Why does boiled bottled water cool quicker?

[230K]

Hi

I have noticed this before, tea/coffee made from bottled water seems to cool much quicker than tea/coffee made from tap water. Anyone else noticed this?? Anyone have an explanation as to why??

Oh the joys of holidays.

230k

 

[glojo]

Hi

I have noticed this before, tea/coffee made from bottled water seems to cool much quicker than tea/coffee made from tap water. Anyone else noticed this?? Anyone have an explanation as to why??

Oh the joys of holidays.

230k

Tap water is cooler to start off with???

Sorry about that

regards
John

 

[KillerHERTZ]

holidays.

Time flows twice as fast on Holiday remember

 

[Spinal]

Total guess... but tap water may have a high salt content (or other dissolved heavy metals and minerals). This is turn raises the boiling point of the water, so when you boil it it doesn't really boil at 100C but more than that...

Total guess though...

 

[KillerHERTZ]

Check the side of the Bottle, it should give the total dry residue temp, it differs from make of water to water.

 

[NW_Merc]

If you add salt or other 'impurities' to water it will boil at a lower temperature not a higher temperature than what its supposed to, so it will start to boil at 85-95 deg C as opposed to 100 deg C (sorry I wasn't sniping - I'm a science teacher )

 

[Satch]

What is your altitude?

100C is the sea level boiling point but at 1000m water boils at about 96.7C and at 2000 metres 93.4C which means lower energy content.

 

[glojo]

If you add salt or other 'impurities' to water it will boil at a lower temperature not a higher temperature than what its supposed to, so it will start to boil at 85-95 deg C as opposed to 100 deg C (sorry I wasn't sniping - I'm a science teacher )

I onced watched a documentary that highlighted how some botted waters contained more impurities than tap water, what effects if any would this have?

Note to self
NW_Merc is a Science Teacher listen when he speaks science (mega respect)

 

[NW_Merc]

I got it! Bottled water is purer than tap water is it not (supposedly)? Hence bottled water would reach 100 deg C much earlier than tap water, thats assuming that tap water does not have impurities from the pipes etc

So if the bottled water hits 100 deg C it will also have the tendency to lose energy by particles leaving the surface in the form of steam much quicker, due to it being purer. Tap water will have less of a tendency to become cold because it does not lose as much energy to its surroundings as easily because of it being slightly less pure.

This is only theory if the bottled water was not one of those 'dodgy' varieties.... Apparently the cheaper ones are tap water that is bottled and sold as 'special bottled water'.

I onced watched a documentary that highlighted how some botted waters contained more impurities than tap water, what effects if any would this have?

It would boil but at a lower temperature, however it may well hold onto the heat better, i.e. for longer because it would have less energy to lose in the first place.

 

[Spinal]

If you add salt or other 'impurities' to water it will boil at a lower temperature not a higher temperature than what its supposed to, so it will start to boil at 85-95 deg C as opposed to 100 deg C (sorry I wasn't sniping - I'm a science teacher )

Sorry - I was just guessing I was thinking of freezing points... freezes lower, so boils higher oops

Glojo: I think I watched the same documentary as you - it drove me up the wall! Was it the one on how people can't tell the difference between tap and bottled water?

If so... (mini-rant time) They really need to stop their miseducation ploys! There is bottled water and bottled water. If you look at the label, there are "ratings" encoded in the wording...
- Natural Water/Cool Water/Bottled Drinking Water
- Spring Water
- Mineral Water / Natural Mineral Water

Needless to say, the lowest rating (bottled water) is pretty much bottled tap water... then comes spring water, which is barely better (it just means the water is extracted from a spring). At the highest level you have mineral/natural mineral water - which is untreated and has some other chemical properties im unsure of...

Now, I'm not sure if these hold in English, but in Italian it's actually a legal requirement for the company bottling the water to identify the type of water. You cannot bottle tap water and call it mineral water (or vice versa).

So, when the documentary/adutary says "oh bottled water tastes like tap water" it really drives me up the wall....

There; rant over...

Michele

 

[oldcro]

I'm not sure about the cooling rates of tap via bottled water, but I filled a kettle with tap water and put it on the stove. I watched the kettle and the water never boiled.

 

[crockers]

Why are you making tea with tap water? YUK.................

 

[glojo]

Glojo: I think I watched the same documentary as you - it drove me up the wall! Was it the one on how people can't tell the difference between tap and bottled water?

Hi Michele,
I'm afraid I cannot remember what the title was, but when we first moved to Torquay my wife went to the local hardware store to ask for some de-scalent. The shop owner simply looked at my wife with a blanl expression!!! Here is Douth Devon, a kettle will rust long before it collect any type of lime etc. I also have to add water hardning chemicals to our swimming pool water to prevent the grout from being 'eaten'

Here is a BBC link

Tap water is pure, and that's theopinion of the drinking water inspectorate, which carries out three million checks a year!

I tend to think that drinking bottled water is like congratulating the emperor on his new suit, but power to the elbow for folks that buy water just to drink it.

