0
votes
1answer
10 views

Why does Bismuth only create a +3 ion instead of a +5 ion?

It has 5 valence electrons, but only loses 3 of them to make a +3 ion. Why does this occur? I believe it may have something to do with how losing 3 electrons leaves you with the p sublevel full, but ...
0
votes
1answer
14 views

“Ate” complexes

I understand that ate complexes can result from the addition of carbanions to neutral aluminum alkyls. I was wondering what the balanced equation for this reaction is/what the structure would be in ...
0
votes
0answers
8 views

Electron count and oxidation state

I was wondering what the d-electron count of the transition + formal oxidation state of [C4H7-PdCl]2 is! Thanks!
0
votes
0answers
11 views

Explain why the acidification of solution can lead to separation of ions such as Fe2+ and Zn2+ from aq solution

Given the $K_{sp}(\ce{ZnS})= 2.5\cdot10^{-22}$ and the $K_{sp}(\ce{FeS})= 3.7\cdot10^{-19}$, why would $\ce{Fe^{2+}}$ ions remain in the solution but not $\ce{Zn^{2+}}$ with the acidification of the ...
0
votes
1answer
11 views

Controlling the shape of metal

Is there a way to control the shape of metal? Suppose I have a fast melting metal, is there a way to make it take a specific shape? Of course I don't mean to like put it in a template to take the ...
0
votes
3answers
26 views

A metal that melts quickly?

Is there a kind of metal that melts very quickly with very low heat or temperature and at the same time becomes hard very quickly? I'm very naive in chemistry with limited knowledge. So I hope your ...
2
votes
1answer
29 views

What are some good research topics for a high school student?

I absolutely love chemistry and I really want to take part in science fairs. I am also taking an AP chemistry class. Cleaner fuel and energy sources and air pollution (especially due to smog and ...
1
vote
2answers
37 views

Product of Reaction?

What would be 'A' in the reaction (see image)? Any help would be deeply appreciated. I know that Alc KOH does elimination but I was confused whether it would eliminate one bromine each from two ...
3
votes
2answers
99 views

Why are high pressures used in cracking of long-chain hydrocarbons?

If we have a long-chain hydrocarbon, such as decane, and we split it through thermal cracking (say in an industrial plant), we use high temperatures, and high pressures. Cracking produces smaller ...
0
votes
1answer
10 views

What kind of equilibrium constant we use for Gibbs free energy and Van't Hoff equation?

We know that Gibbs free energy is same as negative of 8.314 times temperature in Kelvin times natural logarithm of equilibrium constant, or: Then, we also know Van't Hoff equation, like: (R in ...
1
vote
1answer
18 views

Why is adiabatic process isentropic?

I have read that adiabatic process is isentropic because there is no heat exchange in an adiabatic process and thus no change in entropy. But my question is - Even in adiabatic process, work can be ...
1
vote
2answers
21 views

Could someone please explain the difference between m/z and m/e in mass spectroscopy

The definition: The abbreviation m/z is used to denote the dimensionless quantity formed by dividing the mass number of an ion by its charge number. It has long been called the mass-to-charge ratio ...
0
votes
0answers
24 views

Calculation of Equilibrium Constant

How do You solve this? $$\ce{2SO2 + O2 -> 2SO3}$$ Starting with $1$ mol of $\ce{SO2}$ and $1$ mol of $\ce{O2}$ in a 1 litre flask, the equilibrium mixture required $0.4$ mol $\ce{MnO4^-}$ in ...
0
votes
2answers
19 views

Examples of electronically conductive foods?

There are many foodstuffs that are ionically conductive (for example, anything moist and salty). What about foods that have a high electronic conductivity? The only thing I can think of would be ...
0
votes
1answer
27 views

How to identify a substance acting as an acid

For question ii, it asks to state a reaction showing $\ce{H2SO4}$ acid acting as an acid. What does it mean acting as an acid? Donating a proton? Very confused as to what to look for. The answer ...
1
vote
3answers
37 views

Formula for hypo

Can someone please tell me the chemical formula for just "Hypo"? This question came up in previous exams and I don't know what is the general /chemical formula for just "Hypo". I can find the formula ...
1
vote
0answers
17 views

To model early fluid flow which types of pumps should be used?

