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-1
votes
0answers
18 views

How to determine N-terminus and C-terminus of a protein

If one takes away the “$\ce{NH2}$” and “$\ce{COOH}$” on the image given, how would someone be able to determine which side is the N-terminus and which is the C-terminus with only the amino acid groups ...
-4
votes
0answers
23 views

Chem 101 Molarity/Mass conversion

A person suffering from hyponatremia has a sodium ion concentration in the blood of 0.116 M and a total blood volume of 4.9 L. What mass of sodium chloride would need to be added to the blood to bring ...
-1
votes
0answers
13 views

How does the stability of Group I and Group II carbonates change as you descend the groups?

I thought that as you descend both the groups, the carbonates get more stable. Is this because of the ions decreasing in charge density down the groups (so less distortion for the carbonate ion) so ...
-1
votes
1answer
19 views

Diamagnetic vs Paramagnetic

As far as I know, to know whether a substance is paramagnetic or diamagnetic, we check if that particular species has got unpaired electron or not. But my textbook lists- Examples of Diamagnetic ...
1
vote
1answer
26 views

How to find the Cp, difference of Cp and heat of fusion from the dependence of vapor pressure on temperature?

The vapor pressure of zinc varies with temperature as $$\log P(\pu{mm Hg}) = -6850/T - 0.755\log T + 11.24 \label{eqn:1}\tag{1}$$ and that of liquid zinc as $$\log P(\pu{mm Hg}) = -6620/...
0
votes
0answers
33 views

Acids, Molarity and Titration: Finding Volume [on hold]

If the lemon juice used has 0.121 mol of total acid per 100. mL of juice, what volume (in mL) of 0.0998 M NaOH would you use to reach the endpoint of the titration?
1
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0answers
30 views

How to I find the equilibrium temperature in this problem?

From Castellan's Physical Chemistry, chapter 12 [1, p. 276]: 12.18 At $\pu{25 °C}$ we have for rhombic sulfur: $ΔG_\mathrm{f}^\circ = 0,$ $ΔS^\circ = \pu{31.88 ± 0.17 J K-1 mol-1};$ and for ...
0
votes
0answers
25 views

Analytical chemistry exercise [on hold]

The iron present in a $\pu{0.6656 g}$ sample of a mineral was reduced quantitatively to the $\ce{Fe^2+}$ state and subsequently titrated with $\pu{26.75 mL}$ of $\ce{K2Cr2O7}$. Calculate the ...
2
votes
1answer
31 views

Help in drawing resonance structures in case of polybasic acids

While drawing resonance structure of dibasic or tribasic acid, e.g. should I take out two $\ce{H+}$ (in dibasic) or three $\ce{H+}$ (in tribasic) together or one by while drawing resonance structure? ...
1
vote
3answers
38 views

Photoelectric effect (AP Chemistry question)

Which of the following postulates regarding the photoelectric effect is considered to be INCORRECT according to the quantum mechanical model we currently understand? (A) Increasing the intensity ...
-2
votes
1answer
27 views

What is the solubility of Group 1 sulphates?

& is there a trend? (I know that the solubility of the hydroxides and carbonates increase down Group 1, because they have a single charge(?))
-1
votes
1answer
20 views

Redox Titration in investigating change of Iron in Avocado

I'm trying to investigate the change in iron in an avocado as it ripens. I'm planning on using redox titration but still a bit unsure of how to carry out the investigation (method). Do you have any ...
2
votes
1answer
29 views

What is the number of stereoisomers for hex-4-en-2-ol?

For the following compound, find Total number of stereoisomers Number of optically active stereoisomers Total number of fractions on fractional distillation of all stereoisomers ...
-1
votes
0answers
9 views

Will molar concentration affect heat of neutralization of weak acid?

