Why symbols beat words
So far we have written reactions in words. But using words to write a chemical reaction runs into a number of difficulties.
Written in words
The ratio of the atoms making up the compound is not shown. The word "water" says nothing about its two hydrogens and one oxygen.
Written in formulae
The ratio of the atoms in the compound can be known exactly. H2O states it directly.
What that gives us
Knowing the formulae opens three steps
- The reaction can be balanced.
- Once the balanced reaction is known, the mass ratios in which the compounds or elements must be mixed to obtain the maximum yield can be calculated.
- That keeps waste down and makes certain calculations easy.
A chemical equation
A chemical equation is a chemical reaction represented symbolically using chemical formulae.
So writing a correct equation takes a good knowledge of chemical symbols and chemical formulae alike — which we learned in chapters 3 and 10.