0
votes
0answers
7 views

How would you find the mass in grams, if you only know the number of particles of a portion of the formula?

If you were given a question like below: What is the mass in grams of a sample of Fe$_2$(SO$_4$)$_3$ that contains 3.59 × 10$^{23}$ sulfate ions, SO$_4^{2−}$ ? The molar mass of ...
1
vote
0answers
8 views

What's the difference between a nucleophile and a base?

Obviously it depends on the context whether you would call a particular species a nucleophile or a base but are the two terms largely synonymous or is there a difference?
1
vote
0answers
10 views

7,7-dichlorobicyclo[4.1.0]heptane NMR solving

i made a synthesis of this material in the lab and now i got the H-NMR specta , and by litreture i know that i got the right product. im having trouble to match the hydrogens to the peaks,i tried to ...
0
votes
1answer
13 views

Good book for foundational chemistry

I need a good book that explains the basics of chemistry in a lucid and importantly, systematic manner. Most books on this subject are not comprehensive and assume that the reader is well acquainted ...
4
votes
1answer
26 views

Does inversion of configuration necessitate reversed optical rotation?

Say, optically pure 2-bromobutane undergoes Sn2 reaction with an alkali to form 2-butanol. The configuration about chiral carbon will now be inverted, but is it necessary that the sign of optical ...
1
vote
1answer
19 views

Procedures in Experimental chemistry

An experiment was carried out involving α-Bromoheptaldehyde dimethyl acetal. The experimental details are given below. A solution of enol acetate (15.6 g, 17.7 mL) in chloroform (20 mL) was cooled ...
1
vote
1answer
13 views

Is there a material that reduces copper melting point and completely dissolves?

Is there any material that you mix/alloy with copper that will result in something that behaves similar to plastic (that is at room temperature it is solid, at maybe 500K or similar it can be easily ...
1
vote
1answer
6 views

Cathode region in corrosion

The anode region is on the iron where the following reaction occurs: $$ Fe_{(s)}\rightarrow Fe^{2+}_{(aq)}+2\,e^- $$ and at the cathode region, the following reaction occurs $$ ...
0
votes
1answer
10 views

How can I find the stoichiometry of a reaction from the volumes of the reactants and products given?

I have volume $V$ of gas $\ce{A}$ and an equal volume $V$ of gas $\ce{B}$ at room temperature and pressure. I mix, ignite, and find I have a gas (mixture of $\ce{A}$ and product $\ce{C}$) at room ...
1
vote
1answer
13 views

Electron shell, how do they know it?

I started to learn Chemistry with something like Hidro have 1 electron in the first shell, Oxigen have 2 electron in the first shell and 6 electron in the second shell... But I don't really understand ...
3
votes
1answer
245 views

Do chemicals have an expiry date?

A bonus question would be, if so, why? Is it because it decomposes and hence the expiry date is calculated out?
0
votes
0answers
15 views

Bohr's Theory about the hydrogen atom [on hold]

borh's theory for the hydrogen atom was discarded because he viewed....a) energy levels as quantized b) electrons as moving in circular orbits c) the nucleus as small and charges d) electrons outside ...
2
votes
1answer
27 views

Any home made tricks to fill up a baloon that floats?

These days there are a number of fancy balloons available, some of them are very beautiful. As always, they loose their gas overtime and don't rise anymore. Some of those new type balloons appear to ...
1
vote
0answers
41 views

NMR spectra problem

I synthesized the Wittig salt p-carboxybenzyltriphenylphosphonium bromide. Below is the proton NMR spectrum I measured. I'm having a little problem of matching the peaks to the hydrogens, especially ...
-1
votes
1answer
34 views

How does light get refracted through five lenses in a component of a spectrometer? [on hold]

Question three in my Pre-lab questions for my Physical Chemistry practical is causing me problems. If a parallel beam of light hits the first lens with focal length 2F it will cause the light to ...
5
votes
2answers
236 views

Nomenclature for different types of ice

How many types of ice exist and what is their nomenclature? I know that the ice on Earth is $I_h$, but why so?
0
votes
0answers
20 views

Why does ice water taste tastier than normal water? [duplicate]

Why does cool water taste tastier than normal water? I don't understand if water has no taste, color & odor. Then why does cool water taste different compared to room temperature water?
3
votes
3answers
48 views

How to make permanent ink that appears after some time?

