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Is an aqueous solution of calcium chloride hygroscopic? |
Below is a chemistry practice problem. I am curious why the change in heat of the oxygen molecules doesn't affect the calculations.
> Methylhydrazine ($\ce{CH6N2}$) is commonly used as a liquid rocket fuel. The combustion reaction is below. When 4.00 g of methylhydrazine is combusted in a calorimeter, the temperatu... |
Below is a chemistry practice problem. I am curious why the change in heat of the oxygen molecules doesn't affect the calculations.
> Methylhydrazine ($\ce{CH6N2}$) is commonly used as a liquid rocket fuel. The combustion reaction is below. When 4.00 g of methylhydrazine is combusted in a calorimeter, the temperatu... |
"Completely dry"? No, because molecules are always moving and there will be *some* exchange between desiccant and air. If you mean "below 10% relative humidity (RH)", there are a number of ways to do so:
* Consider that another way to discuss humidity is the [dew point][1]. Use a cold trap: after drying the air wit... |
It was written in my textbook,
$$
dU=\left(\frac{\partial U}{\partial T}\right)_VdT+\left(\frac{\partial U}{\partial V}\right)_TdV
$$
If the process is isothermal, $dT=0$. So, equation reduces to:
$$
dU=\left(\frac{\partial U}{\partial V}\right)_TdV
$$
I was told, $dU=0$ in isothermal process, does that m... |
In Isothermal process, how can the change in internal energy be 0? |
To put it simply, many books use the term 'Higher Oxide' or 'Lower Oxide'.
What does this mean? |
What is the meaning of an oxide being 'Higher' or 'Lower'? |
Why is CCl4 is seen to posses liquid state but CF4 gaseous state at room temperature? |
Why is [carbon tetrachloride $\ce{CCl4}$](https://en.wikipedia.org/wiki/Carbon_tetrachloride) is seen to posses liquid state (b.p. $\pu{76.72 °C}),$ whereas [carbon tetrafluoride $\ce{CF4}$](https://en.wikipedia.org/wiki/Tetrafluoromethane) is in gaseous state at room temperature (b.p. $\pu{−127.8 °C})?$ |
>>I was told, $dU=0$ in isothermal process.
That is *not* generally true. It is, however, true for ideal gases, which is probably what you were discussing. No attractive or repulsive forces exist between ideal gas particles. Hence the only type of internal energy an ideal gas can have is kinetic energy, i.e., e... |
Is it feasible to measure the pH of HF:H3COH:H2O solution using redox potential method?
Can I use this method to calculate the H+ ions in this solution and specifically, can I measure the changes in pH simultaneously as auto ionization is taking place? |
Is it feasible to measure the pH of HF:H3COH:H2O solution using redox potential method? |
Which compound should I avoid in deodorants to avoid "sticky, unwashable" feeling? |
Is it feasible to measure the pH of $\ce{HF}:\ce{H3COH}:\ce{H2O}$ solution using redox potential method?
Can I use this method to calculate the $\ce{H+}$ ions in this solution and specifically, can I measure the changes in pH simultaneously as auto ionization is taking place? |
Is it feasible to measure the pH of solution consisting of hydrofluoric acid, methanol and water using redox potential method? |
Why does the O atom of N-phenylnitrosamine donate its lone pair towards H+ when O is more electronegative than N? |
What is the role of hydration enthalpy in oxidation? |
Cl-CH2-CH2-CH2-I + KCN(1mole each) in acetone
I think the reaction should follow the second order nucleophilic substitution mechanism due to primar halide and strong nucleophile & iodine atom should be replaced giving Cl-CH2-CH2-CH2-CN as product but the book says the product is I-CH2-CH2-CH2-CN .Where am i wrong ? |
What should be the product of the following reaction? |
I am experimenting with different levels of concentrated caffeine solution. The Solution has a small percentage of Ethyl Alcohol, in the H2O.
Problems encountered too much Ethyl Alcohol solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows me adju... |
What formula allows adjusting balance of (Ethyl Alcohol / Water / Caffeine powder) to know concentration for the Caffeine solution? |
>What would be the product of the following reaction $\ce{Cl-CH2-CH2-CH2-I + KCN} $ ($\pu{1mol}$ each) in acetone?
