0
votes
0answers
5 views

Determining exponets in rate law with different data

Here is the experimental data: Note all concentrations are the initial amounts Experiment$\,\,\,\,\,\,\,\,\,[C_{2}H_{4}Br_{2}]$ $\,\,\,\,\,\,\,\,\,\,\,\,\,[I^-]\,\,\,\,\,\,\,\,\,\,$ Initial rate of ...
1
vote
0answers
8 views

Donation by inductive effect and withdrawal by conjugation

Is there a group that would attached to a benzene ring, donate electrons by inductive effect and withdraw them by conjugation?
2
votes
2answers
51 views

During a phase change in matter, why doesn't the temperature change?

I was working on something in school and came across the question: "Why do you think the temperature does not change much during a phase change?" I'm really not sure why this happens in matter ...
1
vote
1answer
12 views

Bond Angles and intermolecular interactions

It's fun to consider bond angles of molecules in isolation. For example, what is the number of different bond angles exhibited by the most polar form of $\ce{SIBrClF2}$? However, can bond angles ...
1
vote
1answer
15 views

Show proposed mechanism is consistent with the experimental rate law

The mechanism for the reaction: $$NO_{(g)}+O_{2(g)}\xrightleftharpoons[k_{-1}]{k_{1}}NO_{3(g)}\,\,\,\,\,\,\,\,\,\,\,\,\,(fast)$$ $$NO_{3(g)}+NO_{(g)}\xrightarrow{K_{2}} ...
0
votes
1answer
21 views

Calculate $K_{ps}$ from a galvanic cell

Knowing that at 25°C the following galvanic cell: $\\ Pb~|~Pb(NO_3)_2~1M~||~PbS~saturated~|~Pb$ shows an $emf =0,413~V$, find the $K_{ps}$ of $PbS$. My try: This is a concentration cell based on ...
1
vote
0answers
16 views

Separating citric acid from sugar

I'm trying to get as pure citric acid as possible from a mandarin. It's not because I desperately need citric acid, but because I want to achieve this. I started by grating the mandarine and ...
1
vote
0answers
9 views

Enzyme Assay - pectinase

I am working on Enzyme Assay.I assayed the enzyme in different buffers from $pH\ 1-12.5$ However,the enzyme has good activities starting from $pH\ 1-10.5$ Is that possible to have enzyme activity in ...
2
votes
1answer
503 views

Graphene Vs Copper?

I was wondering about the amazing conductive properties of graphene, lets assume a large copper bar that is 10 kg, current of 1kA and probably more can flow in it, what about graphene? It certainly ...
0
votes
1answer
17 views

Calculate the wavelength of electron

Kinetic energy of electron is $1.67 \times 10^{-17}$. Calculate the wavelength ($\lambda$) of electron. I know the formula $\lambda= \frac{h}{mv}$; where h is plank's constant. How to find ...
3
votes
1answer
33 views

Black Smoke Produced from Regular Lighter but Not Torch Lighter Applied to Copper

I have a piece of copper mesh from which I would like to remove all coatings/oils. The copper comes from a pot scrubber like this. In order to remove any residue, I held a standard bic lighter up to ...
8
votes
1answer
38 views

What chemicals are used in receipt paper?

Most "invisible inks" turn brown when heated and they take a while to transform. I would like to make (or obtain) an "ink" that responds to the heat of an iron and permanently turns black or a ...
3
votes
1answer
193 views

What is the exothermic reaction of superglue with cardboard?

I glued a sheet of paper to a cardboard package using superglue. To my surprise the paper became very warm. What kind of reaction is it? (The glue in question is labelled with Ethyl ...
-1
votes
0answers
33 views

Chemical equilibrium coefficients [duplicate]

$$\ce{A + B -> C + D}\\ Keq= \frac{[C][D]}{[A][B]}\\ $$ Now if I write $$\ce{2A + 2B -> 2C + 2D}\\ Keq= \frac{[C]^2 [D]^2}{[A]^2 [B]^2} = Keq^2 $$ How is this possible?
4
votes
3answers
172 views

Boat conformation: axial hydrogens

In my exam, my teacher asked me if the following is true: "The chair cyclohexane has more axial hydrogens" I did not have time to think, so I just put false. And apparently I was right. But, at home, ...
1
vote
1answer
13 views

Electrochemistry concentration problem

If I take the electrodes as nickel and silver, I've according to the nernst equation that $\ce{Ni(s) + 2Ag+(aq) -> Ni^2+(aq) + Ag(s)}$ Now $E=E_{0} - \frac{RT}{2F} ...
4
votes
1answer
36 views

Deamination of Spermidine?