I'd like to ask, how to make permanent ink, that will be invisible when used, but after like 30 minutes it will appear (preferably dark color)? Thanks.
0
votes
0answers
19 views

Since I've learned only how n and Z affect the radius, if some Z numbers of elements are given, how should I list them?

According to my teacher we should group them according to their period and than their group, but that isn't always true. What should I do?
-1
votes
0answers
19 views

How to figure out which metals will be oxidized by aluminium ions? [on hold]

Which of these metals will be oxidized by the ions of aluminum? Why? How did you figure out that answer? A. magnesium B. zinc C. chromium D. iron E. nickel
14
votes
4answers
3k views

Hypothetical: What happens to water as pressure increases to infinity?

I've asked a similar question here but the answer given shows the behaviour of water under general conditions. I'd like to know what the behaviour of water is like as pressures increase towards ...
0
votes
1answer
24 views

Elasticity of latex

Latex is a natural resources and the elasticity can be increased by heating it with sulphur. My question is why they are different elasticity of latex? I mean like rubber gloves have a good elasticity ...
0
votes
0answers
24 views

Could someone display the mechanism for the reaction of benzophenone with sodium borohydride?

I wondering about the details of the question like bonds broken/formed. As well, just general information on the reduction of ketones would be helpful.
1
vote
1answer
22 views

Which chemicals could be used to dissolve Polybutylene Terephthalate (PBT), but not dissolve brass?

This is for a recycling project, I am looking to recover brass pins from electronic connectors made of glass reinforced Polybutylene Terephthalate (PBT). The objective is to find a chemical which ...
2
votes
2answers
33 views

Is this reaction at equilibrium?

The following equilibrium occurs: $$\ce{2 NOCl(g) <=> 2 NO(g) + Cl2(g)}$$ A gaseous mixture of $\ce{NOCl}$, $\ce{NO}$ and $\ce{Cl2}$ is put in a container. After a few minutes it is found that ...
0
votes
1answer
24 views

In the following reaction, will the ratio between substances be 3:1?

In the reaction $$\ce{3 C2H2(g) <=> C6H6(g)}$$ will the ratio of $\ce{[C2H2(g)]}$ to $\ce{[C6H6(g)]}$ at equilibrium be 3:1? How is the mole ratio related to the equilibrium (or lack thereof) ...
0
votes
0answers
37 views

How to simulate chemical reactions in GAMESS?

I am rather newbie in GAMESS field but finally could learn to make input files for most molecular simulations and even could use TD-DFT and excited states ( special thanks to Geoff Hutchison for his ...
0
votes
0answers
13 views

Percentage composition and chemical formulas [on hold]

A compound with the formula $X_4 P_2 O_7$ has 33.94% of its weight in oxygen. Determine the number of X atoms in 880g of compound.
2
votes
1answer
41 views

Which has a greater entropy?

Which of the following has greater entropy? a. $\ce{CH3COOH~ (aq)}$ or b. $\ce{CH3COO^{-}~ (aq) + H+~(aq)}$ They are both in the same state, and have the same number of particles.. so how do ...
1
vote
1answer
24 views

Rotational states of a molecule

How can you determine the possible rotational states of a molecule? Atkins Physical Chemistry book says that for linear molecules there are two possible rotational states, but what is the general ...
4
votes
1answer
20 views

How does dimethyl sulfoxide transport other molecules through skin?

Wikipedia says: Use of DMSO in medicine dates from around 1963, when an Oregon Health & Science University Medical School team, headed by Stanley Jacob, discovered it could penetrate the skin and ...
2
votes
1answer
67 views

Why does delocalization of $\pi$ electron bring stability?

My book mentions that Delocalization of $\pi$ electrons makes a compound stable as the process of delocalization involves loss in internal energy. This is the synopsis of resonance. But how does ...
1
vote
1answer
13 views

Please help me how to find the valence of transition metals?

For example Fe(Z=26) Short formula: $1s^2 2s^2p^6 3s^2p^6d^6 4s^2$. If we make the electronic formula we get 4 single electrons (s=1/2), which means that the valence in normal state is 4, but in the ...
0
votes
1answer
24 views

Will room-temperature water in a sealed flask evaporate?

