instruction stringlengths 15 21.8k |
|---|
[**Water**](http://www.sciencelab.com/msds.php?msdsId=9927321)!
![Water MSDS][1]
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[](xxxx)
[1]: https://i.stack.imgur.com/uH6Ix.png |
[**Water**](http://www.sciencelab.com/msds.php?msdsId=9927321)!
![Water MSDS][1]
---
You can find plenty of others if you perform [this search](http://en.wikipedia.org/w/index.php?search=%22NFPA-H+%3D+0%22+%22NFPA-F+%3D+0%22+NFPA-R+%3D+0%22&title=Special%3ASearch) in wikipedia (but then, go check the MSDS for ... |
I'm attempting to write a small program that will calculate the values for the Ideal Gas Law, specifically for molecular Hydrogen (H2) in space. Eventually, this will grow to be a sort of "simulator", but right now I seem to be having problems with remembering my college chemistry and physics.
Here is a picture of ... |
Why does the graph of $ln[A]$ vs $t$ produce a straight line for the first order rate law?
Also why does the graph of $t$ vs $\frac{1}{B}$ produce a straight line for the second order rate law? |
The binding of proteins to an ITO surface can be prevented by coating it with PEG groups (polyethylene glycol). PEG-silane is used to create the coating.
can somebody help with:
* Why does PEG silane bind to ITO (indiumtinoxide)? and how? (which bond etc.)
* Why does PEG repel proteins?
* Are there better... |
I just got a final test and one of the question is:
$\ce {Ni^2+}$ + 6$\ce{NH_3}$ $\ce {<=>}$ $\ce{[Ni(NH3)6]^2+}$
<br>If we add some aqueous $\ce{KOH}$ after the reaction reach equilibrium, where will the reaction shifts? |
If I add some KOH, where will the reaction shifts? |
I am working on an instruction manual of sorts to be used with an introductory course in thermodynamics. As an example of problem solving, I attempt to answer the following question:
> If you have little energy available, would you rather use an
> isothermal or an adiabatic process to compress a gas?
My analysi... |
I've been trying to find out about this for some time now and when I searched online, I couldn't get any solid reasons.
My question is: What is the reason for the characteristic colors of elements? For eg: Why does Sodium have a characteristic color of silvery-white?
Is there any solid reason for this? |
What is the reason behind the characteristic colors of elements? |
In crossed aldol condensation (condensation between aldehyde and a ketone), the primary products are such, that the carbonyl group of the ketone remains intact, and the $\alpha$-hydrogen of ketone participates, i.e. gets removed by the base to form the resonance stabilised nucleophilic [enolate][1] which later attacks ... |
Crossed aldol condensation products? |
The chemical structure of diamond is defined as an endless lattice in which each carbon atom is covalently bonded to four other carbon atoms at the four points of a tetrahedron. But of course they aren't endless; diamonds have edges and faces. So what happens when the lattice reaches the edge and there aren't any oth... |
What is the edge of a diamond like? |
> The reaction between p-methylbenzaldehyde and NaOH is an example of:
>
>
>
>
> A) cannizzaro reaction
>
>
>
>
> B) aldol condensation
>
>
>
>
>
> C)Hydrolysis
>
>
>
>
> D)Haloform reaction
I selected aldol condensation as the given compound is an aldeyde and it reacts wi... |
Cannizzaro or aldol condensation? |
What are the precise conditions under which Benzene undergoes ozonolysis? All anyone can tell me is that it undergoes ozonolysis under "vigorous" conditions. But, what vigorous conditions?
|
Sorry if this is not the place for asking this question, but I'm going to do a real life project and don't know where else to ask.
I'm going to prepare and sell snow cones next summer. For making snow cones, I was told by ice cone makers that ice should come from carbonated water.
As in my country is quite diffic... |
An aqueous solution of sodium hydrogen carbonate corrodes aluminum foil quite readily. How do you explain this? |
I'm trying to make a solution of TiO2 that will coat stuff in as dense a monolayer as possible. To do so, I'm using nano sized TiO2 particles and trying to get them to get as close to each other as possible. From what I understand, the way to get these little guys to get close to each other is to get the solution to ... |
The symbol from the periodic table for Potassium is "K". This fits my native language (dutch), where Potassium is called "Kalium". The same question applies to Sodium (Na), which again in Dutch is called "Natrium". A quick look at Wikipedia showed that Potassium is mainly used as a word in Roman based languages (French... |
Why is Potassium in French and English not called Kalium? |
My teacher taught about Rutherford's gold foil experiment today. Sir said that, Rutherford used gold foil of thickness $10^{-7}$ m and concluded atom to be of size $10^{-15}$ m. Sir also said that Rutherford assumed foil to be consisting of only single layer of gold atoms.
