For questions relating to water (H2O), specifically its structure, properties, and uses in chemistry.

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14
votes
2answers
836 views

Why is snow white?

I know that this is a rather ambiguous question; but my question is, whenever we take water and freeze it in the freezer it tends to still stay clear. Since snow is just frozen water, why is it white? ...
4
votes
1answer
23 views

Pre heat coal before burning

So I was wondering if pre-heating coal will improve the efficiency of a steam boiler. I did find that intake air pre-heater and water pre-heater do increase efficiency, but I could not find anything ...
2
votes
1answer
34 views

Can someone induce cancer in another person

Is it possible to poison someone's food on a daily basis in order to give them cancer? The thing here is that i'm worried someone at my workplace might be poisoning other people's water (each ...
4
votes
1answer
25 views

Boiling aluminum in high-alkalinity water

This question ultimately relates to brewing beer, but more specifically to water treatment before brewing. Though I can't get a water quality report, I suspect I have high levels of bicarbonate ...
5
votes
2answers
47 views

What allows all 3 states of H₂O to be present at the same time?

How is it possible for there to be a glacier floating on water but under clouds? Depending on the temperature, shouldn't there only be one state of water?
0
votes
1answer
31 views

Can water electrolysis detect the water impurities?

A salesman came to my house to demonstrate his water purifier machine which is a RO Purifier. To show the difference between his purifier machine and the machine I own, he took some water from my ...
2
votes
1answer
33 views

Is there any abbreviation for hydrates?

I'm getting tired of writing out the full formulas for hydrates, adding $\ce{.$x$\,H2O}$ to all formulas. I'm wondering if there's standard shorthand for these.
4
votes
2answers
37 views

Is water a better nucleophile than bromide?

I am a student of biochemistry. My organic chemistry professor was giving a lecture and he talked about halohydrin formation reactions. At one point, he said that "water attacks instead of bromide ...
4
votes
2answers
178 views

Solubility of Noble Gases

I read this statement that " Xenon is the most soluble noble gas in water " . My first doubt is , Why does the solubility of noble gases in water increase down the group ? Even if this is the ...
11
votes
7answers
5k views

How can 30 ml of water be heated in less than 10 seconds?

How is it possible to heat a tiny amount (30 ml)[1] of water to a high enough temperature to make a coffee, in less than 10 seconds and possibly instantly? Most heaters that I know of heat water ...
2
votes
1answer
38 views

Why don't water molecules react alongside aqueous reactions?

To explain my question I'll use an example: We all know that sodium displaces copper in a solution of its sulfate in the reaction: $$\ce{2Na (s) + CuSO4 (aq) \rightarrow Na2SO4 (aq) + Cu (s)}$$ My ...
4
votes
1answer
30 views

Does the boiling boint of miscible liquids follow a linear relationship?

I want to create a steam bath for a reaction the proceeds well at 105℃. I cannot use pure (demineralized, anyway) water for this, since it would boil at 100℃ at STP. As such I figured ...
2
votes
1answer
101 views

How to RAISE the melting point of water?

It is common that adding common salt into water will lower its melting point. But, is there any way to RAISE the melting point of water? Does it lower the boiling point of water as well? Why?
2
votes
1answer
29 views

What is the smell of a glass of water in contact with fresh air?

When you pour water into a clean glass in a small confined room with no or little fresh air circulation, the only smells you perceive are those of the glass and the water (or the impurities from both ...
3
votes
2answers
83 views

Can artificial sea water be prepared by mixing sea salt with water?

I am looking for ways to easily prepare artificial sea water. The chemical composition doesn't have to exactly match that of natural sea water. On-line I can find recipes to prepare sea water. But I ...
3
votes
2answers
53 views

What is hard and soft water and how does the process of dissolution work?

This is a very basic question about solubility, especially solution of table salt in water and solution of sugar in water. I have heard about terms like hard water, soft water, filtering of water to ...
1
vote
2answers
53 views

Are Na and Cl ions from NaCl in water separate charged particles?

