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I bake bread using a sourdough starter. The starter is a culture of lactobacillus and some kind of yeast. They apparently eat the sugars or carbohydrates in the dough during fermentation but when I look at the nutritional info for fully baked sourdough bread I see 56gm of carbohydrates per 100gm and my question is, why... |
In sourdough bread baking what do the wild yeast and bacteria not eat during dough fermentation and why? |
Glycinate as far as I can guess from the structure is a monoanion with negative charge on oxygen atom (though that negative charge is resonating). But when I used this logic in my exam it costed me 4 marks. I don't understand why.
Is it because it is derived from glycine in strongly basic medium which is not a monoa... |
Is glycinate ligand a monoanion or a zwitterion? |
From the introduction in a [paper][1] on the different lactic acid bacteria (LAB) cultures in sourdough:
>Sourdough LAB give rise to the characteristic qualities of several kinds of foods (flavor, texture, taste, and shelf life) by producing metabolites such as lactic acid, acetic acid, and ethanol. However, it is n... |
From the introduction in a [paper][1] on the different lactic acid bacteria (LAB) cultures in sourdough:
>Sourdough LAB give rise to the characteristic qualities of several kinds of foods (flavor, texture, taste, and shelf life) by producing metabolites such as lactic acid, acetic acid, and ethanol. However, it is n... |
From the introduction in a [paper][1] on the different lactic acid bacteria (LAB) cultures in sourdough:
>Sourdough LAB give rise to the characteristic qualities of several kinds of foods (flavor, texture, taste, and shelf life) by producing metabolites such as lactic acid, acetic acid, and ethanol. However, it is n... |
In a mixture of AgCl (s) and initial 0.10 M KI, what is the [I-] after the reaction proceeds?
Disclaimer: This is not a graded assignment, but rather a problem I'm trying to figure out for practice purposes from my textbook.
|
Recently we learnt that there is a depression in freezing point when a non volatile solute is added to the solvent. Our teacher explained this phenomenon with a graph where the vapor pressure of the solution and pure solvent intersects with the vapor pressure of solid solvent. my question is: wouldnt the vapour pressur... |
I am having a hard time understanding what happens at equilibrium in an electrochemical cell (a full cell with two electrodes). At equilibrium, according to Nernst equation, the cell potential is $E_{cell}=E^0_{cell}-\frac{RT}{zF}lnQ_r$. Is this cell potential equal to the voltage of the cell ? At equilibrium, the volt... |
What is the voltage of an electrochemical cell at equilibrium? |
I came across this reaction where simple electrophilic addition mechanism will result in a vic-di iodide.[![enter image description here][1]][1]
But when i checked the solution it says that vicinal iodine groups are unstable and the following reaction occurs.[![enter image description here][2]][2]
[1]: http... |
Why is vicinal di iodine compound unstable, leading to deiodonation? |
Yesterday I blued my new carbon steel wok over a very high (200K BTU) burner which is capable of getting the wok to 1000+ degrees with ease.
I understand that bluing adds a rust-resistant layer which is triggered by a chemical reaction at around around [575 F](https://i.stack.imgur.com/h930a.png).
In this case I ... |
Does the anti-rust properties of bluing carbon steel disappear at a certain temperature? |
I came across this reaction where simple electrophilic addition mechanism will result in a vic-di iodide.
$$\ce{H2C=CH-CH2-I ->[HI(excess)][CCl4]}$$
But when i checked the solution it says that vicinal iodine groups are unstable and the following reaction occurs.
$$\ce{CH3-\underset{(unstable)}{\underset{\unde... |
Why is vicinal-di-iodopropane unstable, leading to deiodonation? |
A question in my book asks:
*In the reaction:*
[![enter image description here][1]][1]
*The intermediate(s) is/are*?
The correct answers are given as
[![enter image description here][2]][2]
However, as per my knowledge, compound (b) does not appear in the reaction mechanism. Is this an error in ... |
**This arises as a sub-question for the following question:** Calculate the concentration of I- in a solution obtained by shaking 0.10 M KI with an excess of AgCl(s).