We did an experiment on neutralization of acids where we used 50% g/ml of NaOH to neutralize 0.5 M of acetic acid. I got the heat of neutralization to be -27.441 kJ/mol and theoretically it's 55.43 kJ/...
0
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0answers
20 views

How to synthesize iron acetate from Iron chloride [on hold]

This is the Practices I use: Iron ii chloride was converted to hydroxide by adding NaOH, and then I added acetic acid to give the Fe 2 O 3 compound (with strong stirring and a temperature of 80-100 ° ...
2
votes
0answers
9 views

Chemical interaction between Pterostilbene and Nicotinamide Riboside

Some supplement companies are putting a combinations of nicotinamide riboside and pterostilbene into the same capsule. Considering the stomach acid, water, body temperature, etc. I am wondering if ...
4
votes
0answers
35 views

Timescales in Chemical Analysis

Has anyone seen a comparative list of typical run times of the techniques used in analytical chemistry? I am making a list of rough timescales of analytical techniques (for a slide). For example: ...
-1
votes
0answers
11 views

Calculate the final temperature [on hold]

Calculate the final temperature of 34 mL of ethanol initially at 20 ∘C upon absorption of 617 J of heat. (density of ethanol =0.789 g/mL) answer in two sig fig
0
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0answers
20 views

ZnSe and Carboxylate [on hold]

As part of an experiment, I need to immerse a piece of ZnSe crystal into a glass that contains a solution of water and carboxylate microspheres. I just want to make sure that the carboxylate will not ...
0
votes
0answers
18 views

Comparing Polarity of Amino Acids [on hold]

I know that there are polar uncharged amino acids (serine, threonine, asparagine, glutamine, cysteine) and polar charged amino acids (the basic and acidic amino acids). Does the charge on the acidic ...
0
votes
0answers
22 views

Comparing theoretical to experimental values for standards using calibration curve

I prepared 4 standards of increasing concentration. After they were measured, I plotted the absorbance vs the ppm. If I want to determine how far off the actual concentrations are from the expected ...
0
votes
0answers
18 views

Problem with Electrodes and Electrochemical Cells

If you were doing a coulometric acid titration and the electrodes were ONE beaker without a salt bridge, what would the problem be if both of the electrodes in the beaker were graphite?
0
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0answers
10 views

Lithium carbonate resistivity [on hold]

Does anyone have at least rough idea of the resistivity or conductivity of molten lithium carbonate?
-1
votes
0answers
12 views

Melting point of almond milk [on hold]

Okay, let me ask this one more time. I have some almond milk and I saw it freeze partly in the refrigerator I suspect that it was able to freeze because the almonds dissolved in the water were an ...
0
votes
1answer
12 views

Intuition for why effective nuclear charge increases down a column

My textbook (Chemistry the Central Science, edition 12, Brown et al.) says that effective nuclear charge increases down a column. Indeed, this is consistent with the values provided by Clementi in the ...
-2
votes
0answers
19 views

Naming Molecular and Ionic Compounds [duplicate]

There's something about Chemistry that I need to clear up. Naming compounds. So I heard that there are different ways to name a compound depending on what it is. But I can't keep track of it all! ...
3
votes
0answers
26 views

acid strength: Periodic trends vs delocalisation, which one is more important

In 1st year chemistry questions, the concept of acid strength is often introduced to students including the 3 factors that provide a heuristic explanation for most of the common acids and conjugate ...
-1
votes
0answers
10 views

Why is there a general decrease in melting point down the group 2elements [on hold]

Hi please guys help me answer this query
0
votes
0answers
33 views

Explain this Acidic Strength order H2SO4>HCl>HNO3 in acetic acid?

Explain this Acidic Strength order H2SO4>HCl>HNO3 in acetic acid ? My Attempt Stability of Conjugate base is proportional to the acidic strength of Acids in acetic acid. 1)SO4- is having 2 ...
0
votes
1answer
60 views

Can the plane of symmetry for a compound be the plane of the paper?

1,4-Dichloro-2,5-dimethylbenzene is symmetric about the plane of paper. I have never seen a plane of symmetry positioned like this. Would it be correct to call it a plane of symmetry?
-1
votes
0answers
28 views

Which atomic/molecular theory do we use in biology? [on hold]

We have all learnt different chemical theories (bohr model, quantum model etc) with the new theory being more correct than the previous ones. Suppose I do research in biology, how would I choose the ...
0
votes
0answers
18 views

Can Lugol's iodine differentiate between saturated/unsaturated fats?

We conducted an experiment involving Lugol's iodine where if a substance contained a lipid it would form concentrated areas of color on the sides of the test tube. On many occasions, the test would ...
-1
votes
0answers
16 views

Why is inert pair effect not applicable for d block elements?

