3. Word equation
A word equation should state the
reactants (starting materials), products
(ending materials), and direction of the
reaction in a form that could be used to
write a chemical equation.
7. Thermal decomposition.
Elements can form
compounds in
chemical reactions
and reverse can also
happen. When heat is
used to break down a
compound the
reaction is called a
thermal
decomposition. This
type of reaction is
used in many
industries, including
extraction of metals
from their minerals.
8. Thermal decomposition.
Some compounds can decompose to
form other compounds. Metal
carbonates do this. They are
compounds containing a metal, carbon
and oxygen. Many metal carbonates are
found naturally and have many uses.
For example calcium carbonate is found
in limestone, chalk and marble.
12. How to name a compound
If a compound contains two elements
plus oxygen, the ending of the name of
one element is changed to –ate. The –
ate means with oxygen.
For example, a compound of zinc,
sulphur and oxygen is zinc sulphate.
14. Questions
1. What happens in all chemical
reactions?
2. Write word equation for following
reactions
A) Hot copper metal reacts with
chlorine gas to form solid green copper
chloride.
B) Non metal carbon burns in oxygen
gas to form only carbon dioxide gas.
15. Questions
3. a) How would you thermally decompose
silver oxide.
b) Write a word equation for the
reaction.
4. What elements are in
a) Sodium Phosphate b) Lead Nitrate
5. Write a word equation for thermal
decomposition of calcium carbonate.