Some liquid water is present inside a sealed flask at room temperature. Is water evaporating, and is the system at equilibrium? First of all, can water evaporate in a sealed flask at room temperature? ...
0
votes
0answers
10 views

Curly arrow mechanism for reaction between sodium borohydride and water?

I was asked to compare the reaction between sodium hydride and water and sodium borohydride and water. I know that the former acts more violently than the latter, but apparently I must use a curly ...
1
vote
0answers
18 views

Cleaning up equipment contaminated with ethidium bromide?

I want to clean up some old equipment that was used to visualize nucleic acids with ethidium bromide. It's a UV table, built from glass and metal (stainless steel, I assume). Ethidium bromide is ...
2
votes
0answers
16 views

Non stationary effects of molecular orbitals

We have been learning a bit about molecular orbitals in class. However, we have always considered things under a quasistatic approximation. What are some effects that can only be explained by not ...
1
vote
1answer
22 views

Organic chemistry naming - ascorbic acid - weird numberings

This might be a beginner's question, but hey I have to start somewhere. If I look up the IUPAC name of ascorbic acid, I find this: ...
0
votes
1answer
26 views

Determine the bond angle in a compound [on hold]

How can we find the bond angle between 3 atoms in a compound? Please specify an equation which can be used for all compounds.
3
votes
2answers
30 views

What is tryptose

Occasionally, I work with lauryl tryptose broth for growing coliform. Being a chemical engineer, I suspected at the start that tryptose is a type of carbohydrate because of the -ose syffix. However, ...
-1
votes
0answers
10 views

How to calculate the composure of a mixture by determined mass loss during heating? [on hold]

$$\ce{2NaHCO3 -> Na2CO3 +H2O +CO2}$$ A loss of $6.2~\mathrm{g}$ was seen when $25~\mathrm{g}$ of a mixture of sodium carbonate and sodium hydrocarbonate were heated to constant weight. ...
0
votes
0answers
8 views

Is hydrated calcium silicate a good anticaking agent?

I work in a salt production factory and I want to make a purchase for hydrated calcium silicate as an anticaking agent for salt. Is it a good anticaking agent for salt and what is the perfect ...
0
votes
1answer
43 views

Why is nitration of veratrole specific in these positions?

Why do we not need $\ce{H2SO4}$ as acid catalyst for di-nitration of veratrole? Why does the 2nd nitro group go to positions 4 or 5, following the directing effects of the methoxy-group? Doesn't the ...
0
votes
1answer
23 views

Is it relevant to pursue a master degree or a doctorate when applying to a job in the petroleum field? [on hold]

I have a few more questions of this type for an interview. ( University work ) Thanks in advance.
2
votes
2answers
36 views

What is the difference between nuclear fission and nuclear fusion?

I always mix up the definition of nuclear fission and nuclear fusion. So, what is nuclear fission and nuclear fusion, and an example for each?
1
vote
1answer
18 views

Is the refractive index of a solution of four substances is a median of the four subtances' refractive index?

I need to determine the purity of a solution and we need to discuss about the 'theoretical' refractive index of the substance that we are supposed to have. Thank you!
2
votes
2answers
59 views

How many grams of water would you add to 1.00 kg of 1.44m CH3OH(aq) to reduce the molality to 1.00 m CH3OH?

How many grams of water would you add to 1.00 kg of 1.44m $\ce{CH3OH (aq)}$ to reduce the molality to 1.00 m $\ce{CH3OH}$? I am absolutely stuck on the last question of my mastering chemistry ...
5
votes
1answer
152 views

Why do the d orbitals have these notations?

Why do the d orbitals have the following notations: $xy, yz, xz, z^2$ and $ x^2-y^2$? What do they represent in their wave-functions?
1
vote
1answer
34 views

Define “reactivity”

Does reactivity of a compound depend on kinetic factors, thermodynamic factors, or both? i.e. how is reactivity defined? For example, out of a) 2-bromopropane and b) 4-bromobutan-2-one, which is more ...
0
votes
0answers
18 views

How can a melting and a freezing point of ice be the same [duplicate]

How can a freezing and a melting point of ice be the same ??

15 30 50 per page