js-chemistry-codes

Scripts written in JS for doing random bits of chemistry in the Numbas system. No affiliation with the official Numbas project/development team

The codes currently stored here are

• Half-eqn-balancer v1: an early attempt to create a code to randomly generate and balance cell equations, based on a list of random half-equations
• Half-eqn-balancer v2: a complete rewrite of v1 which changed the aproach to generating the equations and increased the flexibility of the code. Also added a few extra features to make questions more realistic.
• basis_set_praser+fn_calculator.js: a code which can take STO-nG and l=mnoG (Pople split-valence) type basis sets, and calculate how many basis functions would be generated for model a simple organic molecule (containing atoms from, at present, the top row only). Can deal with * and ** variants, and can currently parse +/++ variants but these are not taken into account for calcualtions.
• Random_Organic_Molecular_Formulae.js1: generates a randomised organic compound using the degrees of unsaturation formula. Specifically built for the basis set calculator. Generates only the molecular formula and makes no attempt at generating connectivity.

half-equations.json

The half-equations.json file contains a list of 30 simple electrochemical half-equations. By simple I refer to an equation in which a sigle species gains elctrons to product a single reduced species. All equations in this document are written as reductions i.e. M⁺ + e^- -> M. If oxidations are required then simply flip the order in which you call elements/concatenate.

All keys which contain chemical species are formatted with LaTeX so in order to display them in questions the latex(...) fuction is necessary;

    \[ 
      \var{latex(equation)} 
    \]

The following keys are held for each equation;

• id: an integer which allows them to be picked randomly. Must be entered manually and adjusted if equations are added/removed, and must also be continuous
• equation: the half equation
• molLHS: mole equivalents of the left-hand side species
• molRHS: mole equivalents of the right-hand side species
• LHS: the left-hand side species, rendered with LaTeX
• RHS: the right-hand side species, " "
• emol: the mole equivalents of electrons tranferred during the process
• E0: the electrode potetial of the half-equation

This file (in its current iteration, v1.0 at the time of writing) has 30 half-equations, allowing for 870 combinations (I think). This should be sufficiently random such that no-one in a group should have the same question.

N.B. not all codes use all the fields from this json. Check the section for each script for more detail!