I was making a solution of spermidine, and noticed that Sigma Aldrich warns that spermidine solutions deaminate over time. I tried to think of how that would happen, and made a diagram: Assuming ...
3
votes
1answer
59 views

Distillation: Simple vs Fractional

Here is the excerpt of my lab manual: "Simple distillation is more useful for purifying a liquid that contains either a non-volatile impurity or small amounts of higher or lower boiling impurities. ...
4
votes
0answers
69 views

Scary jelly forming on zinc anodes

I'm continuing with my electrolysis experiments. Over a long time, I seek a perfect electrodes. It seems, that when you pick the right anode and cathode, it might be a lot cheaper than universal ...
-2
votes
0answers
20 views

How do I write the units for this question? [on hold]

The weight of an object is the product of its mass, m, and the acceleration of gravity, g (where g=9.8 m/s^2). If an object’s mass is m=10. kg, what is its weight? Is the answer 9.8 kg*m/s^2 or ...
2
votes
1answer
15 views

Cell Representation of a galvanic cell:

I know basic cell representations of galvanic cells and can identify the anode/cathode. But here's a weird representation that I encountered and couldn't understand it: $\ce{Pt|H{2}(g)}(1.0 ...
2
votes
1answer
62 views

Nitrosation of benzene

How does benzene react with NaNO2/HCl? Will PhNO be obtained? I read that pyridine can be produced under special conditions, but what will happen in some less exotic conditions?
1
vote
1answer
25 views

Homemade filter paper

I used normal paper from my notebook to perform filtration. The filtration is 100% perfect, but takes incredibly long to happen, because the paper is too dense. I'm not planning to buy filtration ...
3
votes
1answer
58 views

Are there any negatively charged electrophiles, or simply neutral and positive?

When reading up on electrophilic aromatic substitution, most resources refer to electrophiles as positively-charged species, "in general" or "mostly". What are non-positively charged electrophiles? ...
0
votes
0answers
7 views

How to get sodium from sodium aluminate?

The sodium aluminate is formed when aluminium or aluminium hydroxide reacts with water solution of lye. After drying the water you'll end up with white crystals - sodium aluminate. I was wondering if ...
0
votes
1answer
21 views

why cant organic acids be concentrated and used as a concentrated acids like conc sulphuric acid etc?

Is it possible to make organic acids concentrated like inorganic acids like conc. sulphuric acid etc?
-4
votes
1answer
42 views

Why do Diet Coke and Mentos react? [on hold]

Why do Diet Coke and Mentos react which causes the rapid formation of foam? It's because of Aspartame and CO2? A Diet Coke bottle, shortly after Mentos were dropped into it:
3
votes
0answers
22 views

How do I round a calculation involving both addition/subtraction and multiplication/division to the correct number of significant figures?

I'm just learning about significant figures (sig figs) in my chemistry class, and I'm confused about the rules. An example to my problem: if I had the following expression: $$\left ( \frac{2.378 - ...
2
votes
1answer
31 views

About the way chemicals and molecules are represented

The standard way of representing molecules with letters like $\ce{C}$ for Carbon, $\ce{O}$ for Oxygen etc.; and a lot of lines and double lines like a graph from Graph theory where each letter is a ...
0
votes
1answer
19 views

Is there way to detect surface area of nanoparticle by electrochemical technique?

I want to know other than SEM is there any other technique or instrument to detect the surface area of particle esp eletrochemical way.
2
votes
0answers
9 views

Dissolving Time Function for Concrete

So I was just exploring some ideas on my own and am having trouble analytically solving the following: Let $D(n,m,T)$ be the time it takes to dissolve an n x n x n cube of concrete in m molar HcL at ...
-1
votes
1answer
23 views

Protonation of nitric acid [on hold]

I found that reaction: HNO3 + 4.1633363423443E-17 H3O = NO2{+} + OH{-} Please help me understand " 4.1633363423443E-17" term.
2
votes
2answers
74 views

Determining if reaction is endothermic or exothermic using equilbrium constant

For the following reaction: $$W_{(s)}+4\,Br_{(g)}\rightleftharpoons WBr_{4(g)}$$ At 900 K, $K_{p}=100$ and at 2800 K, $K_{p}=5$. At higher temperatures, the equilibrium has shifted towards the ...
0
votes
1answer
26 views

