All Questions

0
votes
0answers
3 views

Understanding Photo-chemical reaction variables in a photo-reactor

We are designing a lab that is based on photochemical reactions, but we have not learned about photochemical reactions in class, so I just wanted to get a better understanding of photochemical ...
1
vote
0answers
12 views

Free induction decay in NMR (as stated in Pavia)

There is a statement in a very popular textbook of spectroscopy by Pavia (Chapter 3, Intro. to Spectroscopy), it says "The observed FID is actually an interference signal between the radiofrequency ...
-2
votes
2answers
17 views

Is acetanilide more soluble in water than diethyl ether?

Would acetanilide be more soluble in water at 25 degrees Celsius because it has an N-H and an oxygen that can participate in hydrogen bonding whereas diethyl ether only has an oxygen?
-2
votes
0answers
20 views

Software for conformational search [on hold]

I need a free software to perform a conformational search on molecules with 10 to 16 rotational bonds. What software would you recommend me? Where can I download it? Where can I find a manual of this ...
-2
votes
0answers
11 views

Which of the following ion will form most water soluble hydroxide? (A) K+ (B) Ni2+ (B) Zn2+ (C) Al3+ [on hold]

Which of the following ion will form most water soluble hydroxide? (A) K+ (B) Ni2+ (B) Zn2+ (C) Al3+
-1
votes
0answers
14 views

Why does anisole not hydrolyze in water solvent at low temperatures?

As per what i learnt about ethers hydrolysis, the oxygen protonates itself first and then the water and then water being a weak nucleophile, we first prefer the ether to cleave from either side to ...
0
votes
0answers
24 views

Water Gas Shift Reaction [on hold]

For the extremely important water gas shift reaction shown below, the $K_c = 3.491$ at a certain temperature. What are the equilibrium concentrations of all the components of the reaction if $\pu{0....
0
votes
1answer
36 views

What units of K should we use in ΔG=-RTlnK?

I understand that $K$ will be dimensionless. Let's say an equilibrium involving $K_p$ and the reaction is $\ce{A -> B}$, $K_p$ will be dimensionless. If the reaction $\ce{A + B -> C}$, then ...
1
vote
4answers
34 views

What kind of system is required for dynamic equilibrium to be set up?

Most websites and books mention a closed system, but technically isn't an isolated system required? If energy can be transferred, then the position of of the equilibrium will continuously change and ...
-1
votes
0answers
22 views

Type of energy stored in links between two atoms [on hold]

What type of energy is stored between link of two atoms? 1] Thermal energy 2] Nuclear energy 3] Chemical energy 4] Potential energy
-1
votes
0answers
14 views

Are reactive and active exactly the same terms in EAS?

I have understood the two terms as: When we say that a substituted benzene ring is reactive we mean the same thing as calling the reaction of potassium and water highly reactive. When we call a ...
-1
votes
0answers
12 views

Confused in hybridisation [on hold]

I stumbled upon a compound [Ni(Nh3)6] ^2+ which has Nh3 as a strong field ligand. Which implies that pairing will occur and only one last d-orbital will be left with no electrons. But I couldn't ...
0
votes
0answers
13 views

Oxidation reaction of dimethylselenide / Selenourea with hydrogen peroxide

For my paper, I need to find the reaction between $\ce{(CH3)2Se2}$ and $\ce{H2O2}$ and between $\ce{SeC(NH2)2}$ and $\ce{H2O2}$. The mechanism below shows how I think it goes. The reaction should ...
-1
votes
0answers
15 views

Calculation of no. Of stereoisomers

I am confused as how to do the ques , should i take the ring as a single stereocentre or should i consider the no. Of single bonds about which the groups are showing GI in the ring.(https://i.stack....
1
vote
0answers
22 views

Find the increasing order of formation of ortho product

Find the increasing order of ortho product formation when Y is (i) F, (ii) Cl, (iii) Br, (iv) I. We know that halides are ortho, para directing for EAS reactions and we consider the electronic ...
0
votes
0answers
16 views

Does the anode become negative?

Electrolysis: If anions continue to deposit electrons on the anode, does this mean after a while the anode becomes negative? If not how is the anode discharged from it’s electrons
1
vote
0answers
24 views

Resonating structures of (pentan‐2‐ylidene)oxidanium

Draw resonating strictures of the following compound: In this molecule there are two π-components, but they are not conjugated. According to me, as there is no conjugation, it should not have a ...
-3
votes
0answers
18 views

About transition metals [on hold]

Transition metals have a number of properties where they differ from other metals in the periodic table. Discuss these differences in terms of high densities, high melting and boiling points, ...
2
votes
1answer
30 views

Synthetic ruby - damaged by heat less than its melting point?

