Questions tagged [water]

For questions relating to water (H₂O), specifically its structure, properties, and uses in chemistry. For questions not about water but rather about solutions in water, use tags [aqueous-solution] or [solubility] instead.

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Homework - Water evaporation in a sealed container with vacuum [closed]

Let's say I have a container where I extract the air and create a near perfect vacuum. The volume of the container is 100 m^3 In the container there is a large bottle (made of glass) which is filled ...
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2answers
47 views

Equation of water at triple point

I was thinking about what exactly happens at the triple point of water, and what could be the effect of adding solutes/solvents. I feel we can represent the triple point using the following ...
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Does ice increase the humidity of its surroundings? [closed]

Does ice increase the humidity of its surroundings? I'm trying to use the BME280 for an Arduino project regarding locating ice, but I don't know whether the atmosphere is more humid around ice. I'm ...
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44 views

Is it more energy efficient to desalinate seawater by flash boiling or by flash freezing? [closed]

In Saudi Arabia I think there are two types of desalination using flash boiling from electric power production and also from flash freezing using solar absorption refrigerant freezing. One requires ...
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Is OH– a weak base or a strong base? [closed]

From my point of view, $\ce{OH–}$ should have been a very good base, but in my copy, it is written that $\ce{OH–}$ is a weak base. All the articles that I can find on the internet do nothing but ...
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1answer
21 views

Using charcoal to clean water [closed]

I have read about charcoal being used to clean water before it is then boiled or mixed with a UV light stick. I have some questions about this: 1) Does it have to be activated charcoal? 2) Can ...
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11 views

Electrolysis of water and Gibbs Energy

I'm writing a chemical equilibrium program which minimizes the Gibbs energy. The program accepts as input the total amounts of the elements comprising the system, and a list of possible molecular ...
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1answer
36 views

Is there a temperature where salt doesn't dissolve in water?

I know that salt dissolving in water is driven mostly by entropy. However, at lower temperatures, entropy is less of a factor in controlling reactions. Is there a temperature where salt doesn't ...
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2answers
76 views

Does water in big cities get heated (boiled) for treatment?

I live in Bangkok and read how water comes to customers here: I understand from the chart that water go through Thon Buri treatment plant (west Bangkok) and Mahasawat treatment plant (east Bangkok) ...
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3answers
72 views

Tap water pH adjustment using citric acid

I've lowered tap water pH from 7 to 6 using citric acid. After couple of hours pH raised again to 7. What is the reason for this raise? Citric acid overcomes waters buffering feature then raise the $...
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1answer
31 views

What formula allows adjusting balance of (Ethyl Alcohol / Water / Caffeine powder) to know concentration for the Caffeine solution?

I am experimenting with different levels of concentrated caffeine solution. The solution has a small percentage of ethyl alcohol, in the $\ce{H2O}$. Problems encountered too much ethyl alcohol ...
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1answer
32 views

Copper wire smoking underwater [closed]

I am doing an electrolysis experiment with two copper wires inside of test tubes that are both submerged underwater, with 20 V per wire. Test tube A is creating oxygen gas at a high rate, but test ...
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Method to find out the amount of solvent replaced by another solvent

So I am performing a relatively simple coprecipitation experiment to synthesize ceramics. All my precursors are in aqueous solutions. But due to the high surface tension of water, drying the water is ...
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Thermal decomposition of steam to hydrogen and oxygen; at what temperature is half decomposed and how to calculate?

In comments below this answer in Space Exploration SE I've said: (Wikipedia) says that dissociating water costs about 4.4 eV per bond. If 𝑘𝐵𝑇= 4.4 eV and $k_B$ is 8.617E-05 eV/K then that ...
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Ionic content of different samples of water

So I was reading about impurities of in water and I have a question in mind: So say we have Distilled Water , Deionized Water , Tap Water and Soft water which was softening using dowex resin or any ...
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1answer
55 views

Precipitation of water-insoluble materials from shower or laundry greywater

I am currently working on a project to build a filter that aims to separate or salt out the 'dirt' in shower or laundry greywater. The ideal result from this chemical reaction will be such that the '...
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1answer
34 views

Order of magnitude of ions in water [closed]

My book says water has approximately $\pu{3.35E28 molecules/m^3}$ and that only a small part of water molecules are dissociated to $\ce{H+}$ and $\ce{OH-}$ ions and that the approximate amount of ...
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1answer
180 views

How to dispose of NaOH solution? [closed]

I have a range of sodium hydroxide solutions with different concentrations. (from 1.0 mol dm^-3 to 0.5 mol dm^-3). The max volume of each is 100ml. How can you easily dispose of these? Can I pour them ...
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42 views

How to calculate Revelle factor using only pH, DIC and TAlk for seawater?