Dihedral angle of gaseous and crystalline HOOH

Why does hydrogen peroxide exhibit a dihedral angle of 111.5 degrees in the gaseous state? And a dihedral angle of 90.2 degrees in the crystalline phase? I know that in general, there is likely to ...
1
vote
1answer
13 views

Addition of combined gas law constant

There are two containers connected to each other but separated by a cork. If container(1) has a gas $G_1$ at a volume $V_1$, pressure $P_1$ and temperature $T_1$ and similarly in container(2) there ...
1
vote
1answer
18 views

Home-made way to detect lye in solution

I believe that electrolysis of salt water creates lye ($\ce{NaOH}$ - sodium hydroxide). In salt water, there's $\ce{Na+}$, $\ce{Cl-}$, $\ce{H+}$ and $\ce{OH-}$ as of ionts. So at cathode, you get ...
0
votes
1answer
38 views

Is it possible to make meta-phenol?

Normally phenols have the $\ce{OH}$ group at the 1 or 4 position. Can they be made at 2 or 3 positions, where nitro groups and $\ce{-CN}$ can attach? If not, why not?
2
votes
2answers
24 views

Extracting silver from Tollens test

When we add tollens reagent (diamminesilver(I) cation, $\ce{[Ag(NH3)2]+}$) to glucose it forms a silvery mirror on the walls of the container. Since the sides are coated with actual Silver, is ...
0
votes
1answer
23 views

How to separate HCl and NaOH from an aqueous solution of NaCl?

At home I make experiments on salt (as it is easily available at home). One day I came to know that on mixing salt and water I will get Hydrochloric Acid and Sodium Hydroxide. So I became really ...
0
votes
1answer
17 views

How to sour brown rice [on hold]

How can I get cooked brown rice to sour before molding? I used to make delicious waffles with cooked brown rice that had soured. The rice itself smelled awful, but made wonderfully sweet ...
1
vote
0answers
16 views

Identifying probable compound using its colour & reactants

This is quote from OxyChem document on Hypochlorites: Steel tanks in caustic soda service become passivated with a gray-black film forming on the metal. Thereafter, caustic soda at less than ...
1
vote
0answers
10 views

Does CO2 dissolution in different salt concentrations affects the amount of carbonic acid formed?

We have a school experiment, where I must report on the following question: Does salinity affect the solubility of $\ce{CO2}$ in saltwater? So we selected four different concentrations of salt ...
2
votes
2answers
54 views

Why does alcoholic KOH prefer elimination whereas aqueous KOH prefers substitution?

What is the basic difference between aqueous and alcoholic $\ce{KOH}$? Why does alcoholic $\ce{KOH}$ prefer elimination whereas aqueous $\ce{KOH}$ prefers substitution?
0
votes
1answer
25 views

How does the vacuum in atoms persist?

From very elementary chemistry I understand that atoms are mostly empty space, with a few tiny little objects whizzing around. There must then be a vacuum in between these particles. I always thought ...
1
vote
1answer
20 views

TLC: Why is a more polar eluent more effective at displacing the points?

If the points are non-polar, I don't see how making the eluent more polar will make them travel faster. Anybody care to explain?
3
votes
2answers
61 views

Why are metal oxides generally more stable than their corresponding elemental forms?

Why is the oxidation of certain metals such as iron favorable from a thermodynamic standpoint? What is it about these metal oxides that makes them inherently more thermodynamically stable than their ...
3
votes
1answer
38 views

When it comes to bond energy or molecular binding energy, do people mean enthalpy?

When calculating bond energy or molecular binding energy, which value should I use, enthalpy or total energy? For example, A+B=C Should it be C's enthalpy of formation minus (A's+B's)enthalpies of ...
0
votes
2answers
47 views

Preparation of NaOH Solution

How would one prepare a one molar sodium hydroxide solution? I see a few issues with this: $\ce{NaOH}$ absorbs carbon dioxide. So old NaOH samples might have a significant portion of $\ce{NaHCO3}$ ...
0
votes
2answers
19 views

Can citric acid protonation produce benzene and water

Is this reaction possible: $\ce{C6H8O7 + 12 H3O -> C6H6 + 19 H2O}$? Considering that the $\ce{H+}$ can be induced by ionization of the citric acid solution the benzene can be produced in this way?
3
votes
1answer
40 views

How does KMnO₄ affect electrolysis?

I'm just blindly experimenting. I tried to dissolve some potassium permanganate in water before performing electrolysis. I can't see much difference. How is $\ce{KMnO4}$ dissolved in water? How does ...

15 30 50 per page