*I tried to look at https://chemistry.stackexchange.com/q/147910/105739, but it didn't answer my question which I detailed below.*
**My textbook s... |
Why is the Ag+ concentration in a beaker fixed in the reaction between excess AgCl (s) and KI (aq) from the start? |
In a mixture of $\ce{AgCl(s)}$ and initial $\pu{0.10 M}$ $\ce{KI}$, what is the $[\ce{I-}]$ after the reaction proceeds?
Disclaimer: This is not a graded assignment, but rather a problem I'm trying to figure out for practice purposes from my textbook.
|
So I was comparing the $+M$ effect of $\ce{CH^-_2}$, $\ce{NH^-_2}$ and $\ce{O^-}$. Answer was given as:
$$ \ce{CH^-2 > NH^-_2 > O^-}$$
So, I attach them with ethene and made their respective resonating structures as:
$\require{enclose}$
1. $\ce{\underset{(a)}{CH2=CH-\overset{\enclose{circle}{-}}{CH2}} <-> \un... |
So I was comparing the $+M$ effect of $\ce{-CH^-_2}$, $\ce{-NH^-}$ and $\ce{-O^-}$. Answer was given as:
$$ \ce{-CH^-2 > -NH^- > -O^-}$$
So, I attach them with ethene and made their respective resonating structures as:
$\require{enclose}$
1. $\ce{\underset{(a)}{CH2=CH-\overset{\enclose{circle}{-}}{CH2}} <-> \... |
So I was comparing the $+M$ effect of $\ce{-CH^-_2}$, $\ce{-NH^-}$ and $\ce{-O^-}$. Answer was given as:
$$ \ce{-CH^-2 > -NH^- > -O^-}$$
So, I attach them with ethene and made their respective resonating structures as:
$\require{enclose}$
1. $\ce{\underset{(a)}{CH2=CH-\overset{\ominus}{C}H2} <-> \underset{(b)... |
I have read a teensy bit of the subject matter and the explanation they provided for silver iodide's ability to being a good site for ice to form is because of its size resembling an ice nucleus.
How exactly does silver iodide adsorb water onto its surface? is it hygroscopic?
Ice crystals growing larger due to vapo... |
Are compounds which are used to seed clouds like (AgI) hygroscopic? |
I have read a teensy bit of the subject matter and the explanation they provided for silver iodide's ability to being a good site for ice to form is because of its size resembling an ice nucleus.
How exactly does silver iodide adsorb water onto its surface? Is it hygroscopic?
Ice crystals growing larger due to vapo... |
Are compounds which are used to seed clouds like silver(I) iodide hygroscopic? |
**This arises as a sub-question for the following question:** Calculate the concentration of I- in a solution obtained by mixing 0.10 M KI with an excess of AgCl(s).
*I tried to look at https://chemistry.stackexchange.com/q/147910/105739, but it didn't answer my question which I detailed below.*
**My textbook sa... |
I was very confused by this problem. I was able to get the molarity, but I wasn’t certain how to go from there:
If 2.60 g of NaBr is dissolved in enough water to make 160. mL of solution, what is the molar concentration of NaBr? How many milliliters of 0.10 M NaBr would you need to supply 2.60 g of NaBr?
Molarity = 0... |
I was very confused by this problem. I was able to get the molarity, but I wasn’t certain how to go from there:
If $\pu{2.60 g}$ of $\ce{NaBr}$ is dissolved in enough water to make $\pu{160.0 mL}$ of solution, what is the molar concentration of $\ce{NaBr}$? How many milliliters of $\pu{0.10 M}$ $\ce{NaBr}$ would you... |
This happens because higher number of fluorine atoms induce a higher positive oxidation state on Xe which causes the Xe atom to shrink in size resulting in a smaller bond length.