I have the temperature, salinity, $\mathrm{pH},$ dissolved inorganic carbon (DIC) and total alkalinity (TAlk) values for an estuarine water sample. I want to calculate the Revelle factor. The Revelle ...
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1answer
30 views

Is an ion or a polar molecule more attracted to water in general? [closed]

I realize that there are exceptions but as a general rule of thumb, is an ion or a polar molecule attracted to water? I think that it would be ions since the charge is much larger than the net dipole ...
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2answers
63 views

Ratio of Water to Isopropyl Alcohol? [closed]

I am looking for a very simple formula to calculate the ratio of water to 99% isopropyl alcohol that I need to prepare a solution with a density of 0.925 g/cm3. I am assuming there is one.
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Could silica aerogel withdraw water from sulfuric acid?

Both silica aerogel and sulfuric acid have a hygroscopic nature. Which of the two is the strongest ? Could silica aerogel withdraw water even from concentrated sulfuric acid ?
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Factors affecting hardness of water - EDTA titration

I am thinking of doing a project involving EDTA complexometric titration to determine the hardness of the water. I am not sure if the pH will affect the hardness of the water. If it did, I would ...
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2answers
70 views

Finding pH of acid in water [closed]

How would you find the pH of an acid dissolved in water? Would you need to take the fact that the pH of water is already 7 into account and go on from there? Say, for example, that you add 0.0500 mL ...
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Why are wet things harder to ignite than dry things? [closed]

Specifically wood and paper and other hydrocarbons, but not necessarily excluding other things that burn. We all know wet wood is very hard to ignite. Wetness here refers to water. But why is that ...
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Liquid alternative to alcohol to lower density of water

I am trying to create a suspension of polypropylene particles in a water based liquid. I want the density of the liquid to be more than or equal to the density of polypropylene (855 - 946 kg/m3) so ...
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UK - Testing for Tap Water

Water is pooling in my garden next to my neighbour's fence. He has been harassing us in multiple ways for 8 years. It is the only place on my property where this is happening. It has never happened ...
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1answer
77 views

Boiling point elevation does not depend on the solute? [closed]

I've recently carried out an experiment trying to measure the boiling point elevation of water after adding 5M of NaCl and KCl. Although for some reason, KCl solution started boiling around 90 degree ...
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3answers
2k views

Are all volatile liquids combustible?

I realized that liquids like petrol, kerosene and even perfumes are combustible when they are volatile. Could that be the reason why water is not combustible is because it is not volatile? Are ...
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1answer
210 views

Why does boiled water have a different taste as compared to cool water? [closed]

I have noticed it frequently and decided to check with some of my peers and friends about this and they too have felt such a thing. The taste comparison occurs after the boiled water is cooled down to ...
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1answer
46 views

Combustion byproducts

I'm designing a system which will heat up water by burning natural gas which is commonly available. I would like to have a slow flame because water will need to reach 70 degrees C and stay there. ...
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1answer
367 views

Will charcoal briquettes (not activated) absorb water out of the air in the house in a subtropical climate?

I live in Florida, an incredibly wet environment where it's very difficult to get moisture out of house without using a dehumidifier 24/7, which is too expensive. Would charcoal briquettes be of any ...
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701 views

Is Phosphate (PO4 3-) solube in water? [closed]

Josh~ Superphosphate is used instead of just phosphate because superphosphate is a compound whereas phosphate is an ion. This means that phosphate must attach itself with a cation in order to give a ...
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4answers
269 views

Dissolving sand (or something similar) in a bottle of water?