What I thought was, if Rutherford used... |
Wasn't Rutherford's assumption of gold foil to be made of single layer wrong? |
I'm supposed to balance a redox equation. I arrive at
$$
\ce{H2O} + \ce{NH4+} + 2\ce{S^{2-}} + \ce{O2} \rightarrow \ce{NH3} + 2\ce{S} + 3\ce{OH-}
$$
The "official" solution is
$$
4 \ce{NH4+} + 2\ce{S^{2-}} + \ce{O2} \rightarrow 4\ce{NH3} + 2\ce{S} + 2\ce{H2O}
$$
There is no information about if this is occ... |
Are these two reactions equivalent? |
My teacher taught about Rutherford's gold foil experiment today. Sir said that, Rutherford used gold foil of thickness $10^{-7}$ m and concluded atom to be of size $10^{-10}$ m. Sir also said that Rutherford assumed foil to be consisting of only single layer of gold atoms.
What I thought was, if Rutherford used... |
Let's start with the question: How do we get from your answer to the official answer? We can transform your answer into the official answer by first adding 3 ammonium ions to each side:
$\begin{aligned}\ce{H2O} + \ce{NH4+} + 2\ce{S^{2-}} + \ce{O2} & \rightarrow \ce{NH3} + 2\ce{S} + 3\ce{OH-} \\
+ 3 \ce{NH3}+3\ce{H... |
Motorola has a [device that is powered by stomach acid][1]. Given that a battery consumes the electrolyte as it generates a charge, how much power could be generated using a device such as this? Would the body just generate more acid to compensate? Would there be any physiological side-effects from using such a battery... |
How much electricity could be generated by a person's stomach acid? |
The chemical structure of a diamond is defined as an endless lattice in which each carbon atom is covalently bonded to four other carbon atoms situated at the four ends of a tetrahedron. But of course they aren't endless; diamonds have edges and faces. So what happens when the lattice reaches the edge and there aren'... |
Wikipedia has two different pages for [enthalpy of combustion][1] and [heat of combustion][2]. Their definition is the same and they use the same symbol $\Delta H_c^\circ $
It says that enthalpies of combustion are always negative as these reactions are exothermic. The heat of combustion tables list positive values ... |
What's the difference between enthalpy of combustion and heat of combustion? |
I'll preface this by saying I haven't had a chemistry class in 10 years and molecular structures are not my thing... But I'm submitting a revision to a journal paper where I need to include figures of molecules and I need to make sure I get it right so I don't get nit-picked apart for it.
Is there a standard/guide/... |
I'll preface this by saying I haven't had a chemistry class in 10 years and molecular structures are not my thing... But I'm submitting a revision to a journal paper where I need to include figures of molecules and I need to make sure I get it right so I don't get nit-picked apart for it.
Is there a standard/guide/... |
[Effective nuclear charge][1] is a very important concept in chemistry, and is the basis for the qualitative explanation of many observed chemical and physical properties, including several periodic trends. Hence it seems to me to be of significant importance that these values are accurately determined (not only for ne... |
Have there been no advances in the determination of effective nuclear charges since Clementi and Raimondi in the 60s? |
[Effective nuclear charge][1] is a very important concept in chemistry, and is the basis for the qualitative explanation of many observed chemical and physical properties, including several periodic trends. Hence it seems to me to be of significant importance that these values are accurately determined (not only for ne... |
I have yet to see an example of a molecule that's both polar and hydrophobic or that's both non-polar an hydrophilic. If no such molecule exists, why use the terms "hydrophilic" and "hydrophobic" at all if we can just refer to them as being polar or non-polar? If there are such molecules, what are some examples and why... |
Why distinguish between polarity and hydrophobicity? |
I'm studying the XRF method cause I'm about to use a WDXRF spectrometer at college so I'm getting all the information about the physics and chemistry behind it.
