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HP 33S - Chemistry Student Needs Programs - Printable Version

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HP 33S - Chemistry Student Needs Programs - Rhyleigh - 10-26-2007

Does anyone have an idea of where I can find programs written for the HP 33S that will help me to solve some of the math formula questions in my Chemistry Lab?

I have already bought the 33S but I cannot figure out how to write a program for de Broglie's Equation, or Bohr's Equation, etc.

Your feedback is greatly appreciated.


Re: HP 33S - Chemistry Student Needs Programs - Ed Look - 10-26-2007

Hmmmm... do you know or have you done any programming?

If not, read the programming sections of the 33S manual thoroughly, and practice a few easy tasks while you're at it.

But basically, you first choose a label letter and then begin your program steps from there.

Let me first recommend you follow the three fundamental steps in this order:

pseudocode- just scribble down, in bad English or whatever language even, your basic ideas of what you want your program to do and a little of how you might want to get it there.

flowchart- look up... I guess these days you can use Google or some such... the symbols that represent the various types of computer program execution steps, i.e., I/O, formatting, math or other (like storage, etc.) operation, branching, and testing. Then use your psuedocode as a guide to draw your flowchart, which is a skeletal diagram of your program.

program- finally, using your flowchart, write your program in the steps of your chosen computer language, which I suppose, in this case is RPN keystroke programming.

Now, I think keystroke programming on a HP scientific calculator is easier than writing a program for a minicomputer or mainframe or even the PC. This is because each keypress expresses your desired instruction step in the program.

Incidentally, his name was Louis de Broglie, and most likely you are referring to his famous "matterwave" equation which linked solid matter with wave properties,

wavelength = Planck's constant / momentum

(I apologize- I don't know how nor even if I can insert Greek letters or mathematical symbols here)

If this equation is what you want, it is at the simplest level, a division problem. If so, then left shift (green arrow) PRGM (R/S key) will get in into the programming space. Then left shift LBL (+ key) and choose a letter from the alphabet that you would like. Now, you are fortunate, since Planck's constant, h, is a part of the 33S constants library. Access that by right shift (purple arrow) MODES (on the top right below the display panel) and use the navigation key in the middle to scroll around and find h. Then hit ENTER to choose it and insert it in your program. Now you will have to use an inputting step that will halt your calculator so you can put in your momentum value when you run the program: key in R/S, which should read, "STOP". (When you run the program, after keying in your momentum value, you'll have to hit R/S to continue the program execution.) At this point, key in divide and then right shift RTN (+ key), and you're done.

Now, I leave it to you to figure you how to program in the Rydberg equation (it's not called Bohr's equation, though it is based on Bohr's model). But I think you're in luck again, as I suspect the Rydberg constant for the hydrogen atom, R, (and this is not the gas constant R)... well, they may call it something else, you'll have to check, but look up the value of the Rydberg constant in your textbook and you can then identify it in your 33S constants library.

Study hard.


Re: HP 33S - Chemistry Student Needs Programs - Dave Shaffer (Arizona) - 10-26-2007

If you are trying to evaluate an equation by looking for the value of an unknown quantity while you have all the other quantities, you can use the solver.

Basically, you enter the equation, give it the variables you know and it will return the value of the unknown.

You can also just enter an equation to be evaluated for various input values.

As Ed suggested, read the appropriate chapters (6 and 7) and try the examples in the manual.


Re: HP 33S - Chemistry Student Needs Programs - Ed Look - 10-27-2007

If he's going to type in the equation and use the solver, he might as well save it to the Equation Library (right shift EQN [the STO key]). To me, that accomplishes the same thing, to have it stored in memory somewhere in some form to be used over again.

Wait'll he gets to p-chem.