Suppose I pour some sodium chlorine into water. So, what happens is that NaCl(s) → Na+(aq) + Cl-(aq) meaning that the ionic bond between Na and Cl breaks up (correct this far?) Now, does this mean ...
4
votes
3answers
247 views

Why is oxygenated water not H2O2?

Oxygenated water has become popular for a variety of uses recently - for health purposes internally as well as enhanced wound healing. Anyhow, my dad asked me recently if I knew how it is that ...
1
vote
0answers
33 views

Why is water considered ionic in fuel cells but otherwise covalent?

if water (H2O) is a Covalent compound formed by sharing of electrons, why is it said (in case of fuel cells) that formation of water from hydrogen and oxygen is a redox reaction (transfer of ...
1
vote
1answer
40 views

Hydrolysis - How do I know which atoms react?

In the hydrolysis of Propanamide ($\ce{CH3CH2CONH2}$) how do I know which molecules react with the water? $$\ce{CH3CH2CONH2 + H2O \rightarrow ?}$$ I don't know how to split the molecule. In the ...
0
votes
0answers
36 views

Aluminium in Active Carbon Water Filters

So I saw on article stating concerns about eating active carbon due to high levels of aluminium found, would this have implications with active carbon water filters? Or would the aluminium not get ...
0
votes
1answer
27 views

How to purify water with activated carbon?

If I am not mistaken, distilling water does not remove all possible impurities. Chemicals with boiling points less than $100 ° C$ will be transferred as well. Does the usual tap water contain such (I ...
0
votes
2answers
47 views

Can plastic leak into water from a HDPE “2” plastic container at room temperature?

Here in USA supermarkets often sell water in plastic 1 gallon jugs. These jugs seem to all be stamped with the text "HDPE" (meaning that the material is High-density polyethylene) and a resin number ...
3
votes
2answers
44 views

Structures present in liquid water

I know this may be a too generic question, but here it goes anyway. It is already know that solid water (ice) organizes its molecules in a lattice (in a variety of 16 different crystals and one ...
5
votes
1answer
45 views

The sponge isn't foaming up, why?

When I add dish soap to a sponge it is able to foam up. But if I leave the sponge alone for an hour, it doesn't foam up, not even if it is wetted. Why? The sponge should still contain dish soap an ...
6
votes
1answer
73 views

What is the white substance left behind after boiling down water

I was boiling down water in a stainless steel pot as an experiment the other day. When the water was completely vaporised, a white substance was left behind on the bottom of the pot. I tried rubbing ...
2
votes
1answer
29 views

What determines humidity limit / dew point of the air? - Why can air only hold a certain amount of water?

From Wikipedia: The dew point is the temperature at which the water vapor in a sample of air at constant barometric pressure condenses into liquid water at the same rate at which it evaporates. At ...
3
votes
1answer
13 views

Why don't sponges foam up an hour later?

When I add dish soap to a sponge it is able to foam up. But if I leave the sponge alone for an hour, it doesn't foam up, not even if it is wetted. Why? The sponge should still contain dish soap an ...
4
votes
2answers
291 views

Why does water change phase so easily?

I did some undergraduate level Chemistry as part of my degree. It left me with the distinct impression that the polarity of water is responsible for its unusual phase properties: it's the only ...
1
vote
0answers
75 views

What compound can give off heat when it comes in contact with ice?

What compound is able to produce heat when it comes in contact with ice? The compound has to be able to produce heat multiple times. I was thinking of a compound that is similar to Calcium Chloride. ...
0
votes
3answers
66 views

Thought Experiment on Boiling

In this thought experiment, let’s consider the surrounding to be air that is composed of entirely water vapor (no other species like $\ce{O2}$ and $\ce{N2}$ are present). The surrounding is infinitely ...
0
votes
1answer
48 views

ph & pOH - Autoionization of Water

So I was learning about pH and pOH and it made sense. I looked at strong, weak acids & bases and learned that they dissociate completely in water. So then I moved on to water and learned about the ...
0
votes
2answers
84 views

How does this method of calculating the water equivalent of a calorimeter work?

