# All Questions

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### Purity of aluminium and experimental setup differences between Hoope and Hall–Héroult processes

Recently I was taught how aluminium is commercially extracted. The ore is first concentrated by leaching either by Bayer's process for red bauxite (impurity: $\ce{Fe2O3}$) or by Serpeck's process for ...
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### Can triethylene glycol be used to remove polypropylene from the die during the glycol bath process?

We use the glycol bath die cleaning process in order to clean our die which are used to extrude materials from PBT and PET. Can triethylene glycol be used in order to clean a die containing ...
10 views

### how to test for purity

Is there a home testing method for the purity of lgd4033? Formula: C14H12F6N2O IUPAC ID: 4-((R)-2-((R)-2,2,2-trifluoro-1-hydroxyethyl)pyrrolidin-1-yl)-2-trifluoroMethyl)benzonitrile Elimination half-...
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### Which is more stable , a phenyl carbanion or a ethyl carbanion?

I came across this question in my class test and the answer given is ethyl carbanion . But as per the S character and electronegativity , the phenyl carbanion should be more stable . My teacher told ...
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### Why does snow sublime even when the surrounding temperature is below 0 °C?

Snow in winter below 0 °C, still sublimed very slowly over time. If I’m not mistaken, sublimation is an endothermic process. Where is this absorbed energy coming from when the surrounding temperature ...
14 views

### Enthalpy Changes [on hold]

0.50 g of Mg is added to a 50 mL HCl solution. The temperature increased by 5.2 degree Celsius. Calculate the enthalpy change for the reaction per mole of Mg that reacted.
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### Which of the following are identical?

So what i know is that when we rotate a fisher projection by 180° then we get identical compounds Going with that i think the option 1 should be correct but in the key the option 4 is given as ...
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### If water freezes at 32 °F (0 °C) at sea level, then what temperature does ice melt?

If water freezes at 32 °F, what happens to that newly formed ice at that temperature? Does it start melting as soon as it’s frozen, or does it require more heat to melt again? If it does require more ...
17 views

### How is Zn not a transition metal?

A transition metal can be defined as an element that possesses an incomplete sub-level in one or more of its oxidization states. In the textbook I'm reading, it claims that zinc is not a transition ...
13 views

### Salt recovery from brine solution

I have a solution of brine (NaCL) which after passing in to multiple effect evaporator its become saturated and some crystalline. We pass that solution in the centrifuge to recover salt but the ML ( ...
11 views

### How can i change atom color or size partially in VMD 1.9.3? [on hold]

For examples, I want that some carbons are changed to red while the other carbons are changed to blue. I don't want that changing all carbon to other color or size. Please explain to me in details.
20 views

### Synthesize of N-(heptane-4-yl)-N-phenylpropionohydrazide [on hold]

I have the following question I tried to answer and I couldn't and I searched the internet and I couldn't. I appreciate any help
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### calculations buffer solution using pka and henderson's equations [on hold]

What is the $\mathrm{pH}$ of mixture of $\pu{5ml}$ of $\pu{0.1M}$ of $\ce{CH3COONa}$ and $\pu{4 ml}$ of $\pu{0.1M}\ce{ CH3COOH}$.If the $\mathrm{p}K_\mathrm{a}$ is 4.76? How is the $\mathrm{pH}$ ...
174 views

### Which biphenyl is optically active?

Which biphenyl is optically active? I know that it can never be 1. I don't think it will be 4 either as I read that it should be ortho-substituted biphenyl. So, when I look at 2 and 3, I can't ...
31 views

### What software packages can be used to computationally model electrochemical reactions? [on hold]

I'm looking for software, other than COMSOL Multiphysics, which models electrochemistry (particularly electrocatalysis) effectively. Any suggestions would be very useful. I already have access to ...
19 views

### Furniture spray recipe [on hold]

I am trying to formulate a natural furniture spray with a small amount of beeswax, olive (or mineral) oil, and polysorbate 80 and water. In order to emulsify the oils enough to spray, a large amount ...
10 views

### is Mg(OH)2 able to remove the free PO4 3- ions produced by the hydrolysis of phenolphthalein phosphate using phosphatase

I wanted to investigate the effects of magnesium ions on preventing the end production inhibition of phosphate ions on phosphatase enzymes (from splitting phenolphthalein phosphate, PPP). My idea was ...
19 views