In the 4B group as we go down the group the stability of +5 oxidation state increases. Shouldn't it decrease due to inert pair effect?
1
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0answers
13 views

electrolysis in aqueous solution. Why is hydroxide discharged at the anode when no halide ions are present [on hold]

Why are hydroxide Ions discharged when halide ions aren’t present in aqueous solution during electrolysis
1
vote
1answer
35 views

Confusion about comparing the charge densities of benzene and fluorobenzene

I understand that the functional group $\ce{-F}$ is an electron-withdrawing group. It is expected that the difficulties of an electrophile to attack the carbon atoms are $$\ce{PhH}<\ce{2,4of PhF}&...
2
votes
1answer
41 views

Is carbon dioxide soluble in petroleum ether, and why?

I googled it, and I'm finding some forum posts that say no, but no authoritative reference. CO2 is somewhat soluble in water (1.7 g/L at 20°C) and I understand that it's mostly NOT because it forms ...
0
votes
1answer
25 views

Vinegar salt reaction to produce acid; does it matter what type of vinegar I use

I am trying to get get hydrogen chloride gas by using the reaction sodium chloride + vinegar = HCl(g) + sodium acetate, does it matter what type of vinegar I use eg apple cider vinegar, malt vinegar; ...
2
votes
1answer
35 views

Metal nail reaction in wall filler

Please help explain what is happening to this nail. It has been in this wall filler for a good few months. The substance being excreted was rising up forming these stalagmites, with a liquid forming ...
-2
votes
0answers
5 views

Calculate protein concentration based on Lowry assay [on hold]

Calculate the UNKNOWN protein concentration based on Lowry assay method. A standard curve was plotted and the amount of protein added in the unknown protein concentration was calculated based on abs ...
0
votes
0answers
10 views

SN2 reaction on a chiral carbon atom [on hold]

What would the mechanism for the treatment of a chiral carbon atom in an SN2 reaction be like. And can you please explain SN2 reaction briefly Thank you
-1
votes
0answers
16 views

What is the N factor of sulphur trioxide and sulphur dioxide in various reactions

As such i got my concept clear in case of redox reactions , but i fail to find n factor for non redox reaction specifiallyin case of $\ce{SO2 ,SO3}$ , where i used the total.+ charge or total - chrge ...
1
vote
0answers
19 views

When alcohol is used to sterilize, what about it changes that it can't be re-used? [on hold]

I read online that when you use regular household rubbing alcohol to soak something for sterilization purposes, you're then supposed to toss it out. I'm just curious why. Like, as long as there's a ...
-1
votes
0answers
34 views

What is $\ce{NHO3}$? [on hold]

Are $\ce{HNO3}$ and $\ce{NHO3}$ the same compounds? If not, what are the differences between them? If so, is one order preferred over the other? Are both acceptable?
2
votes
1answer
130 views

Does CO2 form carbonic acid in the atmosphere?

Since when $\ce{CO2}$ goes into water it makes carbonic acid, then what happens when it rains? Some of the $\ce{CO2}$ in the air joins the rain drop as it falls and while the rain drop falls and ...
1
vote
0answers
16 views

Making Lyophilized Cake Lookalike using household ingredients

I'm working on a machine learning model to identify flaws in vaccines in lyophilized cake form. To train the model, I need a number of samples that look something like this: I have vials, but I'm ...
1
vote
0answers
17 views

styrene confusion

I am studying NMR and while looking at styrene, I can't figure out why the two hydrogens on the terminal double bond are not equivalent. Is it because one is closer to the ring in position than the ...
1
vote
1answer
27 views

What will be produced when sucrose and potassium bitartrate react with each other?

What would happen if sugar and cream of tartar react with each other? Would it create an ester? $$\ce{KC4H5O6 + C12H22O11 -> KC16H21O14 + 3H2O}$$ Is this correct? If not, why?
-1
votes
0answers
18 views

Is there a molecule in which the central atom makes 8 bonds and has an hybridization of sp3d? [on hold]

Doesnt matter what the molecule is, but the central atom has to be sp3d and make 8 bonds
1
vote
0answers
34 views

What reactions involving hydrazine, dinitrogen tetroxide and possibly a contaminant can produce a salt?

Hydrazine $\ce{N2H4}$ and dinitrogen tetroxide $\ce{N2O4}$ form a hypergolic fuel and oxidizer pair widely used in spacecraft including Akatsuki. Wikipedia states: Hydrazine can be monoprotonated ...
0
votes
0answers
12 views

When is the concentration in which you put into the equilibrium constant equal to 1 for solids and liquids?

There are many websites which states that pure liquids and solids have a concentration equal to one, but for some equations they are not! How do you explain the difference for this equation? For the ...

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