XeF2 has Xe in +2 oxidation state while XeF6 has it in +6 oxidation state
[link](https://edu.rsc.org/download?ac=135029) |
Anyone with experience making sodium metal (Na) with the following process? Reactants: 14 g magnesium powder, 20 g sodium hydroxide; Catalysts: 1 to 2 g Menthol Crystals; Reagent: 125 mL Mineral Oil with no additives. Can use 3 to 4 g sodium metal to remove any H2O in the NaOH during the first two hours of stirring at ... |
I decided to give a help here since OP has given enough effort to solve this problem. First, OP needs to know the molarity of a solution is defined as the amount of solute (in this case $\ce{NaBr}$) in $\pu{mol}$ per $\pu{1.0 L}$ of solution. The first part of problem states:
>If $\pu{2.60 g}$ of $\ce{NaBr}$ is diss... |
I decided to give a help here since OP has given enough effort to solve this problem. First, OP needs to know the molarity of a solution is defined as the amount of solute (in this case $\ce{NaBr}$) in $\pu{mol}$ per $\pu{1.0 L}$ of solution. The first part of problem states:
>If $\pu{2.60 g}$ of $\ce{NaBr}$ is diss... |
I decided to give a help here since OP has given enough effort to solve this problem. First, OP needs to know the molarity of a solution is defined as the amount of solute (in this case $\ce{NaBr}$) in $\pu{mol}$ per $\pu{1.0 L}$ of solution. The first part of problem states:
>If $\pu{2.60 g}$ of $\ce{NaBr}$ is diss... |
Anyone with experience making sodium metal ($\ce{Na}$) with the following process? Reactants: $\pu{14 g}$ magnesium powder, $\pu{20 g}$ sodium hydroxide; Catalysts: $1$ to $\pu{2 g}$ menthol crystals; Reagent: $\pu{125 mL}$ mineral oil with no additives. Can use $3$ to $\pu{4 g}$ sodium metal to remove any $\ce{H2O}$ i... |
I want to draw arrows like the one in the figure shown (with reagent *a* beside it) in ChemDraw 16.0[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/Qp2jP.png
What is the best way to go about this?
I couldn't find anything like it in the arrow options in ChemDraw Prime 16.0
|
> please teach how to use gaussian or lorentzian function.
It will take several hours of discussion or 4-5 lectures. You are mixing several things.
a) Briefly, your collected spectrum is noisy. You want to remove the noise. What type of spectra is this?
b) The finite resolution of your spectrometer has nothin... |
Lattice energy decreases down the group but stability of the compound still increases why?
For the purpose of this post I'll take alkali earth metal carbonate as an example.
As we go down the group size of cation increases and hence the lattice energy decreases, however my book stated that
> The thermal stability... |
I'm writing something where the characters are looking for someone among a large set of people. They don't know who this person is and they don't know what they're looking for, so their best bet is to look for anything unusual about this person. I already have a method by using which they'll eventually find him, but I ... |
I understood that stability of Enols are dependent on the hydrogen bonding in the compounds. But here, what is the significance of **more than one percent enol content?**
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/qlgGi.jpg |
Which of the following compounds possess more than one percent enol content? |
What yeast does:
glucose => etanol + carbon dioxide.
What lactobacilus does:
glucose => lactic acid
They usually don't find glucose around them, so they first break down starch first (starch is abundant in the dough).
They both also do other things, like making new cells from the ingredients they find ar... |
My textbook Chemistry Part 1,as in the attached photo states that[after the KClO3 reaction]
“This reaction which apparently seems to be of the tenth order is actually a second order reaction. This shows that it takes place in several steps.” If that is so, then as stated above it, all higher order inorganic chemistry ... |
Why Inorganic chemistry reaction mechanisms are hard to find? |
What yeast does:
glucose => etanol + carbon dioxide.
What lactobacilus does:
glucose => lactic acid
They usually don't find glucose around them, so they break down the starch first (starch is abundant in the dough).
