Chemical Equations Test Review- KEY
1. Identify and determine the meaning of symbols used in chemical equations. (chart copied into comp book)
2. Write a word equation given the description of a chemical reaction. (Show the state of each product and
reactant.)
a. The combustion of methane.
i. Methane (g) + Oxygen (g) → Carbon Dioxide (g) + Water (l)
b. The decomposition of hydrogen peroxide to form water and oxygen
i. Hydrogen Peroxide (l) → Water (l)+ Oxygen (g)
c. Solid calcium carbonate is commonly used in antacids because it reacts with the hydrochloric acid
found in the stomach producing aqueous calcium chloride, carbon dioxide, and water.
i. Calcium Carbonate (s) + Hydrochloric acid (aq) → Calcium Chloride (aq) + Carbon
Dioxide (g) + Water (l)
3. Write a formula equation given a word equation. (Convert the word equations developed in #2.)
a. Methane (g) + Oxygen (g) → Carbon Dioxide (g) + Water (l)
i. CH4 (g) + O2 (g) → CO2 (g) + H20 (l)
b. Hydrogen Peroxide (l) → Water (l)+ Oxygen (g)
i. H2O2 (l) → H20 (l) + O2 (g)
c. Calcium Carbonate (s) + Hydrochloric acid (aq) → Calcium Chloride (aq) + Carbon Dioxide (g) +
Water (l)
i. CaCO3 (s) + HCl (aq) → CaCl2 (aq) + CO2 (g) + H20 (l)
4. Balance formula equations. (Use the formula equations developed in #3.)
a. CH4 (g) + O2 (g) → CO2 (g) + H20 (l)
i. CH4 (g) + 2O2 (g) → CO2 (g) + 2H20 (l)
b. H2O2 (l) → H20 (l) + O2 (g)
i. 2H2O2 (l) → 2H20 (l) + O2 (g)
c. CaCO3 (s) + HCl (aq) → CaCl2 (aq) + CO2 (g) + H20 (l)
i. CaCO3 (s) + 2HCl (aq) → CaCl2 (aq) + CO2 (g) + H20 (l)
5. Identify the type of chemical reaction from the reaction description, word equation, or formula equation. (7
different types of chemical reactions: See previous Worksheets for practice problems.)
6. Determine if a reaction will occur and predict the products of single displacement reactions based on the
activity series of the elements.
a. Aluminum Bromide reacts with Chlorine gas
i. 2AlBr3 +3Cl2 → 2AlCl3 + 3Br2
b. Aluminum reacts with Hydrochloric acid
i. Al + HCl → AlCl3 + H2
c. Silver reacts with Sulfuric acid
i. No Reaction
d. Zinc acetate reacts with Lead
i. No Reaction
e. Sodium reacts with Water
i. 2Na + 2H2O → 2NaOH + H2
7. Accurately label the parts of a chemical equation. (reactants and products)
8. Identify if a reaction is endothermic or exothermic.
a. Exothermic- the word describes a process that releases energy in the form of heat.
i. Forming a chemical bond releases energy and therefore is an exothermic process.
ii. Exothermic reactions usually feel hot because it is giving heat to you.
iii. Combustion, Acid/Base, and Decomposition reactions
b. Endothermic - a process or reaction that absorbs energy in the form of heat.
i. Breaking a chemical bond requires energy and therefore is Endothermic.
ii. Endothermic reactions usually feel cold because it is taking heat away from you.
iii. Synthesis and Photosynthesis reactions
9. Define Catalyst
a. A catalyst increases the rate of a chemical reaction.
b. Unlike other reagents that participate in the chemical reaction, a catalyst is not
consumed by the reaction itself.