I have I microchannel test rig , I want to push a 150-300 ml/hr from water in my test , I would like to know which pump type i can use ?
0
votes
0answers
16 views

Spectrochemical Series - Sigma Donor Capability

I fully understand and recognise the manner and which the series works. I cannot find any references for the change in sigma donor capability moving up the series. For example, comparing Cl- and ...
0
votes
1answer
22 views

Laws of Chemical Combination

I'm doing revision questions and want to double check something. The opening information reads: Two chlorides of iron were prepared. One was prepared by reacting iron with dry chlorine gas. 4.50 g ...
2
votes
1answer
39 views

Animate molecular vibrations as multiple xyz coordinate files

I have a frequency calculation by Gaussian09. Now I would like to extract vibrational modes as a set of xyz coordinate files. I would like to manually recompute numerically the points along a ...
0
votes
2answers
35 views

Chemical Equation: Sulfuric acid and powdered sodium carbonate

Asked to write a balanced chemical equation for the reaction between sulfuric acid and sodium carbonate. The balanced equation isn't the problem. The question asks to also show all the state symbols. ...
0
votes
0answers
26 views

A 200g sample of aluminum loses 500 calories [on hold]

A 200g sample of aluminum loses 500 calories. If it starts out at 120 degrees C, find its final temperature (C = .21 cal/gdegreeC)
2
votes
1answer
28 views

Why there exist no void with co-ordination number 5

Here oh = octahedral td = tetrahedral CN = co-ordination number My problem is that, that why it is not possible to have a void with CN ...
0
votes
1answer
34 views

Degenerated Orbitals

How do I find if an atom has degenerated orbitals? My Understanding I understand that degenerated orbitals mean orbitals that have the same energy level for the same n. However, how do I distinguish ...
0
votes
0answers
37 views

Michael addition reaction question [on hold]

Under basic conditions, a michael addition reaction can be used to convert compound A into compound B. Show mechanism and reagents used. Explain why no Robinson annelation reaction can occur. ...
0
votes
0answers
27 views

Cross Claisen Condensation question [on hold]

The cross claisen condensation of ketone A with compound B creates a 1,3-dicarbonyl compound C. Draw the mechanism for the reaction. State what property of compound B makes it ideal for this type of ...
0
votes
1answer
28 views

Malonic ester synthesis question [on hold]

How can the malonic ester synthesis be used to prepare carboxylic acid A from the starting material B? Show mechanism and reagents used. Carboxylic Acid A Starting Material B
1
vote
1answer
40 views

Bonding, multiplicity and quantum chemistry for FeP$_2$

I'm trying to do some quantum chemical calculations for the linear molecule FeP$_2$ in the gas phase as well as its crystal (orthorhombic symmetry like here). I am lead to believe that in both cases ...
0
votes
1answer
26 views

Empirical and Molecular formula: Homework

I'm working on a high school chemistry book and want to double check one of the homework assignments. The question is for students to write the empirical and molecular formula for 1,2-dichloroethane. ...
0
votes
2answers
45 views

HF and water miscible?

According to Wikipedia, HF is miscible with water. But isn't hydrogen fluoride a gas at RT and a sensible pressure? What would happen if you just kept adding more HF gas to some water?
0
votes
1answer
22 views

Difference between an absorbance, emission, and excitation spectrum for uv-visible spectroscopy

The exam paper answer is 500, because we need the wavelength of "maximum absorbance." But this graph shows two curves, and the absorbance curve is omitted. But what is the difference between an ...
0
votes
1answer
45 views

Preparation of a benzoate buffer [on hold]

What mass of sodium benzoate should be added to 140.0mL of a 0.17M benzoic acid solution in order to obtain a buffer with a pH of 4.25? To find mass you need mols i believe and to find mols you need ...
0
votes
3answers
29 views

pH and materials selction

I working on the Navy study guide for their nuclear engineering programs and I am not a Chemist. Thus, I have come here to try and develop a better understanding of the subject matter. I am trying ...
1
vote
2answers
65 views

Given the volumes: determine the pH and the final temperature of a mixture knowing only the initial pH and the temperature of the un-mixed components

I have a pretty basic question but the last time I took Chemistry was in 2007. I am studying the Navy's Nuclear study guide for their interviews and one of the question I am faced with is below. ...
0
votes
0answers
24 views

How to determine mineral properties based on chemical formula?