They both also do other things, like making new cells from the ingredients they find arou... |
Good candidates for your research would be the fallout residues of atomic bombs having exploded in the world between $1945$ and $1964$. These bombs were made by USA and the former USSR (Russia today) during the "cold war". Each time one of these superpowers had developed a "more powerful" bomb, the other one managed to... |
I was looking at the description of the tetragonal group $$P 4_{2} 2 2$$ (No 93 in the International Tables of Crystallography) and there is one aspect that I do not understand. Namely, what is the convention and implications of choosing the origin point? For example, for the two fold rotation along the [110] plane, th... |
I was looking at the description of the tetragonal group $$P 4_{2} 2 2$$ (No 93 in the International Tables of Crystallography) and there is one aspect that I do not understand. Namely, what is the convention and implications of choosing the origin point? For example, for the two fold rotation along the [110] plane, th... |
As a side reaction of Grignard reagents, the following reaction is introduced on the Internet.
I think this is β-hydride elimination reaction, but magnesium is a main group metal, not a transition metal.
Does β-hydride elimination reaction in main group metals occur?
[![enter image description here][1]][1]
[1]: ht... |
Does β-hydride elimination in main group metals occur? |
> Which of the following compounds possess more than one percent enol content?
>
> [![enter image description here][1]][1]
I understood that stability of enols are dependent on the hydrogen bonding in the compounds. But here, what is the significance of *more than one percent enol content*?
[1]: https://i.s... |
> Can a spark ignite hydrogen? Also, what about the tip of a cigarette?
Yes, if the $\ce{H2(g)}$ concentration in oxygen or air is greater than about 4% not only will it burn, but most likely explode. You should avoid all heat sources when dealing with it, including direct sunlight. Just so you know, hydrogen safety... |
I'd like to do a DNA quantification experiment for a college project, for obvious reasons I don't want to use 16M sulfuric acid. Is it possible to use more dilute acid and get a reasonably good result? Sorry if this is a bad question. |
Do you need *concentrated* sulfuric acid to make Dische diphenylamine reagent and test for DNA? |
I'd like to do a DNA quantification experiment for a college project. I don't want to use 16 M sulfuric acid. Is it possible to use more dilute acid and get a reasonably good result? |
Do you need concentrated sulfuric acid to make Dische diphenylamine reagent and test for DNA? |
I am not sure to understand something I read in a educational journal (1)
# introduction
Lets consider the following reversible enzyme-catalysed reversible reaction;
> $E + S \leftrightharpoons ES \leftrightharpoons E + P$
with forward rate constants $k_1$ and $k_2$ and backward rate constants $k_{-1}$ and ... |
How do enzymes affect a reaction's equilibrium? |
I am not sure to understand something I read in a educational journal (1)
# Introduction
Lets consider the following reversible enzyme-catalysed reversible reaction;
> $E + S \leftrightharpoons ES \leftrightharpoons E + P$
with forward rate constants $k_1$ and $k_2$ and backward rate constants $k_{-1}$ and ... |
Is there a reason for why most medicines are in salt form?
Why not have them in conjugate base form? |
Why are most medicines in salt form? |
Good candidates for your research would be the fallout residues of atomic bombs having exploded in the world between $1945$ and $1964$. These bombs were made by USA and the former USSR (Russia today) during the "cold war". Each time one of these superpowers had developed a "more powerful" bomb, the other one managed to... |
(Please forgive me for asking this if it's obvious, but it's not obvious to me.)
Does sodium bicarbonate permanently denature vitamin C in such a way that vitamin no longer has health-giving antioxidant properties? [This question][1] seems to say sodium bicarbonate does not harm vitamin C's nutritional properties. A... |
Does sodium bicarbonate permanently denature vitamin C? |
Does sodium bicarbonate permanently eliminate health-giving properties of vitamin C? |
(Please forgive me for asking this if it's obvious, but it's not obvious to me.)
