# All Questions

28,675 questions
37 views

### Do endothermic reactions have a higher absolute change in temperature than exothermic reactions? [on hold]

or does it depend on the reaction itself. I am conducting an experiment and the endothermic reactions have temperature changes of at least 8 degrees while the exothermic reactions have a change in 1 ...
31 views

### How many moles of methyl iodide will be consumed by one mole of crixivan?

My take on this question : a total of 5 moles of $\ce{CH3I}$ should be consumed. The oxygen atoms in the $\ce{2 OH}$ groups each have a lone pair of electrons. They should displace $\ce{I-}$ from ...
33 views

### What is the point of POAC? Why can't one just balance?

I have been studying the principle of atomic conservation, but have not understood why it even exists. For example: What mass of $\ce{O2}$ is produced by 1.23 g of $\ce{KClO3}$? Couldn't this ...
24 views

### Zinc and copper [on hold]

Is potential energy and ionisation energy are same? Plz explain with respect to zinc Why zinc is undergoing oxidation when combined with with zinc. copper in electrochemical series
17 views

### E. coli biochemistry ? question or organic chemistry question [on hold]

If there is E. Coli in manure. And heating up E coli will kill it off. Would boiling/heating fresh manure kill any E. Coli permanently making it safer for a fertilizer. Or would it return and thrive.
18 views

### Br2/ch3cooh vs Br2/ccl4 [on hold]

Is the work of Br2/ccl4 and Br2/ch3cooh same(i.e anti addition of bromine to double bond)? If not, then please provide an example also..
43 views

### Perpetuum mobile using electrolysis [on hold]

I'm trying to better understand electro-chemistry, so please explain why this second-kind perpetual motion device won't work. I guess it's safe to assume it won't work one way or another. There is a ...
18 views

### Chemical bonding if an atom or molecules [on hold]

Describe the covalent bonding electron arrangement in the following by atomic molecules: 1, fluorine , 2,oxygen and 3, Nitrogen
16 views

### Chem KC expression [on hold]

Sulphur dioxide gas reacts with oxygen gas to give sulphur trioxide, balance the equation and select the correct Kc expression for the reaction. SO2 (g) + O2 (g) ↔ SO3 (g)
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### PCl3 Molecular Orbital Diagram [on hold]

I'm having trouble constructing the molecular orbital diagram of the PCl3 molecule. I'm supposed to use symmetry arguments and group theory (instead of hybridization), and consider the influence of ...
19 views

### what is the crystal compound formula for the ratio of elements 1:2 [on hold]

How do you find the crystal compound formula when the ratio is given. for example, if you have the ratio of compound 1:2, what will be the formula of compound be?
22 views

### Use of the reagent: Br2 + ch3cooh in the given question [on hold]

(https://i.stack.imgur.com/JEzGs.jpg) Do the products formed by Br2/Ccl4 and Br2/ch3cooh same?
34 views

### Reaction of diacetyl with acid

What happens when diacetyl, that is, butan-2,3-dione is treated with acid? I guess there would be acid catalysed aldol formation. But what would the final product be? I can see too many ...
35 views

### Can 6M HCl precipitate NaCl out of a solution? [on hold]

I want to do an experiment that precipitates NaCl by using HCl and the common ion effect. Will I can't use 12M HCl. Can it be done with 6M HCl https://melscience.com/en/articles/salting-out-experiment/...
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### Carbonation of Grignard reagent with a carbonyl group present in it

Here's the question in my book (see picture) Option A is a standard reaction which gives a carboxylic acid. Option B is definitely wrong because an acid base reaction will take place and CH4 will be ...
153 views

### Gibbs free energy in standard state vs. equilibrium

I have a problem with the definition of the standard Gibbs energy and its connection to the equilibrium constants. I think, that I've basically understood what the different equation mean but there ...
25 views

### Basic strength of the compound with an conjugate, and an aromatic amine

According to the source of the question answer is c>a>b but shouldn't the order be c>b>a as (a) is attached to a benzene ring and the lone pair will be delocalized?
15 views