I'm just curious about one thing, as you know when a beam of x-ray hits the electron of an inner shell if the energy is just about lower than the electron b... |
X-ray fluorescence: where do expelled electrons go? |
Looking at Wikipedia for the definitions:
The **standard enthalpy of combustion** is the **enthalpy change** when **one mole of a reactant** completely burns in excess oxygen **under standard thermodynamic conditions** (although experimental values are usually obtained under different conditions and subsequently adj... |
Looking at Wikipedia for the definitions:
The **standard enthalpy of combustion** is the **enthalpy change** when **one mole of a reactant** completely burns in excess oxygen **under standard thermodynamic conditions** (although experimental values are usually obtained under different conditions and subsequently adj... |
In describing proteins, I've written "the proteins detached from the [Ni-IDA] matrix and **were eluted** from the column"
Should I use "were" or can something simply "elute" ? |
The proteins "eluted" or "were eluted"? |
A neat party trick (typically for outdoors) is to build a pyramid of tealights, let them burn for a while and then pour a bit of water over it and see a large jet flame shoot out (see e.g. [this youtube video][1]).
I was always told that this is caused by the water spreading the liquid wax out allow more of it to bu... |
Why does water cause a jet flame when poured over a bunch of tealights? |
A neat party trick (typically for outdoors) is to build a pyramid of tealights, let them burn for a while and then pour a bit of water over it and see a large jet flame shoot out (see e.g. [this youtube video][1]).
I was always told that this is caused by the water spreading the liquid wax out allow more of it to bu... |
I'm studying radioisotopes at the moment and balancing nuclear reactions isn't making sense in that more matter is coming out of the equation in negative β decay equations :
$^\textrm{14}_\textrm{6}\textrm{C}$ → $^\textrm{14}_\textrm{7}\textrm{N}$ + $\textrm{e}^\textrm{-}$ + $\textrm{v}^\textrm{-}_\textrm{e}$
No... |
In nuclear chemistry, how does a neutron split to form a proton and an electron? |
why should colorimetric titration of weak acid and weak base should not be done in laboratory?
Also how to draw the curve of weak base or Weak acid added and ph..??
|
why should colorimetric titration of weak acid and weak base should not be done in laboratory? |
A 15.8g strip of zinc metal was placed in 100ml of silver nitrate, When the reaction was complete, the strip of zinc had a mass of 13.1g. What was the concentration of the silver nitrate solution.
I am confused on writing the equation for this problem, because doesn't single displacement occur. So how can zinc meta... |
Quick run down, I was given pH of buffer 4.5 and then pKa of acid 4.79
I then had to work out volume of acid and volume of base using $\text{pH=pKa}+\log_{10}{\left(\dfrac{[\ce{A-}]}{[\ce{HA}]}\right)}$. Using that I calculated the volumes of acid and base required to make 15 ml of the buffer $\ce{CH3COOH,CH3COONa}... |
Let $\ce{R-OH}$ be a group with a $pK_a$ of 16. Are the following two statements correct?
- In principle, the group can protonate another acid with $pK_a > 16$, and so (put differently), any "acid" with $pK_a > 16$ can be used to "deprotonate" the group
- If I had a table with bases were only $pK_b$ values were g... |
So I was checking the structure of nitric acid in Wikipedia, however I couldn't quite fathom why it looked like that because it seemed to contradict the following statement:
> A Lewis structure with small or no formal charges is preferred over a Lewis structure with large formal charges.
![enter image description... |
Even though you may have a filled octet, if the central atom has a positive formal charge, we generally form double bonds until the formal charge is reduced to 0 as close as possible as that will be the more stable configuration. However, there are some exceptions.
Please take a look at the chlorate ion. For chlor... |
Even though you may have a filled octet, if the central atom has a positive formal charge, we generally form double bonds until the formal charge is reduced to 0 as close as possible as that will be the more stable configuration. However, there are some exceptions.
Please take a look at the chlorate ion. For chlorat... |
Where can one find examples of raw data for an 1H-NMR spectre ?
This is may sound as an odd request, so I'll give some context.
I have found lots of images of spectres such as ![enter image description here][1]
where you can see an image of the peaks. What I am interested is an spreadsheet
of the (x,y)-values u... |
Example of raw 1h-NMR data? |
Even though you may have a filled octet, if the central atom has a positive formal charge, we generally form double bonds until the formal charge is reduced to 0 as close as possible as that will be the more stable configuration. However, there are some exceptions.
Please take a look at the chlorate ion. For chlorat... |
Where can one find examples of raw data for an 1H-NMR spectre ?