Does sodium bicarbonate permanently eliminate vitamin C's health-giving properties? [This question][1] seems to say sodium bicarbonate does not harm vitamin C's nutritional properties. Am I correct?
[1]: https://chemistry.stackex... |
(Please forgive me for asking this if it's obvious, but it's not obvious to me.)
Does sodium bicarbonate permanently eliminate vitamin C's nutritional properties? [This question][1] seems to say sodium bicarbonate does not. Am I correct? I am easily confused by chemistry, so please give me a very simple answer, foll... |
Does sodium bicarbonate permanently eliminate nutritional properties of vitamin C? |
[![enter image description here][1]][1]
[1]: https://i.stack.imgur.com/CiI0R.png
I was in the middle of my acid and base schools questions when I came to a stop at this question. I have posted the answer to tell you what I am confused about. My teacher did not explain this very well, and my friends are not sure... |
What happened to the Na+ ion? |
We learn in my chemistry course that there must be a snug fit for a host-guest complex to form.
So, something like benzene (0.6nm in diameter) can form a host-guest complex with a beta-cyclodextrin host (0.7nm cavity).
Other than this vaguely-worded 'snug-fit' rule, we're not given a lot of information of what molecu... |
In my book it's said that there are 3 types of unit cubic cell - primitive , face and body centered . But for 3d packing types they have only mentioned FCC and HCP . I know that these 2 concepts- unit cell and packing types are different but it's the packing that determines the type of unit cell , right ? So are there... |
How many types of 3D packing are possible? |
Why are magnesium ascorbate and potassium acetate, which are salts of strong bases with weak acids, acidic?
I discovered with litmus paper that magnesium ascorbate is acidic and found out from https://foodb.ca/compounds/FDB015417 that potassium acetate should also be acidic.
How can this be? Shouldn’t conjugate b... |
Why is vicinal-di-iodopropane unstable, leading to deiodination? |
I need to find the velocity at which the fraction is maximum in Maxwell–Boltzmann distribution
$$P(v) = \left(\frac{m}{2\pi kT}\right)^{3/2}4\pi v^2 \exp{\left(-\frac{mv^2}{2kT}\right)}$$
I know that occurs when $\mathrm dP(v)/\mathrm dv = 0$, but can anyone show the steps which leads to the answer? |
I need to find the velocity at which the fraction is maximum in Maxwell–Boltzmann distribution
$$P(v) = \left(\frac{m}{2\pi kT}\right)^{\frac{3}{2}}4\pi v^2 \exp{\left(-\frac{mv^2}{2kT}\right)}$$
I know that occurs when $\mathrm dP(v)/\mathrm dv = 0$, but can anyone show the steps which lead to the answer? |
We learn in my chemistry course that there must be a snug fit for a host-guest complex to form. So, something like benzene ($\pu{0.6 nm}$ in diameter) can form a host-guest complex with a $\beta$-cyclodextrin host ($\pu{0.7 nm}$ cavity).
Other than this vaguely-worded 'snug-fit' rule, we're not given a lot of informat... |
We learn in my chemistry course that there must be a snug fit for a host-guest complex to form. So, something like benzene (0.6 nm in diameter) can form a host-guest complex with a β-cyclodextrin host (0.7 nm cavity).
Other than this vaguely-worded ‘snug-fit’ rule, we are not given a lot of information of what molecul... |
What are the limits of size differences in a host–guest complex? |
(Please forgive me for asking this if it's obvious, but it's not obvious to me.)
**EDIT: I am easily confused by chemistry, so please give me a very simple answer, followed by any lengthy further explanation (if you feel it's needed.) Please pretend you are speaking to a 5 year old. Thank you in advance.**
Does b... |
Does baking soda permanently eliminate nutritional properties of vitamin C? |
This is the problem:
[![enter image description here][1]][1]
Calculate the Ecell (not E°) at 25°C.
