Chemistry 101

[Michaelangelica]

Thankyou for your help.

 

Sorry i'm still lost

I don't have a starting point.

 

I need absolute basics

[hallenrm]

Well let me try.

 

Basics first! Ions are atoms or melecules that are either deficient or surplus of electrons. Puting it simply it means that the number of electrons and protons in an ions is not equal. When the electrons are more the ion is called an anion, and otherwise a cation. Since electrons are negatively charged this means that an anion is negatively charged like the chloride ion Cl- and cations are positively charged like the hydrogen ion H+.

 

Let us now turn to the second word exchange, the cations and anions exist together, so as to maintain a neutral charge. But an anion can have any cation as its companion, much like young boys and girls. Some anions have a stronger attraction (call it preference) for certain cations, so when they are offered the choice, they would like to retain the cation they have stronger attraction for.

 

Now consider the scenario, a substance is made up of X cations and Y anions (x and Y are not numbers but names), now another substance is added to it which has Z cations and Q anions. The Y anions bind more strongly to Z cations then they do to X cations, so the mixing of the two substances results in Z cations being retained by the Y anions. The cations get exchanged between Y and Q anions.

 

So now that you understand what the terms cation exchange means, try to figure out the capacity part of it,

 

Think, You cannot succeed without thinking :)

[Michaelangelica]

OK

Thanks a lot I do appreciate your posts BUT?

I'll print out what you say read it several times and have a BIG THINK

 

But I don't think I have the background to really understand

(I need to visualise things to really understand them)

Will get back to you

MB

[Mercedes Benzene]

But I don't think I have the background to really understand

(I need to visualise things to really understand them)

 

Feel free to ask questions if you still need help with something!

I'm off to school now, but I will be more than happy to assist you in your quest for chemical knowledge once I return. :shrug:

[Michaelangelica]

Thak you all for helping a Bear with Little Brain.

 

OK so it seems plant exchange of chemicals/nutrition happens at an atomic level (?)

 

Some little bits have a +itive charge some a negative (Why?)

 

Somehow some bits are attracted to other bits (Because a +itive attracts a -itive??).

 

So how can you enhance CEC?(which hopefully makes for better plants?)

 

They say Vermiculite has the highest CEC (Why?)

 

Also that Chracoal helps CEC (Why?)

 

Where does the Ph test fit into this?

[hallenrm]

Thak you all for helping a Bear with Little Brain.

 

You are always welcome!

 

OK so it seems plant exchange of chemicals/nutrition happens at an atomic level (?)

 

Yes, but not only with plants!

 

Some little bits have a +itive charge some a negative (Why?)

 

Such are the ways of nature!

 

Somehow some bits are attracted to other bits (Because a +itive attracts a -itive??).

 

Yes, you have got it right!

 

So how can you enhance CEC?(which hopefully makes for better plants?)

 

They say Vermiculite has the highest CEC (Why?)

 

Also that Chracoal helps CEC (Why?)

 

Sorry, but it is almost impossible to ehance CEC of plants, just as it is to enhance your digestivity.

 

Some plants have high CEC, that is their due to nature, their molecular constitution.!

 

Charcoal is only a good adsorbent, it can remove some substances from a substance (liquid or gaseous), by doing so it may be helping CEC in some cases, but left to itself charcoal cannot initiate cation exchange, for the simple reason, it is not ionic.

 

Where does the Ph test fit into this?

 

It is not Ph it is pH, it can facilitate cation exchange because a low pH means a high concentration of hydrogen ions (which are incidentally cations) often hydrogen ions can be exhanged for cations with higher electric charge viz Ca2+ and Fe3+, for example.

 

:hihi:

[Michaelangelica]

impossible to ehance CEC of plants, just as it is to enhance your digestivity.

Sorry, I ment enhancing the soil's CEC not the plant's CEC

Thanks for you help

[dlm]

If it's not too much trouble can someone explain to me orbital diagrams and graphs?

 

Why are the s orbitals shaped like a circle while the p and d orbitals are shaped like a dumbbell and clover. Do orbitals have nodes? If so what purpose do they serve?

