The Molwt & ptpro functions
The many uses of the HP50g amaze me everyday. I stumbled upon these functions while taking College Chemistry. The following functions allow you to quickly calculate mole weight for formulas and access 25 different properties of elements. If you continue reading you can learn something new and get those questions correct on your exam! The MOLWT function can be used on the stack and inside of the periodic table by pressing the "Alpha" key. i.e while inside of the periodic table simply press the yellow key. You should see "Type symbol or formula" and for the stack just enter the formula.
Description: Returns the molecular weight for the specified molecular formula. It takes the formula as a string
(such as "H2O") or name (with certain restrictions, such as 'H2O'). It returns the molecular
weight. It chooses to use or not use units according to the Units Usage flag (flag 61: SI units if
clear, no units if set).
You can store a molecular formula in a variable, then use the variable name with MOLWT. You
should do this when you want to use MOLWT in an expression and the formula contains
parentheses or matches a command name. You must take care when naming a variable that
contains a formula string or name. Make sure the variable name isn’t a valid formula — for
example, start the variable name with a lowercase letter. (If the variable name is a valid formula,
using MOLWT with the variable name returns the molecular weight for the variable name, not for
the formula it contains.)
Access: Goto APPS: PERIODIC TABLE: MOLWT
Flags: Units Usage (61) Needs to be checked!
Example: C3o2=68.0318_g/gmol to enter this formula go to APPS: Periodic Table-Press the "Alpha" key enter a formula and press enter.
*For lowercase letter I recommend writing the formula on the stack. To do this "Quit" the periodic table and enter your formula on the stack as follows. Press the right shift key "RED/ORANGE" button, then press the Multiplication button " " then enter your formula. To calculate the mole weight press the MOLWT soft key option. The following formula will calculate 4 moles of sulfur and 2 moles of oxygen.
*For lower case letter such as Ca for calcium use RED SHIFT key and EVAL(chars)
This function is useful for accessing quick information about the element you are working with. By inputting the atomic number/symbol -space - (1-25) for the property of your choose *there is a menu for choices. Click PTPROP to see attached PDF.
Description: Returns the specified property for the specified element. It takes the element’s atomic number or
symbol as a name (with certain restrictions) and the property number. It returns the property,
usually a value or a string. It chooses to use or not use units according to the Units Usage flag
(flag 61: SI units if clear, no units if set). If you use PTPROP as an algebraic function, you must
use the symbol to define the element — you can’t use its atomic number.
Access: APPS ---> PERIODIC TABLE ---> PTPROP
Flags: Units Usage (61)
Input/Output: Atomic Number or Atomic Symbol then (1-25)
Example: for Hydrogen input 1 1 and press PTPRO. The HP50g will output 1.Because 1=Hydrogen the atomic number one is hydrogen and 1=Atomic number.
If you enter 1 2 and press PTPRO the HP50g will output the mass number for hydrogen. Some common property of elements that can be entered from the list of 1-25 are State (liquid, gas, metal, etc), Melting Point, Boiling Point, Family, Group, Crystal Structure & more.
*Click PTPROP above to see PDF chart.
Leave a comment for questions, suggestions or more hp50g tips
Have a question?