemistry has afforded me more in depth knowledge than basic middle-school chemistry would allow…

 

[mnitabach]

No problem. Maybe you should refrain from rude remarks about things you apparently know nothing about.

Maybe my Ph.D. in inorganic chemistry has afforded me more in depth knowledge than basic middle-school chemistry would allow…

Hahahahah!

 

[egosum333]

Every dissolution has an associated heat release or absorption (enthalpy of dissolution). Dissolution means dissolving something, a solute, in something else, a solvent. A chemical reaction need not take place to observe this.

Though dissolution is typically considered a physical process, in actuality there is on a spectrum from leaning more towards a chemical change to purely physical. Dissolution of a salt in water, for example, could be argued as a chemical change, since the starting material is bound by ionic forces and the resulting solution inevitably contains coordinate covalent bonds (water bound to the metal ions in solution), which did not exist in the salt beforehand. On the other end is dissolution of a molecule (sugar, vanillin, etc.) where there is no real chemistry taking place. There is always heat exchange involved in this process. Regardless, intermolecular forces (the physical attraction between ions, e.g., Na+ and Cl- from table salt, or between molecules, e.g., sugar in water) play a part in every dissolution process. Materials' boiling points are what they are because of intermolecular forces, after all something has to hold them, water or ethanol molecules for example, "together" or else everything would be a gas!

Regardless of where the system at hand falls on this spectrum, the following general process are involved:

heat transfer:
overcoming solute-solute intermolecular forces (absorbs heat)
overcoming solvent-solvent intermolecular forces (the molecules must part ways to make room for the solute!, absorbs heat)
solute-solvent intermolecular forces (may absorb or release heat)

Depending now how the above process shakes out, dissolving a solute in a solvent can result in a net absorption of heat (it gets cold) or a net release of heat (it gets hot).

In the case of vanillin in ethanol, there is a net absorption of heat from the surroundings, so it gets cold.
As a counterexample and to keep with molecule-molecule systems, when you mix water and DMSO (dimethyl sulfoxide), the solution gets VERY hot.

Advanced reading:
Since processes generally tend towards more stable, less energetic states by releasing heat, why would an endothermic process (absorbs heat) be spontaneous? Entropy.

This is what happens with the entropy of the dissolution process:
entropy (disorder):
change in solute entropy is always positive
change in solvent entropy can be positive or negative (in the case of dissolving salts, the attraction of solvent molecules to the dissolved ions actually decreases total solvent entropy because of ordering around said ions)

If you can quantify the heat change (enthalpy) and change in disorder (entropy), you can calculate whether any process is spontaneous by the Gibbs equation:

delta G = delta H - T*(delta S)
(delta means "change in", or final minus initial)
H = enthalpy
T = temperature
S = entropy
G = Gibbs free energy

If delta G is negative, the process is spontaneous, if it's positive it will not happen at that temperature.

If delta H is negative, heat is released (exothermic), which helps delta G be negative.
If delta S is positive (more entropy, ordisorder), the negative sign in the equation helps delta G be negative.

In general, spontaneous process tend to release heat and increase entropy.
BUT, if the entropy change is large enough, you can overcome an absorption of heat. (The T*(delta S) term is larger than the delta H term.)

Turns out, with all the considerations above, when you plug in the enthalpy and entropy numbers, delta G ends up negative and vanillin dissolves in ethanol all by itself, because of entropy, and the solution ends up cold.

Tensor9, thank you for the INCREDIBLE explanation. Seriously, you dropped some major knowledge and I was able able to follow all the way up to the advanced portion at the end 😅