This may sound as an odd request, so I'll give some context.
I have found lots of images of spectres such as ![enter image description here][1]
where you can see an image of the peaks. What I am interested is an spreadsheet
of the (x,y)-values used... |
a gaseous sample of a compound has a density of 0.977 g/L at 710.0 torr and 100.00C. What is the molar mass of this compound?
Please explain and show work. I want to understand it. when I worked the problem I got 29.9 g/mol is that right? |
Consider the following reaction : H2 + Cl2 -> 2HCl
A) if you have 15.00 liters of hydrogen reacting with 10.00 liters of chlorine at STP, how many liters of HCl would you produce?
B) What would be the limiting reagent?
C) how many moles of excess reagent would remain?
Please explain.
|
A sample of solid magnesium reacts with excess HCl solution to form hydrogen gas
The sample of gas measures 1.628 L at 22.0C and 0.930 atm pressure.
a) how many moles of gas were collected?
b) how many grams of magnesium did you start out with?
|
>A gaseous sample of a compound has a density of 0.977 g/L at 710.0 torr and 100.00C. What is the molar mass of this compound?
When I worked the problem I got 29.9 g/mol is that right? |
A sample of solid magnesium reacts with excess HCl solution to form hydrogen gas
The sample of gas measures 1.628 L at 22.0C and 0.930 atm pressure.
a) how many moles of gas were collected?
b) how many grams of magnesium did you start out with?
----------------------------------
First I stated by writing... |
Consider the following reaction : H2 + Cl2 -> 2HCl
A) if you have 15.00 liters of hydrogen reacting with 10.00 liters of chlorine at STP, how many liters of HCl would you produce?
B) What would be the limiting reagent?
C) how many moles of excess reagent would remain?
Please explain.
-------------
Molar... |
How many grams of oxygen are present at 25.0 C in a 5.00L tank of oxygen enriched air? The total pressure is 30.0 atm and the only other gas is nitrogen with a pressure of 17.0 atm.
After converting the temperature to Kalvin, I do not really know what to do.
How can I find the grams of oxygen with another molecule... |
A sample of solid magnesium reacts with excess HCl solution to form hydrogen gas
The sample of gas measures 1.628 L at 22.0C and 0.930 atm pressure.
a) how many moles of gas were collected?
b) how many grams of magnesium did you start out with?
----------------------------------
First I stated by writing... |
In the course of my undergraduate studies it has become clearer and clearer that it is quite helpful to know the ground electronic state of transition metals by heart, if only to speed up the process of analysing a reaction or to evaluate a compound in respect to its number of valence electrons.
I have now put the $... |
Today my teacher taught about amorphous and crystalline substances. Crystalline substances are said to have different values for physical properties (like speed of light, electrical resistance, etc) in different directions. Crystalline substances are said to have orderly arranged constituents, however this orderly arra... |
Why do amorphous substances have different values of physical properties in different directions? |
I am looking for a full set of data on every element on the periodic table. (and if possible those only speculated about)
When I say full I mean everything. Electron configurations, Valence electrons, melting point, Atomic mass, Isotopes and what they decay into and all the rest.
Is there such a database anywhere... |
I am reading a book which is saying about the Syn-Anti nomenclature of oximes. It is showing this molecule to be Syn-methyl-ethyl ketoxime.
![Syn-methyl-ethyl ketoxime][1]
[1]: https://i.stack.imgur.com/4rWxJ.png
I can't understand what is a ketoxime and how is there nomenclature done. Can somebody explain... |
What are ketoximes? |
An oxime is a chemical compound belonging to the imines, with the general formula R1 R2 C=N O H,
![enter image description here][1]
[1]: https://i.stack.imgur.com/byRLZ.png
How is the nomenclature of methyl-ethyl ketoxime done ? <br><br>
The answer is :<br>
Look at your photo .<br>
1-)On the left sid... |
In the course of my undergraduate studies it has become clearer and clearer that it is quite helpful to know the ground electronic state of transition metals by heart, if only to speed up the process of analysing a reaction or to evaluate a compound in respect to its number of valence electrons.
**Edit:** Note that... |
I am a bit confused about what chemical shift value signifies in proton NMR spectroscopy. If the proton of the standard substance TMS absorbs X Joules of energy to go into resonance, than a substance with a chemical shift value of 2.5ppm means it absorbs:
energy absorbed= X- (2.5X/10^6)?
