Chemistry Worksheet
Interpreting Chemical Equations
Name: ______________________________
Block: ______ Date: _________________
Substances are converted into new substances in chemical reactions. Chemical reactions allow
us to ride in cars, cook food, and above all, live. The functioning of a human body is dependent
on chemical reactions.
Chemical reactions can be represented through equations. In a chemical equation, a reaction is
represented primarily through symbols for elements and compounds. Chemical equations can be
interpreted by considering the substances involved in the reaction or, alternatively, by
considering the particles involved in the reaction.
The following is an example of how a chemical equation can be interpreted on a substance or
particle level:
Example:
Chemical equation (for the burning of wax in a candle)
C25H52 (g) + 38 O2 (g) ↓ 26 H2O (g) + 25 CO2 (g)
Word equation considering the substances involved:
Gaseous wax reacts with oxygen gas to form water vapor and carbon dioxide.
Word equation considering the particles involved:
One molecule of the wax reacts with 38 molecules of oxygen to form 26 molecules of
water and 25 molecules of carbon dioxide.
Your turn:
1. Chemical equation (for the burning of ethane, part of natural gas):
2 C2H6 (g) + 7 O2 (g) ↓ 6 H2O (g) + 4 CO2 (g)
Word equation considering the substances involved:
Word equation considering the particles involved:
2. Chemical equation (for the burning of magnesium in fireworks)
2Mg (s) + O2 (g) ↓ 2MgO (s)
Word equation considering the substances involved:
Word equation considering the particles involved:
Question: Why are “formula units” needed for this word equation?
Chemistry Worksheet
Name: ______________________________
Interpreting Chemical Equations
Block: ______ Date: _________________
3. Chemical equation (the explosive reaction between H2 and O2.):
2 H2 (g)
+ O2 (g)
→ 2 H2O (g)
Word equation considering the substances involved:
Word equation considering the particles involved:
4. Chemical equation (the explosion of nitroglycerin):
4 C3H5N3O9 (g) → 10 H2O (g) + 12 CO2 (g) + 6 N2 (g) + O2 (g)
Word equation considering the substances involved:
(Hint: When only one reactant is present, use “decomposes” rather than “reacts with.”)
Word equation considering the particles involved:
5. Chemical equation (for the decomposition of CaCO3):
CaCO3 (s) → CaO (s) + CO2 (g)
Word equation considering the substances involved:
Word equation considering the particles involved:
I have had all of my questions on this assignment answered through self-study or asking. I
understand the concepts, and am ready to receive credit.
Signature ______________________