What A>B>C does

A>B>C is a simple graphical demonstration of the progress of a sequential reaction of the form

A>B>C will allow values for the rate constants k₁ and k₂ to be entered, together with the length of time the reacion is allowed to run. A graph is then plotted showing the variation of the concentrations of the three components (A, B, and C) during the reaction.

Note that this application can be used with Risc OS 3.1 or later, but requires the presence of the Toolbox modules. The latest versions of these modules are available by download from RISCOS Ltd (http://support.riscos.com/Support/Updates/index.htm) or Castle (http://www.iyonix.com/32bit/system.shtml). As a last resort contact the author if you have problems obtaining versions suitable for use with this software. The software is 26/32 bit neutral, but will require a 32 bit version of the SharedCLibrary module to be installed. This is available from the Castle (Iyonix) site above.

These notes refer in particular to A>B>C version 1.05 and later.

A>B>C is released as Freeware. The latest version can be obtained from the author's web site, at http://www.chris-johnson.org/software/. The author is always ready to listen to bug reports, comments and suggestions.

Running the Application

This software can be run from the desktop by double clicking on the !A>B>C icon in a directory viewer to install its icon on the icon bar. Clicking SELECT on the iconbar icon will open the input window ready to enter your values of rate constants and reaction time

The Input Window

The input window is shown at the left. The topmost field displays the starting concentration for the reactant A in the reaction. This is fixed at 100 concentration units and cannot be changed.

Below this are two fields for the entry of the two rate constants k₁ and k₂ for the reaction steps A to B and B to C. These rate constants can be entered in scientific format if necessary.

Finally it is necessary to enter the time for the reaction. Thus you can follow the reaction for a very short time with very low conversion, or a much longer time with a high conversion. The time scale required will depend upon the values of the rate constants, particularly k₁, the lower the rate constant, the longer the time required.

Clicking on the Plot button will then show a graph of the progress of the reaction using the parameters you have entered in the input window.

Clicking on the Close button will remove the input window from the screen. The values entered will be retained, and the window can be reshown by clicking on the iconbar icon.

Clicking on the Clear button will blank the input window of any values you have entered.

The Graph

The Graph Menu

The graph menu offers the following options.

Scale B

If the parameters you have entered result in a very small concentration of B, then the graph can be autoscaled, by clicking on Scale B. The concentration is scaled in factors of 10, so, for example, if B remains less than 1%, but at some point is greater than 0.1%, the line for B will be scaled by a factor of 100. The annotation at the top of the graph will reflect the scaling factor. To turn off scaling, click on Scale B again.

Scale C

If the parameters you have entered result in a very small concentration of C, then the graph can be autoscaled, by clicking on Scale C. The concentration is scaled in factors of 10, so, for example, if C remains less than 1%, but at some point is greater than 0.1%, the line for C will be scaled by a factor of 100. The annotation at the top of the graph will reflect the scaling factor. To turn off scaling, click on Scale C again.

To MultiPlot

Clicking on this option will bypass the "Save as" dialogue, and attempt to load the current graph directly into !MultiPlot. If !MultiPlot is not running, then A>B>C will complain. If MultiPlot has no data, or the previous data has been cleared, then a new graph will open showing the exported data. The action on further exports from A>B>C will depend upon the MultiPlot export settings in A>B>C preferences. See the help notes for !Multiplot for further information on the display of multiple graphs.

Save as

This leads via a submenu to a Save as dialogue, which allows the export of the graph data either in MultiPlot format or standard CSV format. A file saved in MultiPlot format can be loaded at some later time into MultiPlot, in which it can be customised and converted to a draw file for loading into e.g. a DTP program.

Saving in CSV format allows the data to be loaded into a spreadsheet such as !Eureka. An extract from an example CSV export is shown below (only the first few data are shown).

"Demonstration of series first order reactions"
"k1 =",1.7
"k2 =",6.8
"time","[A]","[B]","[C]"
0,100,0,0
0.0116667,98.0362,1.88767,0.076125
0.0233333,96.111,3.5943,0.294724
0.035,94.2236,5.13443,0.642019
0.0466667,92.3732,6.52146,1.10534

Help...

Opens the HTML manual (which you are currently reading) in a browser.

The Iconbar Menu

Info

Following the submenu arrow raises a standard information window, including the version number and date of issue. This is the information that should be quoted in any communication regarding the application. The information window also contains a button labelled "Web site". Clicking this button will attempt to connect to the A>B>C download site, launching a browser if necessary, where the latest version should be available.

Help...

Opens the HTML help files (which you are currently viewing) in a browser.

Choices

This dialogue is where all the application defaults are set. At the foot of the dialogue are the three buttons Save, Cancel, and Set.

• Set will apply the choices with immediate effect. Any changes made will last only until !A>B>C is quit.
• Save will apply the choices with immediate effect, and will also save the settings so they will be reloaded when !A>B>C is run on another occasion.
• Cancel will simply close the dialogue, and any alterations made will be ignored.

In the main part of the dialogue you can set some default actions of !A>B>C.

Font style



The style and the size of the font used to label and annotate the graph can be set up here.

Graph lines



The style attributes for the three data lines on the graph are set here. The number of line segments determines how smooth the curve of the lines appears to be (each curve is made up of a number of straight line segments). The number of segments can be changed using the bump arrows in the range 50 - 200 segments.

The colour of the data lines can also be changed. The menu button to the right of each colour patch will raise a standard colour menu.

MultiPlot export



If you wish to use a high quality copy of the graph in a document, for example, the data can be transferred to !MultiPlot. This allows a high quality print out, or exporting as a draw file.

The data can be exported to !MultiPlot either as a set of points, or as a continuous line. When exporting, a new graph will be produced every time if the Clear MultiPlot window button is ticked. If it is not ticked, then the data will be added to the current graph being displayed in MultiPlot. This enables more than one set of curves to be included on the same graph.

Quit

This option allows the application to be closed down and removed from the iconbar.