SNC2D0
Name_______________________ Date________________
Equations of Chemical Reactions
Chemical Reaction is a process in which atoms get rearranged and new substance(s) are
formed. All chemical reactions involve the conversion of starting materials, called
reactants, into new substances, called products. The products have different properties
than the reactants.
The Skeleton Equation

A chemical reaction is often described by writing a chemical equation.

Uses either words or symbols and formulas to describe the changes that occur
during a chemical reaction
Eg, Magnesium reacts with Hydrochloric Acid to produce Hydrogen Gas and Magnesium
Chloride.
Symbols: + and

are used to represent the underlined words in chemical equations:
Reactants: chemicals
before reaction started
Word Equation: name
of chemicals and
special symbols + and
 are used
Chemical Equation
(skeleton): chemical
formula of chemicals
with + and  symbols
are used
Atomic Diagram of
reaction
(skeleton)
Products: chemicals
produced as a result of
chemical reaction



The Law of Conservation of Mass: In a chemical reaction, the total mass of reactants is
equal to the total mass of products.
It implies that no atoms are destroyed and no new atoms are produced during a chemical
reaction. Instead, the atoms in the reactants of a chemical reaction are simply rearranged
to form the products. Chemical bonds between atoms are broken and new ones are
formed, and the atoms simply reconnect in new ways.
Common State Symbols in Chemical Equations:
Symbol
The difference between (l) and (aq) is:
Meaning
(s)
(l)
(g)
Practice.
(aq)
1. Use the following equation to answer
the questions:
Propane + oxygen  carbon dioxide + water
State the reactant(s):____________________________________________
State the product(s): ____________________________________________
What does the  represent in a word equation? _______________________
2. Write Skeleton Chemical Equations for these reactions.
a) aluminum hydroxide reacts with nitric acid to yield aluminum nitrate and water
b) lead (IV) nitrate reacts with sodium sulfate to yield lead (IV) sulfate and sodium nitrate
c) sodium hydroxide reacts with carbon dioxide to yield sodium carbonate and water
d) magnesium oxide reacts with hydrochloric acid to yield magnesium chloride and water
e) Zinc reacts with sulfuric acid to yield zinc sulfate and hydrogen gas
f)
iron (II) oxide reacts with aluminum to yield aluminum oxide and iron metal