I would like to create an illustration to demonstrate something during a talk. The idea goes that there is sediment in a bottle of water that sits at the bottom until shaken up then adding another ...
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Does water really have strong EM absorption at 3 kHz in solid and 2 GHz in liquid? Why the huge shift?

While writing this answer to the question Transmitter receiver coil separation for Electromagnetic Terrain Conductivity Measurement I ran across this large PDF file of a book Soil and Environmental ...
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1answer
61 views

Can the light reaction of photosynthesis happen spontaneous in pools of water?

I've just learnt that a part of the photosynthesis reaction is the light reaction, where sunlight is absorbed by chloroplasts, which then excites electrons to higher energy levels, allowing for water ...
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coffee concentrate and water separated after 2 hours. How/why?

I'm asking because this makes no sense to me and making sure I'm not stupid. I brewed 10 gallons of cold brew concentrate(TDS 12.2) and mixed it with 10 gallons of water. I moved 10 gallons of the ...
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1answer
63 views

Will sodium thiosulfate react with nitrate and/or nitrite ions [closed]

I am doing nitrate and nitrite quantification in raw water and treated water using a colorimetric method. The manufacturer of the instrument states that water with chloride will interfere with the ...
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2answers
68 views

Metering Device decreases pressure yet produces saturated liquid?

This question pertains to the change of state of liquid using a Metering Device as the refrigerant enters an Evaporator Coil of an HVAC system: The Metering Device takes liquid and then reduces the ...
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Issue with evaporation rate of water

The evaporation rate of water (kg/s) is given by: $$g = \frac{P}{P_o} AΘ$$ Where $P$ is given in Pascals and $A$ is the surface area (in $m^2$) and $Θ$ is the empirical evaporation ...
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1answer
63 views

Temperature and pressure for three phase equilibrium of aqueous sodium chloride solutions

I am currently investigating the effect of adding Salt(NaCl) to water on its triple point. Let us assume the mass ratio of water to NaCl is $1:1$. I asked a similar question previously. But, I still ...
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28 views

How do you remove lumps in reagents without contaminating them?

I think desiccating the powdered reagent would help remove lumps (at least in preventing lump neoformation) but would desiccation alone collapse all lumps in a powder (say KCl as it lumps easily), or ...
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2answers
123 views

Does adding solutes to water alter its triple point? [closed]

Does adding solutes to water alter its triple point? If yes, how do we find the new temperature and pressure of this point?
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1answer
449 views

Reaction of potassium with water

In general, when we put potassium into water, it will produce potassium hydroxide and hydrogen: $\ce{2K + 2H2O ⟶2KOH + H2}$ However isn't the following reaction also possible? $\ce{2K + H2O ⟶K2O + ...
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3answers
217 views

If carbon dioxide is non polar, why does it react with water?

I’ve read in many places that carbon dioxide forms carbonic acid with water since the carbon is partially positive and thus the oxygen bonds with it. But isn’t carbon dioxide in its entirety non polar ...
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1answer
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Why does H2O electrolysis produce O2 on the anode instead of H2O2

If the oxidation of $\ce{H2O}$ produces $\ce{OH-}$ ions and the anode separates electrons from them leaving neutral $\ce{OH}$ molecules, why don't they bind to each other covalently?
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1answer
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Mechanism of burning of hydrogen [duplicate]

So I was curious regarding a simple chemical equation : $$\ce{2 H2 + O2 -> 2 H2O}$$ You add heat to the system (i.e fire) and you get water vapor. I'm curious of understanding the mechanism, ...
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Can caustic soda (sodium hydroxide) be used to dissolve urine odour?

I have an area of artificial grass at home in the back garden and during the summer months, the area emits a smell which I can only think is from the dog's urine when he pees all year long. The smell ...
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103 views

What would superionic water ice look like?

Phys.org's Giant lasers crystallize water with shockwaves, revealing the atomic structure of superionic ice links to Nature Physics: Experimental evidence for superionic water ice using shock ...
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Is it possible to raise pH in RO water without Na, Mg, K, Ca, S addition?

Maybe the question in the title is simple (=stupid) and the answer is 'simple No' but I have the urge to ask. Some background, I have an aquarium which I use RO water and I use some portions of $\ce{...