I added the E°Cu2+/Cu and E°Fe2+/Fe to get E°cell = -.101. But I'm not even sure if I'm supposed to add them or subtract them because I've seen both done, which is really confusing me. In what situations do you ... |
This is the problem:
[![enter image description here][1]][1]
Calculate the Ecell (not E°) at 25°C.
I found that the reaction is Cu(s) + Fe2+(aq) ➜ Cu2+(aq) + Fe(s). Cu gets oxidized and Fe2+ gets reduced.
I added the E°Cu2+/Cu and E°Fe2+/Fe to get E°cell = -.101. But I'm not even sure if I'm supposed to ad... |
This is the problem:
[![enter image description here][1]][1]
Calculate the Ecell (not E°) at 25°C.
I found that the reaction is Cu(s) + Fe2+(aq) ➜ Cu2+(aq) + Fe(s). Cu gets oxidized and Fe2+ gets reduced.
I added the E°Cu2+/Cu and E°Fe2+/Fe to get E°cell = -.101. But I'm not even sure if I'm supposed to ad... |
I am doing an online assignment where I am being asked to find temperature change but there is something wrong in my calculations as I am getting the answer wrong. Can someone help me figure out where I went wrong in my calculations?
**Assignment Instructions:**
Solve for the unknown variable using the specific h... |
What did I do wrong in my temperature change calculations? |
I just have a quick question about partial derivatives/mathematical relations in thermodynamics. Is the following statement correct?
$$\frac{\partial }{\partial v}\left [ \left ( \frac{\partial p}{\partial T} \right )_{v} \right ]_{T}=\left ( \frac{\partial ^2p}{\partial v\partial T} \right )_{v,T}$$ |
Is this shorthand notation correct for the partial derivatives in thermodynamics? |
Say I have a gas cylinder with nitrous oxide and cool it down to -78 °C with dry ice. Is there an endothermic process/reaction that would extract the remaining heat from N2O and bring it down by 10 °C to its boiling point of -88 °C? I know this could be done by using cryogenics like liquid nitrogen but I want to avoid ... |
This is the problem:
[![enter image description here][1]][1]
Calculate the ${E_\mathrm{cell}}$ (not ${E°}$) at 25°C.
I found that the reaction is $$\ce{Cu(s) + Fe^2+(aq) -> Cu^2+(aq) + Fe(s)}$$ $\ce{Cu}$ gets oxidized and $\ce{Fe^2+}$ gets reduced.
I added the ${E°_\mathrm {Cu^{2+}/Cu}}$ and ${E°_\mathrm{F... |
I've been told by my teacher that van der waals forces is the formal name for intermolecular forces. But on the internet, many people are saying van der waals forces is another name for London dispersion forces. If van der waals forces is another name for dispersion forces, why is it named after another scientist? |
Which definition of van der waals forces is correct? |
In a problem, it was stated that at 25 degrees Celsius, the K(eq)<1. The question than asked whether T(Δ(S)) was larger than, smaller than, or equal to ΔH for this reaction and the equation ΔG = ΔH - TΔS. Given that the reaction is at equilibrium, I assumed that TΔS had to equal ΔH, since ΔG would equal 0 at equilibriu... |
I've been told by my teacher that van der Waals forces is the formal name for intermolecular forces. But on the internet, many people are saying van der Waals forces is another name for London dispersion forces. If van der Waals forces is another name for dispersion forces, why is it named after another scientist? |
Which definition of van der Waals forces is correct? |
This has gotten me confused since long. Not all equations have clean half- reactions, some cations are in more than one compound while some anions are in some other compounds. Some reactions don't even have any charges and just look like normal equations (if you dont seperate ions), should we just balance them like nor... |
I recently came across this question, which required me to know the difference between performing a Birch reduction on naphthalene using ethanol and using isopentanol. Why does using isopentanol lead to that extra hydrogenation?
[![Reactions of naphthalene][1]][1]
[1]: https://i.stack.imgur.com/7NQkq.jpg |
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