A bit of a jewellery question but chemistry related. I want to encase a synthetic ruby (corundum, Al2O3) in silver by melting the silver around it. Either in a furnace or by casting. The MP of silver ...
0
votes
1answer
37 views

What is the mechanism of the reaction of a ketone with sodium nitrite/ hydrogen chloride?

What is the mechanism of reaction of a ketone with $\ce{NaNO2/HCl}$? Can $\ce{NaNO2/HCl}$ be considered as freshly prepared $\ce{HONO}$ here? I am confused about how the reaction will proceed.
0
votes
0answers
28 views

What does it mean that packing fraction is maximised?

I am having a issue with terminology with regards to packing fraction: $$\frac{\text{Number of atoms} \times \text{Volume of atom}}{\text{Volume of unit cell}}$$ But I was recently reading a solid ...
1
vote
1answer
24 views

Meaning of polarization pulse in microwave (rotational) spectroscopy

In the recent rotational spectroscopy literature, "microwave polarization pulse" is often used in conjuction with pulsed Fourier transform microwave spectroscopy (Google Scholar). Sometimes the pulse ...
0
votes
0answers
43 views

Reaction of ketones with sodium amide

Find the product of the reaction of dimethyl ketone i.e. $\ce{CH3C(O)CH3}$ with $\ce{NaNH2}.$ Should I do nucleophilic addition and form the product in the picture??
-2
votes
3answers
40 views

ICE table with changing volume without Kc [on hold]

Just having trouble understanding how to approach an ICE table question with no Kc and a volume change Given If you had 4.4 mol of a solid, A, placed in a 1L container which decomposed in to B and ...
1
vote
0answers
8 views

Deposition of Nb on SiO2 wafer (Z-Cut)

I am trying to sputter $\ce{Nb}$ on $\ce{SiO2}$ Z-Cut wafers (quartz crystal). I was wondering if $\ce{Nb}$ will stick well to the surface of the wafer. I've routinely deposited $\ce{Nb}$ on $\ce{...
-3
votes
0answers
24 views

What methods are used to detect a particular molecule? [on hold]

What methods are used to detect a particular molecule? I know of raman spectroscopy and "test" reactions (forming coordination complexes, iodine starch test, silver mirror test etc.)
1
vote
1answer
31 views

Thickening and/or slowing evaporation of IPA-based ink

The conundrum I have a security printing ink that I make by adding an IR-absorbing dye to a 50/50 mix of Isopropyl Alcohol and distilled water. The ink solution is pale green but dries virtually ...
0
votes
0answers
32 views

How do I identify the compound(s) that formed from a failed synthesis of another compound?

A general answer to the question is great, but specified to my problem is very much welcomed. My team had a lab project — to synthesize chrome alum crystals. We first dissolved $0.3 \, \rm g$ of ...
0
votes
0answers
15 views

Would two different Plaster of Paris samples have different chemical signatures?

Weird question, but... would a spectroscopic analysis of a plaster of Paris sample reveal a chemical identifier that could be used to compare that sample against another. I want to be able to say ...
-2
votes
0answers
42 views

Find average rate of the reaction based on decrease of reactant's concentration

A reaction happens where $\ce{A}$ is converted into $\ce{B}$. It takes $\pu{4 min}$ for the concentration of reactant $\ce{A}$ to decrease from $\pu{3.0 M}$ to $\pu{1.0 M}$. What is the average rate ...
0
votes
0answers
13 views

Determing wheter a particle is stable with respect to strong and electromagnetic reactions [on hold]

Given the decay $Λ_b(5620) → K^− + P_c(4380)+ → K^− + J/ψ + p$ I was asked as a homework question , to consider all hadrons containing b quarks, to determine whether $Λ_b(5620)$ is stable with ...
4
votes
1answer
31 views

Why is the graph of fluorescence vs. wavelength continuous?

If the emission of a photon from an excited state to the ground state occurs with a precise energy, then why is it that wavelengths that differ from lambda max have values on a fluorescence vs. ...
7
votes
1answer
354 views

Can the van der Waals coefficients be negative in the van der Waals equation for real gases?

