# All Questions

29,056 questions
18 views

### Using Wilkinson's Catalyst to reduce esters?

I was solving some questions on alcohols when I came upon a question in which it was asked that whether esters can be reduced using hydrogen in the prescence of wilkinson's catalyst. Now I know that ...
138 views

### LDA and an aldehyde

Compounds A and B both react with LDA (lithium diisopropylamide, a strong base) to form the same anion C with the formula $\ce{C4H5O^-Li^+}$. I am unfamiliar with LDA. My first thought was that ...
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### Using Hess's Law [closed]

Calculate ΔH for the reaction 2 Al (s) + 3 Cl2 (g) → 2 AlCl3 (s), given: a. 2 Al (s) + 6 HCl (aq) → 2 AlCl3 (aq) + 3 H2 (g) ΔH = -100.8. kJ b. HCl (g) → HCl (aq) ΔH = -69.7 kJ c. H2 (g) + Cl2 (g) → ...
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### Theoretical Resistance Relationship of Electrolytes [closed]

I'm a senior physics/chemistry student working on a practical assignment where I am trying to identify the resistance of CuSO4 in solution (distilled water). I have recorded my data and determined it ...
34 views

### Which of the following are correct about cycloalkane stability? [closed]

Which of the following are correct about cycloalkane stability? A) Stability ∝1 anglestrain B) Stability ∝1d where d is distortion or deviation from 109°5' for 1 bond C) Stability ∝1 ...
15 views

### Does electron affinity affect bonding [on hold]

I know the Enthalpy for the first electron affinity will be negative, but what happens when an atom bonds with two other atoms and gains two or more electrons? What happens then?
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### Lewis structure of benzenediazonium [closed]

In the benzenediazonium $\ce{C6H5N2+}$ the nitrogen contributes its lone pair to the carbon in benzene. So where is one electron of that carbon, since it is not used for bonding with nitrogen where ...
67 views

### Gibbs Free Energy and Maximum Work

I am a high school student and my professor mentioned that the Gibbs free energy is the maximum amount of work (or useful work) that a system can do, whereas entropy is a measure of the non-available ...
23 views

### Product of 2,4-Pentanedione and PFBHA Reaction [closed]

I have made a solution derivatizing 2,3-Pentanedione with PFBHA. I am trying to figure out the product I have made. I know the chemical formula is C5H8O2 for 2,3-pentanedione and C8H4F5NO for the ...
6k views

### When a candle burns, why does the top of wick glow if bottom of flame is hottest?

Totally an elementary question. Staring at a candle, it appears that the bottom of the wick is dark whereas the top glows. However the bottom of the flame (the blue) is the hottest. Is the reason ...
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### Effect of Concentration on Reaction Rate - Calculating Final Concentrations in Solution [closed]

Question asks: Determine the final concentration of IO₃⁻ used in the reaction. Show a complete sample calculation for the (8.0 mL Solution A + 2.0 mL H2O Equation: IO3− + 3HSO3− → I− + 3 HSO4− ...
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### Ingredient mixing [closed]

what ingredient (when mixed with liquid i.e juice etc...) will help to preserve candy (gummy and hard)? It also has to be non toxic because it is being ingested. It also has to go along with syrups.
52 views

### Why do metals form cations?

metals that have a low number of occupied shells such as lithium and potassium should have a stronger electrostatic attraction to their nuclei, so what causes them to always lose their electrons ...
27 views

### Reactions to Caffeine [closed]

I am looking to see what reacts with caffeine for a school project. I wish to not go too far into detail, seeing that I am trying to invent something to better medicine with, but any information would ...
23 views

### Calculating Volume of CO2 produced [closed]

The question states "What volume of CO2 will be produced if you react 1.5 g of Li2CO3 with an excess of 6.0 M HCl at room temperature?" Which fundamental equations could be used to solve such a ...
40 views

### CIP Rules - How to deal with a double bonded nitrogen? [on hold]

If a substituent were to exist, how will one deal with the doubly bonded nitrogen? In the tree will the nitrogen with the double bond have (C,C) or (C,C,C) or (C,C,lone pair)? I could not find this ...
45 views