### Ka for reaction from tables [duplicate]

For the reaction below: NH4+ + H2O -> NH3 + H30+ I have the following values from a table to use: And in the solution manual they tell me to use the Ka for this reaction. Why is this? Why do we ...
28 views

### Phenolphthalein and methyl orange end points comparison

In determining the solubility constant for Ca(OH)2, how does phenolphthalein end point compare with the methyl orange end points?
16 views

### Ph2C=CH2 (1), PhCH=CHPh(2) , PhCH=CHCH3(3) reactivity order towards HCL [on hold]

Ph is phenyl group and according to me it is 1>2>3
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### Which is more reactive towards Grignard reagent, RCOOR or RCONH2? [on hold]

My answer is RCONH2 BUT IT IS GIVEN RCOOR WHY
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### Which plasticizers can be used in resole urea formaldehyde resin in making decorative laminates? [on hold]

I am looking for a non-glycol group, superior than Diethylene glycol.
24 views

### What apparatus is needed to get a balloon full of anhydrous carbon dioxide from solid carbon dioxide? [on hold]

I'm currently planning a research project (new to this) and we need to bubble CO2 through our reaction mixture, however we are not able to use compressed gas so have been advised to pass CO2 from dry ...
31 views

### Heat capacity calculation with temperature dependence [on hold]

I understand that when the heat capacity depends on temperature you can perform an integration. For the equation $C_p = a + bT + c T^2$: In order to compute change of entropy we have to integrate ...
26 views

I want to do a PES scan of a radical structure in Gaussian. However, I'm not completely sure how to prepare an input file. I've figured out that charge and multiplicity are 0 and 2. What I don't know ...
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57 views

### Oxidation States of D Block Elements

These might be basic question but they are quite confusing to me? If $\ce{Sc+}$ doesn't exists, why does $\ce{Ti^{2+}}$ exist? on the similar account why does this trend increases at first( till Mn)...
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44 views

### Entropy as an intrinsic property of matter

I would like to ask how we can see entropy as an intrinsic property of molecules, namely as something depending also on their geometry (and not only as gross disorder). Is this what is called the "...
19 views

### Copper plating with switched anode and cathode [on hold]

Please help! I was working on a mock research project/lab for my chemistry class testing the rate of electroplating of copper vs. voltage. I had copper and nickel electrodes and .1M copper sulfate ...
24 views

### How to prevent feasibility of intermolecular attack of 1,2-diol?

I was given a problem that requires me to synthesize (1R,2R)-2-methoxycyclohexanol from cyclohexene. I tried it with syn-hydroxylation of alkene $\pi$ bond with $\ce{OsO4}$ and NMO then directly ...
25 views

### Robinson annulation mechanism [on hold]

How do I start a mechanism to find the product? I started by deprotonating the alpha proton but I don’t know what’s next
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### What's the percentage of Thallium in those low temperature thermometer? [on hold]

Also, what's the solubility and volatility of that compound, and how toxic it is?
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### Calculate voltage, cost and time of nickel coating

To nickel with a bath of $\ce{NiSO4}$ a cathodic current of $\pu{0.3 A/cm2}$ is applied with a square plate of side $\pu{5 cm}$ is used to nickel a certain substrate. Due to the formation of $\ce{H2}$ ...
680 views

### What is the difference between chemical equilibrium and dynamic equilibrium?

Is chemical equilibrium and dynamic equilibrium the same thing? Both point to the reversible reactions and no net changes in the concentrations of product and reactant. Dynamic equilibrium from ...
47 views

### Determining heat capacity of gasses

I need a little help on answering a question which popped into my head while I was reading about gas laws: Suppose that I have three canisters, each holding a different gas of unknown identity [...
51 views

### Organic Chemistry - Effect of methyl substituent in Aromatic Substitution via Benzyne

The following reaction has been taken from my study material. This shows that the benzene ring is undergoing a nucleophilic aromatic substitution via benzyne mechanism (presence of a strong base like \$...
47 views

### Order of paramagnetism among nitrogen, oxygen, aluminium and calcium [on hold]

Which of the following arrangements show a decreasing order of paramagnetism? a.) N > Al > O > Ca b.) N > O > Al > Ca c.) O > N > Al > Ca d.) O > N > Ca > Al The answer was b. Although I ...

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