 

I tried reading the textbook but I can't make any sense of it.

 

Also if I were given a list of cations and anions how would I list them in increaing order through using the periodic table? For example, which is larger K+ or Cl-?

[hallenrm]

I would like to help you indeed, but to do that most effectively I would like to know what is your present level of education? Are of aware of schrodingers equation, quantum mechanics etc.

 

Reply soon to get back an helpful response! :(

[Mercedes Benzene]

If it's not too much trouble can someone explain to me orbital diagrams and graphs?

 

Why are the s orbitals shaped like a circle while the p and d orbitals are shaped like a dumbbell and clover. Do orbitals have nodes? If so what purpose do they serve?

 

I tried reading the textbook but I can't make any sense of it.

 

::sigh:: This is one of the hardest things about chemistry (in my opinion) to try to explain to someone. I have to go get ready for school, but when I get home I'll try to put something together that may help you. :)

In the mean time, maybe someone else here could help you.

[Jay-qu]

well I have never heard of orbitals been shaped differently.. im sure its purely conceptual and has nothing to do with physical shapes.

[dlm]

I would like to help you indeed, but to do that most effectively I would like to know what is your present level of education? Are of aware of schrodingers equation, quantum mechanics etc.

 

Reply soon to get back an helpful response! :cup:

 

Well, I just started my first year of university and am taking an inorganic chem course. I did read about schrodingers equation and quantum mechanics but I don't really remember much.

[hallenrm]

Well then let me try.

 

You know that the various models of the atom proposed by various scientists like Rutherford and then Neils Bohr had some inherent contradictions or limitations, they did not blend very well if the existing knowledge about charged particles.

 

Schrodingers equation was an attempt in the direction to overcome all such drawbacks. The equation proposed by [Wiki}Erwin Schrodinger[/Wiki] was indeed the result of a revolutionary thought. A solution of this equation for the Hydrogen atom, explains the spectrum that is produced when em radiation interacts with them marvelously. All that quantum mechanics AKA schrodinger's equation says is that if you can properly set up such a equation for any atom or molecule, you will get the possible energy states as its possible solutions.

 

If you even faintly remember this equation you would also remember the phrasw wave function. A wave function is a mathematical function that describes the state of an atom. Like most mathematical function this function often represented by the greek letter psi can be plotted against the space coordinates, x,y,and z.

 

The atomic orbitals are in fact such a plot. It is further claimed by this theory that if you plot the square of psi against space coordinates you can get a visual picture of the probability in space where an electron, in an atom for which the equation was set, can be found.

 

So you see the pictures of atomic orbitals that you find in your textbook are in fact nothing more than visualization of such plots. A point in these plots, as in p, d, or f orbitals that coincides with the zero can be said to be a point where no electron in that state can be found (according to the theory) on the contrary the spherical s orbital indicates that the maximum probabilty of finding the electron is within a sphere of that size. Mind you according to this visualization, an electron is equally likely to be found at the nodes.

 

Surprising, isn't it! :cup:

 

My only advice to you dear dim, is not to attempt to grasp it in a jiffy, these are ideas that require a few minutes of thought before they can percolate down your mind to produce what is called an understanding.

[dlm]

Thanks for the help...but I still don't get it. For example what does 3dx2-y2 mean? And what exactly do you mean when you say a point that coincides with zero? Are you talking about the axis, so any point on the x,y, and z axis is a point where no electrons are found?

[hallenrm]

And what exactly do you mean when you say a point that coincides with zero? Are you talking about the axis,

 

No I mean the point where the three axis meet.! And please don't appear so dumb, I am sure you are not. When I said orbitals indicate the probability of finding an electron at various points in space, you would not be asking

 

so any point on the x,y, and z axis is a point where no electrons are found?

 

If you followed me and tried to understand what I said. In addition there are textbooks which I solemenly hope you read!

[dlm]

One last question: How do I know the n value when calculating ionization energies?

[Michaelangelica]

Why can't the salt water swimming pool tecnology be up-scaled?

to produce fresh water from salt?