### Size of hydrocarbons and boiling point

Increasing the contract surface area between hydrocarbons raises boiling point, so hexane should have a higher boiling point than propane. This doesn't really make sense to me. What is the difference ...
26 views

### What effect do Bond angles have on molecules? [closed]

What are examples of the effect of different types of bond angles between different molecules and between same molecules with different Bond angles?
69 views

### Importance of substrate stereo chemistry in semi pinacol rearrangement [closed]

Consider the following two reactions (source): I don't quite get why the products shown are the main ones. In reaction 3A., if you rotate the carbon facing us by 120 degrees clockwise, the anisole ...
18 views

### Final product when sp2 oxygen of acid is O18 in fischer esterification

In the question above, i was curious about option 3. If the carbonyl oxygen is O18, shouldn't half of the product we obtain contain O18 on the carbonyl since we have two possible leaving groups with ...
258 views

### Why is my conclusion inconsistent with the van't Hoff equation?

Let's say I hypothesize that a graph of $\ln K$ vs. $1/T$ has a slope of $-∆G^\circ/R$ and a $y$-intercept of $0$. I prove it simply: $$∆G^\circ = -RT\ln K \quad\to\quad \ln K = -\frac{∆G^\circ}{RT}$$...
19 views

### Hydrogen peroxide and carbon as hybrid rocket propellant?

I was thinking that a hybrid rocket could be made using hydrogen peroxide and activated charcoal or some other carbon source. Step 1: Decompose hydrogen peroxide to steam and oxygen, as in a ...
26 views

### Could there be a class of drugs beyond, similar to barbiturates and benzodiazepines? [closed]

I'm talking about group of drugs similar to them but different though.Is there anything beyond benzodiazepines?
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### Basicity of subsituted amines

In comparing hydroxylamine, hydrazine, and methylamine for basicity, the order of increasing basicity is hydroxylamine < hydrazine < methylamine. I tried to reason this trend based on electron ...
55 views

### What happens in this reaction! Some hints needed

I understand step A involves reductive ozonolysis. and that step B is addition involves addition of ammonia to the carbonyl site to form imines. But what does the sodium salt of trichloroacetic acid ...
14 views

### Is the exchange interaction always less in value than coulomb interaction? (Absolute values of both.)

I wonder for 2 electron interactions whether exchange interaction (K) is always less than the coulomb interaction(J) value in all cases (HF or DFT) or there is no such necessity? Does it depend on the ...
24 views

### Why can't a thermosetting plastic be stretched like an elastomer?

So far I've learnt that there are 2 'types' of thermosets: thermosetting plastics and thermosetting elastomers. Both of them consists of crosslinks that when stretched, allows for the material to ...
20 views

### Neighbouring Group Participation [closed]

Usually in organic chemistry i have learnt that the more stable the intermediate, the faster the product formation. But in neighbouring group participation don't we get three or four membered rings ...
25 views

### notation on MO diagrams

I wanted to ask a question about notations on MO diagrams. Our first lesson about MO diagrams was today and I was taken through an example with $\ce{F2}$ as shown below: but one thing that the ...
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### Why do tetrahedral organic molecules show stereo-isomerism, but not tetrahedral transition metal complexes?

Both types of molecules show different arrangements of the molecule in space, so they should qualify for optical isomerism right?
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### Why do some ions form tetrahedral complexes more readily than others? [closed]

Why does Co$^{2+}$ readily form tetrahedral complexes such as [CoCl$_4$]$^{2-}$, whereas Fe$^{2+}$ usually forms octahedral complexes?
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### Will evaporation from two immiscible liquids blow up a balloon?

Consider the following setup: Two immiscible liquids A and B are placed inside a balloon at a temperature where neither one of them boils. The inside of the balloon contains some argon, and the ...
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### Does this ring expand in this situation? What's the mechanism behind this? [closed]

So this is picture that sketches the situation. [EDIT] Thanks @glucose for putting me back on the rails. To wrap this all up and complete this topic, the answer to my question should be the product ...
38 views

### Disproportionation of Au(II)

Cu(II) and Ag(II) complexes are known to exist while Au(II) is unstable and disproportionates to Au(I) and Au(III). My guess as a possible reasons to this effect is that Au(II) like Cu(II) and Ag(II) ...
79 views