### Creating simulations online to get a better intutive ideas about abstract topics in chemistry [on hold]

As a Lecturer in Chemistry, I have used ready made simulations for students by https://phet.colorado.edu/en/simulations/category/chemistry where it deals with performing some online experiments to get ...
17 views

### When burning Metal Salts such as Lithium Chloride is the emission toxic? [on hold]

I'm completely new; Just thought this was the place to ask.
13 views

### 6,6-dimethyl-5-hydroxy-4-oxo-3-phenylpyrrolidino-[1,2-b]pyrazole structure [on hold]

The exact question was "structure of product of Wolff-Kishner reduction of 6,6-dimethyl-5-hydroxy-4-oxo-3-phenylpyrrolidino-[1,2-b]pyrazole". Wolff-Kishner reduction should be easy enough to ...
31 views

### Conversion of graphite into diamond [duplicate]

The standard state Gibbs free energies of formation of C(graphite) and C(diamond) at $T = \pu{298 K}$ are $\pu{0 kJ mol-1}$ and $\pu{2.9 kJ mol-1}$, respectively. The conversion of graphite [C(...
20 views

### making POTASSIUM SULFATE less harmful [on hold]

I was just wondering (since my chemistry is really bad)if potassium sulfate (produced from potassium . hydroxide and sulfuric acid to get potassium sulfate and water) can be made less hazardous by ...
19 views

### As a chemistry major, do you end up memorizing a bunch of biochemical signalling pathways instead of verifying them? [on hold]

I am curious to know if biochemistry majors learn these signalling pathways from a book over doing an experiment to verify what is being taught.
21 views

### Flame Ionization Detector versus Mass Spectrometer

Why is chromatographic separation more important with a flame ionization detector than with a mass spectrometer?
28 views

### Why do we use thermal decomposition of ammonium beryllium fluoride to produce beryllium fluoride?

Why do we use thermal decomposition of (NH4)2BeF4 to produce BeF2 rather than use BeO and HF? In my textbook it is written that the thermal decomposition route is more convenient than reaction of its ...
16 views

### How do you “test” the Citric Acid Cycle and see all of the intermediates produced as predicted? [on hold]

Could anyone give me an experiment where I can test the Citric Acid Cycle?
10 views

### What substance added to liquids that creates pressure and sours liquid? [on hold]

Some substance added to my green tea and 64 oz. Bottles of v8 tomato juice (liquids) that creates pressure and sours liquid in a matter of hours....
17 views

### Treatment of ambidentate ligands in geometrical and optical isomerism

Are ambidentate ligands considered different entities when they donate through different atoms? For example will a hypothetical square planar complex like [Pt(ONO)2(NO2)2] show geometrical isomerism?
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### Arrange the following in increasing order of contribution to resonance hybrid [on hold]

Arrange the following in the increasing order of their stability  \underset{\text{(I)}}{\ce{CH2=\overset{+}{N}=\overset{-}{N}}} \quad \underset{\text{(II)}}{\ce{\overset{+}{C}H2-N=\overset{-}{...
15 views

### chemical equation [on hold]

A butyl rubber bag of total volume 3.0 m3 is used as a biogas digester. Each day it is fed an input of 0.20 m3 of slurry, of which4.0 kg is volatile solids, and a corresponding volume of digested ...
16 views

### Help me with the mechanism .I tried much..but could not do it [on hold]

I can’t understand After epoxied ring opening how they cyclise ,
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### Help with my lab please! [on hold]

For my lab, I am changing the concentration of 1-hexene and hydrogenating it. The issue is, I was going to find rate of reaction, but I don't know how to monitor the time, so i don't think finding the ...
41 views

### Is NaCl the only precipitate when you add HCl to concentrated NaCl [on hold]

When aqueous HCl is added to a saturated salt water solution, is NaCl the only precipitate or does some HCl crystalize as well? Sources online say that NaCl crystallizes but they don't say what ...
300 views

### Why are synthetic pH indicators used over natural indicators?

Synthetic indicators seem to be exclusively used when determining the pH of a substance with an indicator (with the exception of that school experiment where you boil cabbage to demonstrate natural pH ...
483 views

### Is there a name for this algorithm to calculate the concentration of a mixture of two solutions containing the same solute?

