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4 views

Why does group 1 metals have a negative electron affinity whereas group 2 has a positive electron affinity [closed]

Electron Affinity is defined as the energy change when an electron is gained by an atom
-1
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0answers
4 views

Heat exchanger area calculation [closed]

i got this question from my test but i do not know the answer, could someone help me solve this problem please. thank you
1
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0answers
10 views

what will the products be when AgNO3 reacts with [Cu(NH3)4(H2O)2]2+?

I'm trying to increase the pH of the $\ce{AgNO3}$, the only way was using complexation of ammonia and decided to use $\ce{[Cu(NH3)4(H2O)2]^{2+}}$. The only problem is that I don't know if this complex ...
-2
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0answers
10 views
0
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0answers
11 views

Chlorine degradtion

I am using Sodium dichloro-S-triazinetrione tablets to make sanitizing solutions (approximately 200 ppm available chlorine) and disinfecting solutions (approximately 800 ppm available chlorine). Per ...
5
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1answer
38 views

Can ferrocene type sandwich compounds be made with fluorene?

Ferrocene will be well known to made members of this site. It consists of two cyclopentadienyl anions sandwiching an iron-II ion. During my first year organic chemistry course (about 40 years ago) I ...
-2
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1answer
41 views

Why is it that when I add yolk to vinegar and olive oil, it doesn't create a stratification?

Why is it that when I add yolk (which mostly consists of minerals, vitamins, lipids and proteins) to vinegar and olive oil, it doesn't create a stratification? I'm really confused about this because ...
0
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0answers
22 views

How can I measure the changes in intensity of chemical bound signals between radiated and non-radiated samples?

So, If I have data of intensity of chemical bound signals fixed on every wave length for radiated and non radiated samples, then how can I apply FTIR quantitative method, in order to show how great ...
6
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1answer
49 views

What is nowadays called silazane?

Example from the Recommendations 2013. Left: Alleged disilazane ; Right: My version Clearer example without obvious flaws in alternative structure. Left: Alleged disilazane ; Right: My version I am ...
1
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0answers
22 views

What is the materials science behind thermal diffusion in multispectral camouflage?

I've been interested in infrared and near-infrared camouflage (called multispectral camouflage) for a couple of days now, and I've found a video or two of certain companies that have created fabrics ...
4
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3answers
187 views

Why was Avogadro's number chosen to be the value that it is?

I understand that the mole is an extremely useful way of measuring and understanding atomic quantities. However, I can not find anywhere on the web why is it, that Avogadro's number was chosen as $6....
-2
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0answers
22 views

Why does changing the pressure not affect the yield of hydrogen at equilibrium? [closed]

I have an equation for a reaction to produce hydrogen: $$\ce{CO_{(g)} + H2O_{(g)} <=> CO2_{(g)} + H2_{(g)}}$$ Could you help me to understand why changing the pressure does not affect the ...
-1
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1answer
38 views

What does the value of the pH meter mean when there aren't any hydronium ions in the substance being tested?

What does the value of the pH meter mean when there aren't any hydronium ions in the substance being tested? How does the pH meter show a value which fluctuates as non-aqueous solvents are being ...
2
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2answers
26 views

In free radical substitution of propane with halogens, how do you know which carbon ends up with an unpaired electron after fission of C-H bond?

In free radical substitution of propane with a halogen (eg- chlorine), how do you know which carbon out of the three ends up with an unpaired electron after fission of C-H bond? This image shows ...
0
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0answers
15 views

What kind of reaction is this? Hydrated copper sulphate [+heat energy] <=> anhydrous copper sulphate + water [closed]

I'm quite new to chemistry and just need to know what type of reaction this is. hydrated copper sulphate [+heat energy] <=> anhydrous copper sulphate + water
3
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5answers
208 views

How to create black precipitate in clear liquid

I am not a chemistry person at all, so my apologies if my question seems dumb. I am working on the set for a short film and in one of the scenes we would like the main actor to look at a sample of ...
0
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1answer
39 views

The amount of heat energy required to raise the temperature of 1g of helium at NTP from T1 K to T2 K is?

