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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
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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
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 ...
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Can a carbocation be isolated?If yes then how many of them have been isolated? [closed]

Carbocation stability, organic chemistry knowledge
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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 ...
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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 ...
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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 ...
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 ...
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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 ...
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 ...
187 views

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
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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....
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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 ...
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 ...
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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 ...
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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 ...
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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}...
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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 ...
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? (...
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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?
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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 ...
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.
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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 ...
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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 ...
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 ...
26 views

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

why is energy released when a chemical bonds is formed?