I am doing a AP Chemistry lab in which we determine the heat capacity of a calorimeter (a concept that seems like it should depend on a lot more than just the calorimeter.) We have to calorimeters ...
4
votes
1answer
632 views

Drying Clothes Outside Below Freezing

It is commonly accepted that you can hang your wet clothes outside to dry even when the winter temperature is below freezing. It is mentioned here ...
2
votes
1answer
70 views

Volume of 1 Mole of Liquid Water

I am doing some rough calculations to test my understanding of elementary chemistry. In what follows, I calculate the volume of one mole of liquid water at about $4~^\circ\mathrm{C}$ and ...
1
vote
1answer
33 views

How can concrete set underwater?

I'm about to teach concrete to some high school children. I'm not a chemist but as I understand it the limestone cycle is this: ...
0
votes
1answer
36 views

Chemical Composition Changes in Liquids

Water is $\ce{H2O}$ in all it's states: solid(ice), liquid, and gas(water vapor). In your drink, when you add artificial flavoring and coloring, does it change the chemical composition of the water? ...
1
vote
1answer
48 views

If hydrogen bonding in water was weaker, what happens to H+ ion concentration?

Water ionization becomes much less evident if the hydrogen bonds are just a few percent stronger but pure water contains considerably more $\ce{H+}$ ions if they are few percent weaker. I found ...
2
votes
2answers
63 views

Reuse 20 litre plastic drums for drinking water?

Would you consider it safe to clean and reuse a 20 litre plastic drum that contained 36% Hydrochloric Acid for drinking water? If so how would you recommend cleaning it?
3
votes
1answer
65 views

what would happen if you got a full package of wet silica gel on your hand after it tore open? [closed]

I accidently opened a bag of silica gel and got it on my hand what will happen to my hand because now it kinda feels weird.
2
votes
1answer
53 views

Does the density of a liquid and gas phase of a substance(nitrogen or water) converge when reaching critical point

I know that the there is no difference in density in a liquid and a gas phase of a substance after the critical point. But I do want to know if this difference in density is more continuous or if it ...
2
votes
1answer
157 views

Boil to dry 50 litres water

I would like to find out how long it would take to completely turn 50 litres of water to steam. Let's assume power of 2500 W and the water is already at boil. I am not very scientific so please ...
2
votes
1answer
68 views

Density of water and temperature

Is there a formula that shows how the density of water is affected by temperature? For example, with the speed of sound it can be shown how temperature will affect the speed: $$V = 331\ ...
0
votes
2answers
81 views

Hydrogen peroxide from water

Is it possible that $\ce{2 OH-}$ from water could react to form $\ce{H2O2}$? I mean most autoionization forms $\ce{H3O+}$ and $\ce{OH-}$. However I think it is possible that $\ce{H-}$ and $\ce{OH+}$ ...
2
votes
2answers
52 views

Same monomers, different water content?

We're currently studying "the chemistry of contact lenses", which is mostly polymers and gels. I just looked at the package of two pure hydrogel lenses made out of the same monomers, but they have ...
12
votes
5answers
3k views

Why is water “the universal” solvent?

An old question that our textbook tried to answer but worsened the situation. Many things are soluble in water. So many, that studying solutions will always require studying aqueous ones. It is true ...
3
votes
0answers
81 views

Why do some solid chemicals dissolve better in colder water?

I just discovered that some solid chemicals, such as $\ce{Na2SO4}$, dissolve better in cold water than hot water from here and would like to know if there is any particular reason as to why. Is it ...
1
vote
0answers
17 views

Is there a substance that would react with seawater to produce a dense, insoluble, nonporous precipitate?

Is there a substance that would react with seawater to produce a dense, insoluble, nonporous precipitate? Alternatively, is there a hygroscopic substance that will absorb water and expand into a ...
5
votes
3answers
999 views

Why isn't water an ionic compound?

If two alkali metal atoms join with an oxygen atom, an ionic bond forms. Since hydrogen has the same number of valence electrons as alkali metals, why can't water be ionic? This is what I'm ...
3
votes
0answers
45 views

Is Sweetwater, Missouri, named due to water contamination with lead compounds?

Sweetwater Missouri is known for it's mineral resources, particularly rich lead sulphide (galena) deposits. I was curious to find the origin of the name 'Sweetwater' and if it had any connection with ...