Could someone please tell... |
I'm having trouble understanding how exactly coordination complexes are formed.
Compounds such as $\ce{[Cu(H2O)6]++}$ are the ligands filled into the empty 3 of 4p orbitals+ 1 of 5s orbital + 2 of 4d orbitals or how?
|
Formation of coordination complexes? |
I have a precipitation reaction of this form: Ca(2+) + CO3(2-) → CaCO3
How many mol of Ca(2+) ion is contained in a 200ml solution?
I'd like to know how to calculate this, thanks for the help! |
I have a precipitation reaction of this form:
$\ce{Ca^{2+} + CO_{3}^{2-} → CaCO3}$
How many mole of $\ce{Ca^{2+}}$ ion is contained in a 200ml solution?
I'd like to know how to calculate this, thanks for the help! |
Does the hydrogen ozonide exist? I mean if this compound could be found in Nature
$$HO_3$$
I am interested in the theoretical or phenomenological of such a chemical compound...
|
I was finding a more suitable site in Stack Exchange like Food and Beverages for this question, but there is no such site. I thought, on the other hand, that since water's composition is involved in my question, I decided to ask here rather. I will not be surprised if this question will be flagged as off-topic, though.... |
What is hydrogen-rich water? |
My question is: Is hydrogen-rich water true? I am aware of the alkaline water. I have read several articles in the Internet regarding this kind of water but I cannot seem to be convinced. Wikipedia isn't even talking about it.
I am puzzled with how can a water be enriched with hydrogen. It's definitely H2O and every... |
In the electrolysis of $\ce{Na2SO4}$, is it valid to write the anode half-reaction (oxidation) as
$$
\ce{OH-} \rightarrow \ce{H+} + \frac{1}{2}\ce{O2} + 2\ce{e-}
$$?
My book says it's
$$
\ce{H2O} \rightarrow 2\ce{H+} + \frac{1}{2}\ce{O2} + 2\ce{e-}.
$$
Other than the additional $\ce{H+}$, there's no differe... |
To understand the commonly quoted magnetic values of coordination complexes (central ion) we use
$$m_l=\sqrt{n(n+2)} \text{BM where BM}=\frac{e\hbar}{2m_e}\text{JT}^{-1}$$
$n$=number of unpaired electrons.
> ***How did we derive this equation?***
I know the orbital angular momentum of electron is given by... |
Charcoal (also [activated charcoal][1]) is known to adsorb a huge variety of substances including a variety of paints, dyes and many different kinds of ions. Moreover, the amount of [adsorption][2] at normal pressure and temperature is high. I know physisorption requires high capacity of Van-der-waal bonding with the a... |
The stoichiometric defects ([Schottky][1] and [Frenkel][2] defects) in ionic crystals are formed due to irregularities in ionic arrangement all the while maintaining the stoichiometry and electric neutrality. It is a fact that $\ce{AgBr}$ shows both Frenkel and Schottky defects while most other compounds show only one... |
The question is simple: What human-consumption safe liquid has the best caffeine solubility?
It's 200mg/10mL of water. That's a lot of water for one dose!
I found some ramblings on a fourm stating it's "low" solubility in propylene glycol and glycerine (glycol) but no sources or exact numbers, so that doesn't m... |
Best consumption-safe liquid for caffeine solubility? |
Why is it that sp3 hybridized carbonium ions do not exist? Or why are they very difficult to form?
For instance, nucleophilic substitution in bicyclo compounds at the bridge head carbon is not very easy. I don't understand the explanation given in the book. Thanks for any help. |
Why are carbocations with sp3 hybridisation highly unstable? |
I want to quantify a biotin-protein conjugate after chemical biotinylation. After biotinylation, the solution contains both biotinylated protein and free biotin.
I intend to use a HABA-avidin biotin quantitation kit like [this one][1] from Pierce. Since the biotinylated protein and the free biotin will both displace... |
How do I remove free biotin after biotin-protein conjugation? |
I am looking for references (review articles, reports) about non-stoichometric compounds. Any idea of where should I look?
|
If silicon dioxide tends to form a crystal lattice with four Os around a central S, why isn't the molecular formula SiO4 then? I'm confused why it's unique in that its molecular formula doesn't match up with its geometry.
I know it can be hard but please explain in a way a lowly gen chem 1 student like myself can un... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.