Chemistry Software for Education and Industry
Software engineered by Trevor Yerlett BSc PhD CChem MRSC MBCS
BALANCER – Chemical Equation Predictor, Balancer and Calculator
NEW! Version 1.1 – now released, with Empirical Formula calculation
An invaluable user-friendly tool for students, teachers and chemistry professionals
Screenshot of BALANCER Version 1.1 (it may take a few seconds to load)
BALANCER is a powerful chemical equation balancer which also does more than simply balance equations.
- Predicts products from reactants for many reaction types e.g. acid + base, preciptitation, organic combustion.
- Calculates moles, mass and gas volumes for balanced equation – choice of units.
- User can select from database of many chemicals or enter formulae explicitly
- User-defined formulae can be stored, e.g. for chemicals commonly used in calculations
Many students struggle with equation balancing, which they are often told can be done by ‘inspection’, or
‘trial and error’. This is OK for very simple examples but may not be straightforward for more complex ones.
By using rigorous mathematical methods, BALANCER can balance equations of any complexity, provided
there is a genuine solution. Of course, this does not remove the need for students to do hand calculations and
BALANCER is a valuable tool for setting examples, checking calculations, calculation of amounts, mass/mole
BALANCER’s unique predictor feature, predicting reactions, enables students to test their knowledge of
standard equation types.
HOW DOES IT WORK?
By applying the principles of conservation of mass of each element, and conservation of net ionic charge,
chemical equation balancing reduces to a purely mathematical problem. There must be the same number of
atoms of each species on both sides of the equation, and the overall ionic charge must be the same on both
sides of the equation. Reactions involving radioactive decay do not necessarily follow these rules, but these
are not currently handled by BALANCER.
By setting up a matrix of atoms and stoichiometric coefficients, we can obtain a set of simultaneous equations,
which can usually be solved uniquely by applying standard matrix algebra techniques.
For a simple example, consider the equation:
aCa(OH)2 + bHCl = cCaCl2 + dH2O
where a, b, c and d are the stoichiometric coefficients we need to find.
We can arbitrarily fix a as 1, and find the other values relative to a.
The simultaneous equations are then:
Ca atoms: 1 = c (1)
O atoms: 2 = d (2)
H atoms: 2 + b = 2d (3)
Cl atoms: b = 2c (4)
From equation (1), c = 1. Substituting in (4), b = 2. From equation (2) d = 2.
The balanced equation is then Ca(OH)2 + 2HCl = CaCl2 + 2H2O
PREDICTION OF REACTIONS
The unique Predictor feature enables prediction of complete reaction equations from reactants only, for many
standard reaction types. The raw unbalanced equation is automatically generated; it can then be balanced if required.
Currently available predictions, with examples:
Acid + Base e.g. H2SO4 + NaOH = Na2SO4 + H2O
Acid + Metal e.g. HCl + Zn = ZnCl2 + H2(g)
Acid + Metal Oxide e.g. MgO + H2SO4 = MgSO4 + H2O
Acid + Carbonate e.g. HCl + Na2CO3 = NaCl + H2O + CO2(g)
Double Decomposition (aqueous solution) e.g. CuSO4(aq) + Na2CO3(aq) = CuCO3(s) + Na2SO4(aq)
Metal Substitution (aqueous solution) e.g. Fe + CuSO4(aq) = FeSO4(aq) + Cu
Metal Substitution (heated solids) e.g. Al(s) + Fe2O3(s) = Al2O3(s) + Fe(s)
Complete Organic Combustion e.g. C6H14 + O2(g) = CO2(g) + H2O
Valency states, oxidation numbers, the reactivity series for metals, solubility data and other knowledge bases are
used to determine whether particular reactions are likely to occur.