46
votes
Why isn't 'chemically-strengthened glass' made with potassium carbonate to begin with?
The potassium is not added first because the potassium does not intrinsically make stronger glass, it is the substitution of a larger ion for a smaller one at the surface that does.
To understand why ...
- 12.4k
26
votes
Why isn't 'chemically-strengthened glass' made with potassium carbonate to begin with?
Chemically-strengthened glass is similar tempered glass in that the outside of the glass is under compression, while the inside is not compressed. If all the sodium in chemically-strengthened glass ...
- 30.5k
21
votes
Accepted
What makes Gorilla Glass more durable with each generation?
Are there other ways of "chemical strengthening" besides cationic exchange that can be utilized to strengthen the glass, keeping it flexible and less fragile at the same time?
In a word: No.
To ...
- 12.4k
18
votes
Can glass be deionized?
You can indeed "harden" glass by exchanging ions on the surface, but not because it turns into quartz glass.
Quartz glass is mostly so robust because it has an extremely small thermal expansion ...
- 12k
13
votes
Melting point of obsidian
Obsidian
This is a volcanic glass, formed when rhyolitic lavas cool too quickly for crystals to form. From a chemistry point of view, it's a mixture of silicon dioxide, aluminium oxide, with sodium ,...
- 231
12
votes
Accepted
Why is xenon hexafluoride not stored in glass?
$\ce{XeF_6}$ can't be stored in glass as it reacts with the silica that makes up the glass
$\ce{2XeF_6 + SiO_2 -> 2XeOF_4 + SiF_4}$
This can proceed further to eventfully make $\ce{XeO_3}$:
$\ce{...
- 2,950
11
votes
How to identify a blow-out pipette?
Good to see classical analytical chemistry queries. These graduated pipettes or Mohr pipettes they are called, confuse even the relatively advanced users. First you have to check where the graduations ...
- 39.1k
9
votes
Can olivine be used to make glass?
You could proceed from either end member of the olivine solid series and yield $\ce{SiO2}$ as you suggest.
However, I'd consider mechanisms that have been researched in the course of studying so-...
- 10.6k
8
votes
Accepted
What home products are reactive with glass?
Some rust and stain removers (like Whink) contain hydrofluoric acid* at low concentrations (1-2.3%) Here is the MSDS for Whink: https://www.whink.com/cmssites/ws0811www.whink.com/uploads/Documents/...
- 605
8
votes
Does crystalline glass exist?
As Ivan explained, a glass is by definition amorphous. However, you can take a quartz crystal (silicon dioxide, which is the main ingredient of glass) if it is of high purity and optical quality, and ...
- 9,216
8
votes
Accepted
Gold Plating on Glass?
Gold plating glass could probably be 99.99% complete. It would make a nice mirror and would probably stay unoxidized for a long time.
However, if I wanted to remove the gold, I think I would rinse ...
- 13.9k
7
votes
What makes Gorilla Glass more durable with each generation?
To really answer this, you need to characterize the glass in terms of its properties, and not something like its ability to resist being scratched. Scratch resistance is a behaviour, and not a ...
- 244
7
votes
Accepted
Why does automotive glass shatter into tiny pieces but glass used in our houses into shards?
Let's start out by covering the
Why?
Glasses used in automobiles are designed to break in tiny pieces.
Imagine you're driving down a dark highway hitting dangerously high speeds and then suddenly you ...
- 5,504
7
votes
Accepted
What is wrong with storing deionized water in glass containers?
It is very difficult to make a container that does not introduce impurities to a liquid you place into it. As mentioned in the comments to the question, storing in a glass bottle will result in ions ...
- 39.1k
7
votes
Accepted
Understanding the molar free energy to simulate phase separations (Na2O-SiO2)
In an Ideal solution, based on how many ways one can randomly arrange the constituents, one gets:
$\Delta S_{mix} = -R(X_{A} \ln{X_{A}} + X_{B} \ln{X_{B}})$ with $X_{A}+X_{B} = 1$ being the relative ...
