(2.3) CHEMICAL EQUATIONS

(p144-145)

Recall: Word Equation

A word equation - states what reacts and what is

produced- uses words instead of formulas to

describe a chemical reaction

Word Equation-Examples

ex 1: magnesium + oxygen magnesium

oxide  what reacts what is

produced (reactants) (products)

Word Equation-Examples

ex 2:zinc + hydrochloric acid hydrogen + zinc

chloride

what reacts what is produced (reactants) (products)

Chemical Equation

A chemical equation uses chemical symbols and formulas to represent the reactants and products in a chemical reaction

Chemical Equation

From the word equation you can now write a chemical equation:

ex:a) sodium chloride sodium + chlorine

(word equation)

b) NaCl Na + Cl2(chemical equation)

Chemical Formulas The chemical formulas of most

elements are written simply as the symbol in the periodic table

ex: magnesium, Mg sodium, Na

But there are some elements that contain more than one atom.

For a list, see Table 2.9 p147

Chemical Formulas

Textbook p 147

CLASSWORK

Copy Table 2.9 (pg. 147) into your notes pg.147 “Learning Check” # 1 - 4

HOMEWORK

“Chemical Reactions and Chemical Equations” Worksheet