I think the reaction should follow the second order nucleophilic substitution mechanism due to primary halide and strong nucleophile. Thus, iodine atom should be replaced giving $\ce{Cl-CH2-CH2-CH2-CN}... |
I am experimenting with different levels of concentrated caffeine solution. The Solution has a small percentage of Ethyl Alcohol, in the H2O.
Problems encountered too much Ethyl Alcohol solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows me adju... |
I am experimenting with different levels of concentrated caffeine solution. The Solution has a small percentage of Ethyl Alcohol, in the H2O.
Problems encountered too much Ethyl Alcohol solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows me adju... |
What is the difference between these two equations and when is appropriate to use which one?
We were told that F(J) in this case is
$F(J)= E/h$
And
$F(J) = BJ(J+1)$
$nu = 2B(J+1)$
(where nu is meant to signify wave number)
I have seen difference example problems use difference ones but it appe... |
What is the difference between these two equations and when is appropriate to use which one?
We were told that $F(J)$ in this case is
$F(J)= E/h$
And
$F(J) = BJ(J+1)$
$\nu = 2B(J+1)$
(where $\nu$ (nu) is meant to signify wave number)
I have seen difference example problems use difference ones bu... |
It was written in my textbook,
$$
\mathrm{d}U =
\left(\frac{\partial U}{\partial T}\right)_V \mathrm{d}T
+\left(\frac{\partial U}{\partial V}\right)_T \mathrm{d}V
$$
If the process is isothermal, $\mathrm{d}T = 0$. So, the equation reduces to:
$$
\mathrm{d}U = \left(\frac{\partial U}{\partial V}\right)... |
In an isothermal process, how can the change in internal energy be 0? |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
OK, now with more information I can maybe help a bit more...
>**47-mm diameter** Teflon membrane filters
This seems larger than a "typical" sample. I'd guess that your commercial instrument choices would be very limited by this sample size. (Note that you'd also want to spin the samples for greater uniformity...)... |
When undergoing copolymerization via free radical mechanism Buna-N forms a certain way.
[Actual product and possible products][1]
Can we predict which of the products will be formed based on the substituents?
If so, how?
[1]: https://ibb.co/NSq8gGS |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
I have performed a large number of calculations in order to determine the ethanol content of wine. These included titrations using burettes, mass measurements using analytical balances, and others. I know the uncertainties of the apparatus.
I am given a task to find the ethanol content of wine (done) but also to cal... |
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 solidifies the powder into clumps, adding water dissolves the clumps further into smaller clumps.
What formula allows ... |
The question "*Why does a hard-boiled egg have more entropy than a normal egg?*" was recently asked on one of my tests.
I said that entropy will decrease as a hard boiled egg has molecules in a more organised way than an raw egg, but I was marked wrong with a remark that entropy will increase because the proteins a... |
Why does a hard-boiled egg have more entropy than a normal egg? |
I want to produce Calcium Chloride container Desiccant for Food and Textiles related items.
I have this specs of Calcium Chloride and i have PP Non Woven Bags for its packaging. I want to know just to add this specs Calcium Chloride in bags to ... |
I want to produce calcium chloride container desiccant for food and textiles related items.
I have the below specs of calcium chloride and I have PP non woven bags for its packaging. I want to know whether I can just add the calcium chloride in bags to be used as desiccant? Or what other process is necessary?
... |
How to produce calcium chloride desiccant for ocean containers? |
> I was told, $\mathrm{d}U=0$ in isothermal process.