- 8,349
6
votes
Can glass be made with anorthite?
In theory, yes it is possible. In practice, not really.
First of all, the anorthite on the moon is never pure anorthite ($\ce{CaAl2Si2O8}$) but rather an anorthite-albite ($\ce{NaAlSi3O8}$) solid ...
- 5,214
6
votes
Why isn't 'chemically-strengthened glass' made with potassium carbonate to begin with?
As A.K. notes, it is the substitution of larger atoms for smaller atoms that adds stress to the glass, making it stronger. So you can't increase the stress by starting with a larger metal, but you ...
- 61
6
votes
Accepted
What reaction could rubidium undergo in a vacuumed chamber with Macor ceramic and glass?
One candidate for reaction with the rubidium is silica, $\ce{SiO2}$. Reference [1] reports that black powders are formed when alkali metals are contacted with silica. Such powders are more stable in ...
- 53.3k
6
votes
Can glass be deionized?
You could dealkalize the surface of a borosilicate glass to get rid of alkali ions, but I'm not aware of a method that allowed the extraction of alkali metals from the bulk of the glass.
There are ...
- 733
6
votes
How to identify a blow-out pipette?
Elsewhere here, M. Farooq has given excellent answer for this analytical chemistry question. I like to explore this answer by explaining what are these lines means and some confusions arose from M. ...
- 39.5k
5
votes
Accepted
Can hydrofluoric acid etch glass at a pH of 7.0?
In $\ce{SiO2}$ etching, there are two active fluorine-containing species, $\ce{HF}$ and $\ce{HF2-}$.
The rate of etching at 25 degrees C in Angstroms per second is:
$$9.66[\ce{HF2-}] + 2.50 [\ce{HF}]...
- 40.3k
5
votes
Accepted
Can olivine be used to make glass?
The previous answer is not really helpful because you would need huge amounts of CO2 which are not available on the moon. You need 2 moles of CO2 to generate 1 moles of SiO2. You simply do not have ...
- 5,214
5
votes
Carbon in Glass - XPS Analysis
Well, XPS analysis should detect atoms as light as Carbon, but not atoms as light as Hydrogen.
Far be it from me to claim any expertise on microscope sliders, but I have used one or two in my career, ...
- 2,747
5
votes
How should you report measurements and uncertainty for a measuring cylinder with 0.5 mL graduations?
common convention is to report the uncertainty of an analogue
instrument as plus or minus half of the smallest scale division
Yes, this is merely a poor convention propagated by general chemistry ...
- 39.1k
4
votes
Is the surface of glass a fine layer of silanol?
Yes, it is correct that the surface of glass has silanol ($\ce{Si-O-H}$) at the surface. This is because water will react at the surface to relieve bond strain of a $\ce{Si-O-Si}$ bond to form $\ce{Si-...
- 12.4k
4
votes
How does lime prevent soda lime glass from dissolving in water?
The addition of lime does indeed form calcium silicate, but it doesn't serve the purpose you mentioned. Silica of itself isn't water soluble, nor soda glass.
The difference is in the crystalline ...
- 382
4
votes
Accepted
Cold process to make glass
Not glass per se, but silica is often produced chemically by silicon alkoxide gelation to create aerogels.
The problem with creating glass by some cold process would be that the reaction side-...
- 30.5k
4
votes
Accepted
Can you measure an IR spectrum of a sample inside a glass vial?
As EdV said, when you have aqueous samples, Raman spectroscopy is the way to go. The problem is not the container (which should not be glass etc),the problem is water. Its absorption will hide the ...
- 39.1k
4
votes
Are diamonds as chemically inert as glass?
Diamonds are chemically inert. They burn at very high temperatures, but apart from this, they don't react. They are insoluble in all sorts of solvents, with the exceptions of iron above its melting ...
- 27.1k
4
votes
Accepted
Can any compound form into an amorphous solid?
Whether a substance crystallizes or not largely depends on the rate of cooling or loss of solvent.
K. Gibson states, "Cooling materials super-quickly... prevents the normal crystalline ...
- 30.5k
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