Writing Chemical Equations & State Symbols Example

Chemical equations are symbolic representations of chemical reactions.

Writing chemical equations Example: Hydrochloric Acid reacts with Sodium Carbonate to produce Carbon Dioxide, Water, and Sodium Chloride.

Reactions in Chemistry - reactants and products

The species to the left of the arrow are called reactants. The species to the right of the arrow are called products.

In symbolic form we write: Na₂CO₃ + HCl --> CO₂ + H₂O + NaCl

or by using state symbols : Na₂CO₃(s) + HCl(aq) --> CO₂(g) + H₂O(l) + NaCl(aq)

State symbols in chemistry : (s) = solid (l) = liquid (g) = gas (aq) = aqueous (dissolved in water)

Note: Writing chemical equations in CHEMIX the arrow must be replaced with the > sign.

In CHEMIX writing is straight forward - you do not have to use subscript or superscript.

Example - Writing chemical equations in CHEMIX:

Na2CO3(s) + HCl(aq) > CO2(g) + H2O(l) + NaCl(aq)

Balanced: Na2CO3(s) + 2HCl(aq) = CO2(g) + H2O(l) + 2NaCl(aq)

This reaction will produce CO2 gas, H2O will be formed and Sodium and Chlorine will stay in the solution as Na+ and Cl- ions

Note: In CHEMIX (Balance) you can even argument species in the equation by grams (g) or by moles (m).

Example: How many grams of sodium carbonate will produce 10 grams of CO₂ gas ?

Solution: Insert 10g (10 grams) in front of CO₂ :

Na2CO3(s) + HCl(aq) > 10gCO2(g) + H2O(l) + NaCl(aq)

By downloading CHEMIX more writing and balance examples will be available.