That is *not* generally true. It is, however, true for ideal gases, which is probably what you were discussing. No attractive or repulsive forces exist between ideal gas particles. Hence the only type of internal energy an ideal gas can have is kinetic energy... |
I've been reading Albright's Orbital Interactions in Chemistry. In the chapter on solids, he provided a general approach to find the band structure of a solid state system
[![enter image description here][1]][1]
Now if we are to model a one dimensional hydrogen chain, let $|1s(r)\rangle$ denote the $1s$ orbital... |
I've been reading Albright's Orbital Interactions in Chemistry. In the chapter on solids, he provided a general approach to find the band structure of a solid state system
[![enter image description here][1]][1]
[![enter image description here][2]][2]
Now if we are to model a one dimensional hydrogen chain, le... |
I've been reading Albright's Orbital Interactions in Chemistry. In the chapter on solids, he provided a general approach to find the band structure of a solid state system
[![enter image description here][1]][1]
[![enter image description here][2]][2]
Now if we are to model a one dimensional hydrogen chain, le... |
So I am writing a short paper on how one can produce Succinic acid from glycerol. I have to find a microorganism which can do that. I have found the following microorganism, which are traditionally being used for fermentation: Anaerobiospirillum succiniciproducens, Actinobacillus succinogenes, Mannheimia succiniciprodu... |
The NPR News podcast and transcript [The Convoluted Story Of How The First Atoms Of Tennessine Were Created](https://www.npr.org/2019/12/05/785253924/the-convoluted-story-of-how-the-first-atoms-of-tennessine-were-created) includes the following exchange between science reporter Joe Palca and Oak Ridge nuclear engineer ... |
Does tennessine end in -ine because it has 117 electrons? |
Does tennessine end in -ine because it has 117 electrons or because it behaves like a halogen? |
The NPR News podcast and transcript [The Convoluted Story Of How The First Atoms Of Tennessine Were Created](https://www.npr.org/2019/12/05/785253924/the-convoluted-story-of-how-the-first-atoms-of-tennessine-were-created) includes the following exchange between science reporter Joe Palca and Oak Ridge nuclear engineer ... |
The NPR News podcast and transcript [The Convoluted Story Of How The First Atoms Of Tennessine Were Created](https://www.npr.org/2019/12/05/785253924/the-convoluted-story-of-how-the-first-atoms-of-tennessine-were-created) includes the following exchange between science reporter Joe Palca and Oak Ridge nuclear engineer ... |
Is it tennessINE because it has 117 electrons or because it behaves like a halogen? |
I'm having trouble thinking through this problem. I know that when CO2 dissolves in water it can release HCO3- and H+ and cause a drop in pH. But can I use this to justify why CO2 (g) might dissolve more easily in a basic solution than an acidic one? Is the water acting as the base? |
Why is CO2 more likely to dissolve in a basic solution than an acidic solution? |
I'm having trouble thinking through this problem. I know that when $\ce{CO2}$ dissolves in water it can release $\ce{HCO3-}$ and $\ce{H+}$ and cause a drop in pH. But can I use this to justify why $\ce{CO2}$ (g) might dissolve more easily in a basic solution than an acidic one? Is the water acting as the base? |
So I am going to start a set of experiments involving the following metal nitrates-
1)Cobalt nitrate hexahydrate
2)Barium nitrate
3)cerium nitrate hexahydrate
4)ammonium nitrate nonahydrate
5)Iron(II) nitrate nonahydrate
All the products are from sigma Aldrich.
As I was going through the SDS data she... |
So I am going to start a set of experiments involving the following metal nitrates:
1. Cobalt nitrate hexahydrate
2. Barium nitrate
3. Cerium nitrate hexahydrate
4. Ammonium nitrate nonahydrate
5. Iron(II) nitrate nonahydrate
All the products are from Sigma-Aldrich.
As I was going through the SDS data sheets... |
Generally, personal protective equipment (PPE) is the last measure. First the employer has to check whether the risks to safety and health can be avoided (e.g. by replacing the toxic substances with substances that are not toxic). After that, the risks must be limited by technical means or collective protection or by m... |
everyone. I would like to test for the reaction between carbonic acid and copper (to simulate the effect of acid rain on copper). However, I find that many supplies failed to provide carbonic acid (either in powder or liquid form). Some says that carbonic acid is unstable and thus cannot supply it. Therefore, I want to... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
It exists only in minor concentration in water solutions of carbon dioxide and/or bicarbonates, with the equilibrium strongly shifted in favour of the oxide.
$$\ce{CO2 + H2O <<=> H2CO3}$$
----
Note that the acidity of [acid rain][2] is ... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
It exists only in minor concentration in water solutions of carbon dioxide and/or bicarbonates, with the equilibrium strongly shifted in favour of the oxide.