The amount of heat energy required to raise the temperature of 1g of helium at NTP from $T_1 \pu{K}$ to $T_2 \pu{K}$ is? My confusion is, that as the gas is at NTP, therefore, it is an isochoric ...
-4
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0answers
21 views

Difference in chemical composition between black, white and green bin bags [closed]

I notice that generally speaking black bin refuse sacks have a very strong smell. White bin liners have a similar smell though much lighter smell. Green bags which I believe are refereed to as ...
0
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1answer
26 views

What would be the aldol condensation products in B

In this question (13) I figured out A,C were wrong and D would be correct choice but I am stuck at finding out products formed in B and also why it would be wrong? Please help.
2
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1answer
21 views

Connection between irreducible representations and electronic states in diatomic molecules

I am trying to understand the connection between irreducible representations and molecular electronic states. To explain the problem: I found some potential energy curves (PECs) for $\ce{N2+}$ in the ...
0
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0answers
27 views

Is there some way to predict the sign of Gibbs free energy of formation of a compound?

I read that the Gibbs free energy of formation of benzene is around $+100 kJ/mol$. Since the Gibbs free energy of formation is positive, benzene is thermodynamically unstable and has a spontaneous ...
0
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0answers
18 views

Is there any effect on bonds formation and reactants due to a reaction in adiabatic calorimeter

Is there any effect on reactants and bond formation due to a reaction going on a adiabatic calorimeter.We know enthalpy of a reaction should be measured at constant temperature but in adiabatic ...
-1
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1answer
17 views

Partial pressure and stoichiometry

CH3CHO -> CH4 + CO If the required partial pressure of CH4 is given, is it possible to say that CH3CH0 has the same partial pressure because it is a 1:1 ratio?
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0answers
17 views

Finding the concentration [closed]

How many mL of a 0.250M sodium hydroxide solution is needed to neutralize 25.0 mL of a 0.430M sulfuric acid solution? 29.5 mL 43.7 mL 86.0 mL
1
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0answers
32 views

Mechanism of Possible Acid Catalysed Ring Opening

Here's a problem I'm stuck with - The first step looks like the usual addition of hydroxylamine to the ketone, resulting in two diastereomeric oximes (this is probably what (A) is). Further, in the ...
-1
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0answers
13 views

What is the Theoretical Yield [closed]

Which is the theoretical yield (in g) of Ca(OH)2 that can be formed when 3.00 g of calcium are reacted with 8.00 g of water to produce hydrogen gas in the following equation? Ca(s) + 2 H2O(l) → Ca(OH)...
1
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1answer
25 views

Help with molecular dynamics and computational modelling to check validity of hypothesis regarding SN2 reaction mechanisms [closed]

Polar aprotic solvents have a less hindered electronegative atom pointing out, namely oxygen, fluorine, and nitrogen, all of which have lone pairs besides having a partial negative charge. Now, all ...
0
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1answer
24 views

Chirality and number of sterioisomers

I have recently read that the number of sterioisomers in a compound having n chiral centres is 2^n. (That is, if no meso form is present) The below question asks for the number of sterioisomers in ...
0
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1answer
38 views

What you understand by “Order of reaction”? [closed]

When studying Kinetic chemistry (and most of the Physical chemistry topics), we often find definitions based upon the mathematical formalism. For example, Order of reaction is often defined as the sum ...
-2
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0answers
26 views

Regarding the rarely found(on web) and taught concept of variation [closed]

My question is regarding the rarely found(on web) and taught concept of variation. Suppose we have 2 physical quantities A & B which can be measured in their respective units. Since we can ...
-1
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0answers
10 views

why -I groups are meta director? [closed]

in benzene if a EWG is placed then why it is meta directive not para directive since -I effect will be minimum at para position
0
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0answers
59 views

Is it possible to synthesize a benzene ring with every carbon on the ring substituted?

We recently began covering aromatic electrophillic substitution in my first year organic chemistry course, and we've been discussing the nature of certain functional groups being activating $(\ce{-OH},...
-4
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0answers
52 views

WHAT IS mole concept [closed]

i am finding stoiciometry tougher. i dont understand what is mole concept. How it is related to molar mass, atomic mass unit, gramper mole. Please explain
4
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1answer
24 views

Combination of polydisperse polymer mixtures

Say I'm given a mixture of batches of polydisperse polymers. I know the weight $w$, the number average $ \bar M_n$, and the weight average $ \bar M_w$ of each batch that was added to the final mixture....
-1
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0answers
20 views

Why does cyclopropane have a higher melting point than propane? [closed]

Ok so I've read that cyclopropane has a higher melting point ~-128°C than propane ~-188°C (Courtesy: Wikipedia). Now I know that cyclopropane is more compact and therefore it's lattice is more stable ...
1
vote
1answer
43 views

How to compare the rate of decarboxylation?