There is an algorithm called "Mischungskreuz" (German for "x of mixing") that is sometimes taught as a shortcut to figure out the following problem: You have two solutions that contain a solute at ...
20 views

### How do I make 100 milliliters of 100mM H2O2 using 3% H2O2? [on hold]

I need to make 100 milliliters of 100mM H2O2 using 3% H2O2. Do I: add X milliliters of distilled water to the 3% H2O2? How many ml? or add X milliliters of 3% H2O2 to the distilled water? How ...
88 views

### Is there a error at page 566 of Atkins Physical Chemistry? [on hold]

At page 556 I found this question being analyzed and the rate law is provided. However, when I apply steady state approximation, I can't find the result without the factor 2. Is it me being wrong?
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### What factors affect energy density of a combustible fuel? [on hold]

Define energy density of a combustible fuel as the energy released per unit volume of the fuel. I know that intermolecular force strength as well as steric effects (entanglement) are factors that ...
46 views

### Using Roman Numerals to indicate a compound

I don't completely understand it's use. Here's an example I don't understand: Shortly after discussing $\ce{[CuCl4]^2-}$, an exam paper asked a question about copper(II) chloride. I understand that ...
20 views

### solution 3 results from combining solution 1 with soultion 2. Just need a formula or equation [on hold]

solution 3 results from combining solution 1 with soultion 2. solution 1 consists of 2ml of cells at a concentration of 5x10^6cells/ml. solution 2 consists of 7.0ml of cells concentrated at 3x10^6 ...
19 views

### How to make auto zero in calibration graph during graph plotting? [on hold]

I am using Origin 9.1 software for graph plotting. I have collected data from Ion Chromatography Instrument. Peak area vs conc. It should be y = mx type of graph Fitted graph shows in few cases ...
25 views

### In Ion Chromatography instrument, Does the specific conductivity (peak area) of an analyte depends upon background conductivity?

In Ion Chromatography instrument, Does the specific conductivity (peak area) of an analyte depends upon background conductivity ? Assume Specific Conductivity (peak area) of fluoride ion is 4 unit ...
20 views

### A hydrated transition metal ion is colourless. Which of the following could be the electronic configuration of this ion?

Here are the options: A [Ar] 3d$^{5}$ 4s$^{2}$ B [Ar] 3d$^{8}$ C [Ar] 3d$^{10}$ 4s$^{2}$ D [Ar] 3d$^{10}$ I would have thought B, as it has an incomplete d-subshell, and it doesn't have any 4s ...
7 views

### a 100 ul stock solution of DNA is at 167 ug/ml. to what volume should you dilute the stock to achieve a working concentration of 40ng/ul [on hold]

a 100 ul stock solution of DNA is at 167 ug/ml. to what volume should you dilute the stock to achieve a working concentration of 40ng/ul
11 views

### Why NCl3 and PCl3 gives different product on hydrolysis? [duplicate]

My answer: N and Cl form non polar bond due to similar electronegativity. N doesn't have empty d orbital so hydrolysis takes place with donation of lone pair of N to H-atom of water. PCl3 forms polar ...
17 views

### How to recreate bioluminescence in fireflies in a lab?

I have several mg/mL of D-luciferin, luciferase (firefly), ATP solution (25 mmol) and MgSO4 (for the mg2+ ions). The experiment has to be done in cuvettes of 2,5 mL (if I get any results, it will be ...
17 views

### Why copper has special electronic configuration [on hold]

Cu configuration is different. How can chemists decided its configuration.
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### Which of the 2 structures is more stable?

As far as I know, alkenes with more number of hyperconjugating structures are more stable. Hyperconjugation has a greater stablizing effect than Inductive effect. So, (d) should be more stable as it ...