I need to learn a bunch of minerals and their properties. What I want is some sort of rule which helps me deduce color, crystal system, luster etc. I know that different kind of ions give specific ...
2
votes
1answer
52 views

Instantly seperate oil and water

I have a solution of water and oil mixed to as much as possible, since they won't actually mix. The supply is coming down a pipe at a relatively fast rate and I need to separate it so that the water ...
0
votes
1answer
37 views

endothermic dissolution process

Can anybody give me an example of an endothermic dissolution process, preferably one in which name of the substances involved are easy to remember. I have searched the Web thoroughly but could not ...
0
votes
2answers
21 views

How to determine source of air pollution

It should be determined by some metal markers (meaning originating from traffic etc.) but I cannot find any source which would describe it. Thanks.
0
votes
1answer
20 views

How is Humic substance destroyed in nature?

Humic substance consists of many, to my knowledge poorly understood, species of organic matter, mostly carbohydrates chained in intersting (and also poorly understood) ways. Humic substance is an ...
0
votes
0answers
64 views

What was the misconception about the search of Philosopher's Stone and how does modern chemistry deals with this topic? [on hold]

I just read about Alchemy. And it seems to me that many of their principles are closely related to chemistry. So, here is my doubt - Why is not possible to make that alchemist stone called ...
0
votes
1answer
15 views

Calculating molar conductance?

Ok, so the following question is given in my text book. Of the molar conductance value of $Ca^{2+}$ and $Cl^-$ at infinite dilution are respectively $118.88\times10^{-4}$ and $77.33\times10^{-4}$ ...
0
votes
0answers
27 views

How to calculate m/e value for the base peak in mass spectroscopy?

My working out: Propan-1-ol : CH3CH2CH2OH This can be broken up into: CH3 + CH2CH2OH CH3CH2 + CH2OH CH3CH2CH2 + OH Base peak = most abundant fragment formed (highest peak) How do i know which ...
0
votes
1answer
18 views

Calculate accelerating voltage required to separate two particles in a magnetic sector analyser

So, in mass spectrometry we have the following equation to describe a magnetic sector analyser, $$\frac{m}{z}=\frac{B^2r^2e}{2V}.$$ Lets say that I have two particles with different mass/charge ...
0
votes
1answer
14 views

Thermochemistry Delta T?

An equation of heat is s * m * delta T. I know that delta T can be in either Celsius or Kelvin. However, one thing that confuses me is how the units cancel if delta T is in Celsius. How does this ...
0
votes
0answers
11 views

Does Bioglass 45S5 attach to enamel?

When I search, I see bioglass binds to bone and dentin, but nothing is said about enamel. The bioglass allows the creation of a hydroxyapatite, and from what I've read I think enamel is ...
0
votes
0answers
37 views

what is the compound structure for the following IR & NMR data [on hold]

Please some one help me solving this problem it is very difficult for me it is about spectroscopy, i couldn't solve it here is the question what is the compound structure for this IR& NMR data ...
0
votes
1answer
33 views

Zinc Picolinate - Positive, negative or neutral charge?

I'm going to be using a finings agent with a positive charge to remove negative trub from a solution (beer). I would like to keep some chelated zinc in the solution - ideally zinc picolinate - so ...
1
vote
1answer
20 views

Change in pressure or volume of molten salt

I am doing a project in which I fill a cylinder with a volume of $636cm^2$ (made of stainless steel) with molten salt: 60% Sodium Nitrate ($NaNO_3$) and 40% Potassium Nitrate($KNO_3$). The container ...
0
votes
1answer
23 views

UV-Visible Spectroscopy in the analysis of sodium chloride in potato chips

Here is the question and answer out of an exam paper: Firstly, I thought UV-Visible can also use radiation in the visible spectrum. Also when analyzing sodium chloride (a molecule), then UV-Visible ...
0
votes
2answers
36 views

1H-NMR and deducing structures

here is the data booklet we must refer too: Here is the exam paper solution: I dont understand how they conclude this. Peak areas and the chemical shifts seem to be different for me. For ...

15 30 50 per page