A gas described by van der Waals equation has the pressure that is lower than the pressure exerted by the same gas behaving ideally. True or false? My approach $$P(\text{ideal}) = P(\text{real}) + P(...
-2
votes
0answers
25 views

Using Delta G to find melting/boiling points of compounds? Help [on hold]

So I decided to have some fun using the concept of Delta G to see if i can calculate melting points and boiling points for compounds. I was looking at the following reaction: NaOH(S) --> NaOH(l) I ...
-1
votes
0answers
13 views

Butan-2-ol to Butanone using only H2SO4 as oxidising agent

Is it possible to oxidise the alcohol in question with just concentrated H2SO4 (without the need for a Chromic substance) and if so what does this mechanism look like?
0
votes
2answers
48 views

The equivalent weight of HNO3 in the following reaction [on hold]

The equivalent weight of HNO3 in the following reaction is ‘x’, then the value of x/21 is 3Cu+8HNO3⟶3Cu(NO3)2+2NO+4H2O in this I atempted by using redox formulas but my answer is comming 1 but ...
0
votes
0answers
15 views

Friedel Crafts Acylation: Reaction of acyl halide with catalyst

To form an electrophile for this reaction to occur, the acyl halide interacts with the catalyst. However, on reviewing the conditions for the reaction, I have encountered that the 2 equivalence of the ...
0
votes
0answers
7 views

Rate of nucleophilic addition reaction of carbonyl compounds

How should I compare the order of rate of 1.formaldehyde 2.ethanal 3.p-nitrobenzaldehyde 4.p-methoxybenzaldehyde For nucleophilic addition the rate depends on the intensity of electron deficiency of ...
3
votes
1answer
45 views

Why is casein hydrophobic?

According to this source hydrophobic behaviour occurs when a molecule does not have a charge or is neutral and therefore cannot be attracted to the negative nor positive parts of water. Casein has an ...
2
votes
1answer
32 views

Derive expression for heat flow from oil bath to metal sphere

A spherical ball of iron is put into a hot bath of oil. The iron ball is initially at a low temperature and heat transfer from the oil to the iron will increase the temperature of the iron ball. ...
-1
votes
0answers
16 views

Concentration Conversions [on hold]

I did an experiment trying to calculate how much energy was used to evaporate water with different ammounts of NaCl. In the experiment, I put 71g of NaCl then filled the beaker with water to the ...
-1
votes
1answer
33 views

Why does color change during chemical reactions? [on hold]

I asked this question somewhere and I got the answer as the the very fundamental arrangement molecules changes which leads to different optical properties of the substances. I can't express the ...
-1
votes
0answers
9 views

Do fabrics assimilate airborne dioxins? [on hold]

Do natural or synthetic fabrics (clothing, etc) dissolve/trap dioxins and dioxin-like compounds from third-party/external sources such as airborne plastic fumes or soot? Also, is it safe to assume ...
-1
votes
1answer
23 views

pH of a Calcium Hydroxide vs Magnesium Hydroxide solution [on hold]

In an AQA 2017 Chemistry paper, a $0.0131 \pu{mol}\cdot\pu{dm^-3}$ saturated solution of calcium hydroxide is prepared and then the question asks to predict the pH of a similar solution of magnesium ...
-6
votes
0answers
15 views

Amount of moles [on hold]

Using the molarity of sodium hydroxide (0.50M) and the volume of sodium hydroxide used to find the equivalence point (13.5mL), determine the moles of sodium hydroxide used.
-1
votes
0answers
16 views

Can dioxins be absorbed through the skin? [on hold]

I am aware that excessive/long-term exposure to dioxins dioxin-like compounds can cause skin problems (chloroacne) and their great affinity to lipids/fats, but I was wondering if the same occurs at ...
-2
votes
0answers
35 views

how to count total number of stereo isomers?

please see the question below(i don't know how to approach question my teacher just told me to use the formula 2^n where n are number of chiral carbons but it doesn't work always please can some one ...
1
vote
1answer
23 views

Solubility of Iodine in different solvents

The solubilities of iodine in $\ce{CCl4,n-Hex,Et2O,PhCH3}$ were given respectively as 19 g/kg, 13 g/kg, 337 g/kg, and 182 g/kg. These results puzzle me for the following reasons: 1) Iodine, being a ...
-2
votes
0answers
19 views

Order of acid-carbonate reactions [on hold]

For an assignment I am investigating the reaction $$\ce{MCO3 + 2HCl -> H2O + CO2 + MCl2}$$ where M is a group 2 metal and zinc. I am investigating changes in the rate of reaction and for that I ...
1
vote
2answers
74 views

How to calculate pH of basic salt solution mixed with strong base?

Calculate $\mathrm{ pH }$ of $\pu{ 0.05 mol }$ of $\ce{Zn(CH3COO)2}$ and $\pu{ 0.025 mol }$ of $\ce{ NaOH }$ dissolved in $\pu{ 1 L }$ of distilled water? I tried to use the systematic method by ...

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