### Why is reduction potential of water ( 2H₂O + 2e⁻ → H₂ + 2OH⁻ ) is -0.83 insted of 0, as in the case of (2H⁺ → H₂)?

I came across this value of reduction potential of water while solving a question. Also, I noticed that, for example $$\ce{Ag+ → Ag}$$ has a fixed standard potential, and the same is used when we do ...
25 views

### Diluting a sample of weak base before titration. What happens to equivalence point pH of diluted vs undiluted?

A student titrated a 10.00 mL of 0.20 M methylamine ($\ce{CH3NH2}$) and determined that 10.00 mL of $\ce{HCl}$ was needed to reach the equivalence point. If you diluted your original sample of ...
35 views

### IUPAC Recommendations for Concentration Units (ppb, ppm)

In a recent interesting post, (Is 1 ppb equal to 1 μg/kg?) it was pointed out that IUPAC advises to abandon parts per million, parts per billion quantities and instead it suggests to employ micromole/ ...
160 views

### Cp vs Cv for liquid water @ < 4 °C

I'm looking at a textbook question (Engel & Reid, Thermodynamics, Statistical Thermodynamics & Kinetics, 4 ed, Q3.1) which states the following: The heat capacity $C_{\mathrm m,p}$ is less ...
36 views

### Borane as a reducing agent

I understand that adding borane to an alkene will produce a hydroborane. Addition of -OOH will form an alcohol. My lecture notes state that addition of borane to: A carboxylic acid will form an ...
60 views

### Is it safe to boil carbonated water in a kettle? [closed]

Isn't it dangerous to boil carbonated water in a kettle? Whenever I boil water in my kettle, I close its lid. Does this close lid constitute 'under pressure' (and so danger) emboldened beneath? ...
3k views

### Storing hydrofluoric acid before the invention of plastics

The first person to synthesize hydrofluoric acid in large quantities was Carl Wilhelm Scheele in 1771. This acid is known for its ability to corrode glass and metals. What materials were the ...
24 views

### Formula Issue: At what relative concentrations of Pb2+ and Cd2+ will these half-reactions have the same reduction potential 25 degrees Celcius? [closed]

Standard reduction potentials for the Pb2+/Pb and Cd2+/Cd half-reactions are −0.13V and −0.40V, respectively. This is the question, I’m just confused on which formula should be used. E=E^0-(0.0592V/n) ...
34 views

### Calorimetry: Temperature Increase due to stirring of reactants

I am not yet in university, but I hear a common first-year chemistry lab/practical is to do calorimetry taking into consideration the small (and usually negligible) rise in temperature due to the ...
85 views

### Would burning of around 200 kg of animal fat in a tunnel cause an explosion? [closed]

As shown in the movie Ironclad, they burnt a group of fat pigs together, under a tunnel, beneath the fort base and it resulted in a massive explosion. From chemistry's perspective, and considering ...
19 views

### Precipitation of Cu2+ and Pb2+ ions

Hi chemistry enthusiasts! I am working on my scholarship exam practice. I believe this exam assumes high school + first year university knowledge although the standard may be varied across the world. ...
17 views

### Interaction in capsule between resveratrol, berberine, nicotinamide, astaxanthin? [closed]

I would like to know whether mixing Trans-Resveratrol 98%/C14H12O, Berberine HCL (hydrochloride)/C20H19ClNO4, Nicotinamide (vitamin B3)/C6H6N2O, and Astaxanthin/C40H52O4 in a capsule without any ...
32 views

### Change in Gibbs free energy vs. change in enthalpy

When learning about other thermodynamic quantities, like $\Delta H$, I was taught that this represents the energy absorbed or released by a system after the reaction has gone 100% to completion. For ...
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### How fast is the interconversion triplet → singlet in organic molecules?

When computational studies are performed on transition state geometries, the "thermodynamic" (that is, with no kinetic considerations) energy of the analyzed state is obtained. I was wondering: if a (...
Consider a $\pu{10.0 mL}$ solution containing $\pu{1.0e-10 M}$ each of $\ce{Ba(CN)2}$ and $\ce{BaI2}$. If $\pu{3.5e-9 mol}$ of $\ce{AgNO3(s)}$ is added to this solution, will any precipitate(s) form? ...