Regards
John the 'I drink tap water man'

 

[230K]

John

Be assured that the 230k family drink tap water tea, its just a marina we pulled in at had the most horrible water and we tried bottled water. Also if we forget to fill the kettle before leaving port we have to resort to bottled water. i wouldnt chance the water in the fresh water tank for anything other than washing.

Has anyone noticed that bottled water cools quicker or are we just imagining things????

The joys of holidaying!!

230k

 

[glojo]

John

Be assured that the 230k family drink tap water tea, its just a marina we pulled in at had the most horrible water and we tried bottled water. Also if we forget to fill the kettle before leaving port we have to resort to bottled water. i wouldnt chance the water in the fresh water tank for anything other than washing.

Has anyone noticed that bottled water cools quicker or are we just imagining things????

The joys of holidaying!!

230k

I take it you have bought your boat????? I'm going green with envy.

Don't bother buying bottled water rubbish

Fit this into your cruiser.... You'll be able to go on that World cruise without a single care in the World

I love spending other peoples money

 

[Brian WH]

Perhaps this will help.

Boiling Water Myths

 

[Howard]

Why wouldn't you chance the water in the tanks ?

Should be stainless tanks .... if it has been standing for a while , flush them through ...

 

[stevesey]

Perhaps this will help.

Boiling Water Myths

Hm - says adding salt raises the boiling point and the (single) experiment backed this up (as does a bit of googling).

 

[gina2201]

Maybe you added more (cold) milk by accident!

 

[DITTRICH]

P11 Hot water may freeze faster than cold water; the Mpemba effect
The ability of hot water to freeze faster than cold seems counter-intuitive as it would seem that hot water must first become cold water and therefore the time required for this will always delay its freezing relative to cold water. However experiments show that hot water (for example, 90 °C) does often (but by no means always) appear to freeze faster than the same amount of cold water (for example, 18°C) under otherwise identical conditions [158]. This has been recognized even as far back as Aristotle in the 4th century BC but was brought to the attention of the scientific community by the perseverance of Erasto Mpemba [1388] a Tanzanian schoolboy,c who refused to reject his own evidence, or bow to disbelieving mockery, that he could freeze ice cream faster if he warmed it first. For a recent review of the Mpemba effect, see [959].






A number of explanations have been put forward. One that has gained some support is that there is sufficient evaporation from the hot water that this causes faster cooling plus a reduction in mass, so faster freezing [1390]. There does not seem to be sufficient mass lost in experiments to support such an explanation as the sole cause, however, and the effect is apparent even when the vessel has a lid. Related to this explanation, part of the cause may be due to the larger and more persistent convective currents created when hot water cools; however the effect is again evident even if the vessel has an insulated base and lid. The most likely scenario (described in [158], but disputed [1415].) is that the degree of supercooling is greater, under some circumstances, in initially-cold water than initially-hot water. The initially-hot water appears to freeze at a higher temperature (less supercooling) but less of the apparently frozen ice is solid and a considerable amount is trapped liquid water. Initially-cold water freezes at a lower temperature to a more completely solid ice with less included liquid water; the lower temperature causing intensive nucleation and a faster crystal growth rate. If the freezing temperature is kept about -6°C then the initially-hot water is most likely to (apparently) freeze first. If freezing is continued, initially-cold water always completely freezes before initially-hot water.



Why initially-cold water supercools more is explained in terms of the gas concentration and the clustering of water. Icosahedral clusters do not readily allow the necessary arrangement of water molecules to enable hexagonal ice crystal initiation; such clustering is the cause of the facile supercooling of water. Water that is initially-cold will have the maximum (equilibrium) concentration of such icosahedral clustering. Initially-hot water has lost much of its ordered clustering and, if the cooling time is sufficiently short, this will not be fully re-attained before freezing. Experiments on low-density water around macromolecules have shown that such clustering processes may take some time [4]. Also of relevance here is that the formation of clathrate ices, which have structures closely related to the icosahedral clusters, behaves in an opposite manner. Thus, the supercooling from hot water is far greater than that from cold water [1391].



It is also possible that dissolved gases may encourage supercooling by (1) increasing the degree of structuring, by hydrophobic hydration, in the previously-cold water relative to the gas-reduced previously-hot water (the critical effect of low concentrations of dissolved gas on water structure is reported in [294]; re-equilibration taking several days) and (2) increasing the pressure as gas comes out of solution when the water starts to crystallize, so lowering the melting point and reducing the tendency to freeze (see guest book). Also, the presence of tiny gas bubbles (cavities produced on heating) may increase the rate of nucleation, so reducing supercooling [428]. Recently another possibility has been described depending on changes in dissolved material with temperature (such as the reduction in bicarbonate in heated 'hard' water), but this has not yet been experimentally tested [1014]. The rationale for the Mpemba effect in this case concerns differences in the solute concentration at the ice-liquid interface causing a localized lowering of the melting point [1014]. [ Anomalies page : Back to Top ]