$$\ce{CO2 + H2O <<=> H2CO3}$$
----
Note that the acidity of [acid rain][2] is ... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
It exists only in minor concentration in water solutions of carbon dioxide ( soda water, mineral water ) and/or bicarbonates ( drink water, mineral water, baking soda solution ), with the equilibrium strongly shifted in favour of the oxide.... |
Crystalline PEO when under crossed polars shows distinct Maltese cross pattern. Being birefringent, when polymer crystal align with the polarizer or analyser it shows extinction regions (effect known as zero amplitude extinction). And as PEO crystallize in spherulites, it does lead to Maltese cross pattern. (As paralle... |
Why upon melting of PEO between crossed polars colours appear? |
I have to tell the name of the following compound
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/aZyY4.png
The name is **cyclopropyl-methyl-cyclobutane-carboxylate**. All of it makes sense but I don't understand why the suffix *carboxylate* comes? Why are we writing the single carb... |
I have to tell the name of the following compound
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/aZyY4.png
The name is **cyclopropylmethyl cyclobutanecarboxylate**. All of it makes sense but I don't understand why the suffix *carboxylate* comes? Why are we writing the single carbon... |
I read that "myristyl glucoside is a product obtained by the condensation of myristyl alcohol with aglucose polymer." Does that mean that alcohol is part of the final product/myristyl glucoside itself? Or is all of the alcohol removed during the making of it? |
Does myristyl glucoside contain alcohol? |
I was reading about the atomic orbital in my chemistry textbook. It says that the atomic orbital (psi) is a mathematical wave function that depends on the coordinates of the electron. It is also mentioned that psi does not carry any physical meaning. That part is understood, however I could not understand what a psi vs... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
It exists only in minor concentration in water solutions of carbon dioxide ( soda water, mineral water ) and/or bicarbonates ( drink water, mineral water, baking soda solution ), with the equilibrium strongly shifted in favour of the oxide.... |
I would like to test for the reaction between carbonic acid and copper (to simulate the effect of acid rain on copper). However, I find that many supplies failed to provide carbonic acid (either in powder or liquid form). Some says that carbonic acid is unstable and thus cannot supply it. Therefore, I want to make it m... |
Easy way to make carbonic acid from other chemicals? |
This is the equation given by my textbook for Hydrolysis of Sodium carbonate :
>$Na_2CO_3 + 2H_2O ⇢ H_2CO_3 + 2Na^{+} + 2OH^{-}$
and it mentions that Sodium ion($Na^{+}$) does not tend to combine with the Hydroxide ion($OH^{-}$) and i was wondering what prevents them from combining together to form $NaOH$ ?
t... |
I want to determine the iodine value of a fatty oil. For this I dissolve 1.0 g of the oil in chloroform. Iodine bromide is then added and placed in a dark room for at least 30 minutes. After this, KI is added. Then, I am going to to titrate with 0.1 M Na2SO3. Based on the added volume, I can calculate the iodine value ... |
To calculate the amount of purified water and the amount of ethanol (96% Vol.) which is needed for a **desired/variable amount of their mixture** - given a desired/variable percentage of ethanol - I use the following formula:
$$W = \left(\frac{T * P}{ 100}\right) \times \frac{1}{0,96}$$
and
$$E = T - W$$
... |
>I want to determine the iodine value of a fatty oil. For this I dissolve $\ce{1.0 g}$ of the oil in chloroform. Iodine bromide is then added and placed in a dark room for at least $\pu{30 min}$. After this, $\ce{KI}$ is added. Then, I am going to titrate with $\pu{0.1 M}$ $\ce{Na2SO3}$. Based on the added volume, I ca... |
Determination of the iodine value of a fatty oil: Does the concentration of Na2SO3 effect the iodine value? |
To calculate the amount of purified water and the amount of ethanol (96% Vol.) which is needed for a **desired/variable amount of their mixture** - given a desired/variable percentage of ethanol - I use the following formula:
$$W = \left(\frac{T * P}{ 100}\right) \times \frac{1}{0,96}$$
and
$$E = T - W$$
... |
Why don't molecular orbitals change when electrons are added or removed from a molecule? |
To calculate the amount of purified water and the amount of ethanol (96% Vol.) which is needed for a **desired/variable amount of a mixture** - given a desired/variable percentage of ethanol - I use the following formula:
$$W = \left(\frac{T * P}{ 100}\right) \times \frac{1}{0,96}$$
and
$$E = T - W$$
... |
To calculate the amount of purified water and the amount of ethanol (96% Vol.) which is needed for a **desired/variable amount of a mixture** - given a desired/variable percentage of ethanol - I use the following formula:
$$W = \left(\frac{T * P}{ 100}\right) \times \frac{1}{0,96}$$
and
$$E = T - W$$
... |
> Molarity of diluted $\ce {H2SO4}$ (solution 2): $\pu{0.0013798 mol}/\pu{0.025 L} = \pu{0.054172 M}$
(I may be using the wrong volume, is it possible that I have to add the $\pu{25 ml}$ to the $\pu{23.81 ml}$ and divide by $\pu{0.04881 L}$?)