For the following acids compare the rate of decarboxylation on heating I $\ce{Ph-CO-CH2COOH}$ II $\ce{Ph-CO-COOH}$ III $\ce{CH3-CH2-COOH}$ IV $\ce{HOOC-CH2-COOH}$ I tried this ...
3
votes
1answer
40 views

Why do the splittings in mirrored COSY crosspeaks differ?

I have a COSY spectrum of a mixture of butanal and butyl bromide and I don't understand why the cross-peaks have various/different splitting on the other sides of the diagonal. I think it may have ...
0
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1answer
40 views

XRD Peaks in databases

I had a look at the JCPDS card of BiOCl and saw that there were very small peaks (such as 0.1 percent relative intensity) that I think wouldn't be observed in XRD pattern, they would just blend in ...
-1
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0answers
30 views

Relative error on a single density measurement [closed]

I determined the density of a coin, using a ruler with an uncertainty of ± 0,1 cm, and a balance with an uncertainty of ± 2 g. The volume relative error is $$ \dfrac{\Delta V}{V} = 2 \dfrac{\Delta l}...
2
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0answers
17 views

Vibrational modes in BiOCl

These are the vibrational modes in BiOCl. I'm trying to account for the each mode, and where in the spectrum you would find such mode. And I found out that at 1400 cm-1 you have asymmetric stretch of ...
-1
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0answers
18 views

How to determine which molecule is planar? [duplicate]

I've been having difficulty in this particular question for some time, primarily because I have no idea how the correct option was arrived at: Which of the following is not a planar molecule? (...
-2
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1answer
39 views

Can grignard reagent be with CN group? [closed]

is CN--Mg--Br possible?? and can it be used to attach CN- group to alkanes with O= group attched to them already?
-6
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0answers
25 views

From your graph determine the pKa value for this weak acid and report it in Blackboard to 2 decimal places [closed]

Use the data provided to graph the titration curve for 50 mL of a 0.4 M weak acid solution titrated with 0.45 M NaOH solution. From your graph determine the pKa value for this weak acid and report it ...
0
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0answers
15 views

Siloxane permeable to oxygen but not water

I want to purchase a siloxane plastic that is permeable to air but not to water. Any suggestions for what I should ask for, or are all waterproof silicon plastics permeable to air? Thanks.
0
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0answers
31 views

Carbon compounds with no covalent bonds [duplicate]

The first line of the Wikipedia article on Organic Chemistry says: "Organic chemistry is a subdiscipline of chemistry that studies the structure, properties and reactions of organic compounds, which ...
3
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1answer
82 views

Application of the electronegativity effect on bond angles

There's a rule in determining molecular geometry that says that if the electronegativity of the central atom increases, the bond angle of the molecule increases. Is this is only applicable in the ...
2
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1answer
52 views

Benzyl Carbocation Stability: Would electron-withdrawing group on the ring destabilize the carbocation?

In the following question I need to decide whether the reaction would undergo SN1 reaction or SN2 reaction. I initially thought it would be SN1 since the resulting benzyl carbocation can be ...
-2
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1answer
26 views

why is energy released when a chemical bonds is formed? [closed]

why is energy released when a chemical bonds is formed?
-2
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0answers
26 views

Stabilized Chlorine Dioxide rations and it vs Lauryl Benzyl Ammonium Chloride [closed]

If you don't mind me asking about stabilized chlorine dioxide(2% solution). FOR THE INTEREST OF SAFETY AND MAKING SURE PROPER USAGE IS OBSERVED, maximizing efficacy. What is the correct ratio for it ...
-3
votes
1answer
40 views

How to detect unknown contaminants in water? [closed]

Let's say that I have 1 Liter of 100% pure water. A gremlin may or may not have added an unknown amount of an unknown substance and then drained the volume until it returned to 1 Liter. I'm not told ...

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