No, you used the correct volume since you want to know the concentratio... |
In my latest chem lab the objective was to create a primary standard of $\ce{NaOH}$ and use it to determine the concentration of sulfuric acid.
The **first part** of the lab was determine the molarity of the $\ce{NaOH}$ solution through a series of titrations.
- A sample of KHP (abbreviated form of $\ce{KHC8H4O... |
In organic chemistry lecture, we were given a chart of approximate signal shift ranges for different carbon types in CNMR spectra. carbonyl carbons (C=O) have a range of about 155-210 ppm, but the nitrile group (C≡N) has a signal range of about 110-140 ppm. I understand that oxygen is a more electronegative atom, so it... |
Why does the nitrile carbon experience more shielding than a carbonyl carbon in CNMR? |
To calculate the amount of purified water and the amount of ethanol (96% Vol.) which is needed for a **desired/variable amount of a mixture** - given a desired/variable percentage of ethanol - I use the following formula:
$$W = \left(\frac{T * P}{ 100}\right) \times \frac{1}{0.96}$$
and
$$E = T - W$$
... |
How to produce produce gel for ocean? |
In my lab experiment for the synthesis of Aspirin we used hot water to quench the reaction. Why wouldn't we use cold water but hot water? |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
In a pure form, it exists only as its salts: bicarbonates ( of alkali metals ) and carbonates.
As an acid, it exists only in minor concentration in water solutions of carbon dioxide ( soda water, mineral water ) and/or bicarbonates ( drink ... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**
In a pure form, it exists only as its salts: bicarbonates ( of alkali metals ) and carbonates.
As an acid, it exists only in minor concentration in water solutions of carbon dioxide ( soda water, mineral water ) and/or bicarbonates ( drink ... |
What is the difference between these two equations and when is appropriate to use which one?
We were told that $F(J)$ in this case is
$F(J)= E/h$ for units in frequency
And
$F(J) = BJ(J+1)$
$\nu = 2B(J+1)$
(where $\nu$ (nu) is meant to signify wave number)
I have seen difference example problems... |
As a kid I never imagined equilibrium to be a state where both forward and backward reactions keep taking place. Although, by seeing one cannot tell. Why is it that both forward and backward reactions move at a constant rate once equilibrium is achieved(dynamic, of course).
For instance, why at 273K ice molecules t... |
Why does a reaction move both forward and backward in dynamic equilibrium? |
Why ? Because nature of matter at molecular and atomic level is dynamic, not static. In classical mechanics, objects can be in long term mutual rest. Not in quantum mechanics and quantum chemistry.
The dynamic bidirectional state of the dynamic equilibrium applies not only to chemistry, but to all the thermodynamics a... |
You have to evaluate shortcomings as compared to something. You can make a list and say "but InChI doesn't represent X" where X is ranging around
- Markush groups
- polymers from repeat units
- reactions
- toasters
The point is: so what? All representations have some limitations. But limitations aren't sh... |
**[Carbonic acid][1] does not exist either in powder either in liquid form.**. ( It can be created and detected at special conditions and not in macroscopic amounts, as noted in the link.)
In a pure form, it exists only as its salts: bicarbonates ( of alkali metals ) and carbonates.
As an acid, it exists only in mino... |
You have to evaluate shortcomings as compared to something. You can make a list and say "but InChI doesn't represent X" where X is ranging around
- mixtures
- Markush groups
- polymers from repeat units
- reactions
- toasters
The point is: so what? All representations have some limitations. But limitati... |
**[Carbonic acid][1] does not exist either in powder either in liquid form near normal conditions.**. ( It can be created and detected at special kryogenic or gaseous phase conditions not applicable for its usage as "on shelf acid".)
In a pure form, it exists only as its salts: bicarbonates ( of alkali metals ) and c... |
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