KEY
Activity 151-3
Chemical Formulas for Ionic Compounds
Directions: This Guided Learning Activity will focus on determining the correct chemical formula and
ionic charges for an ionic compound. These skills are important for predicting the products of chemical
reactions (a topic discussed in another GLA). In Part A, the basic terminology and periodic trends for
ionic formation are discussed. Part B focuses on determining the correct chemical formula for compound
that forms between two ions and based on nomenclature. Part C expands to include ions with variable
charge. The worksheet is accompanied by instructional videos. See www.canyons.edu/Departments/
CHEM/GLA for additional materials.
What is a cation? ____________________________________________________________
What is an anion? ____________________________________________________________
How do ions form? ___________________________________________________________
Part A – The Basics
How can you use the Periodic Table to predict the most common charge of an ion?
Chemistry Guided Learning Activities
Activity 151 – 3
College of the Canyons
Page 1 of 4
What are some common polyatomic ions?
Ammonium
__________________
Sulfate
_______________ _____
Hydroxide
__________________
Chlorate
---- ClO3
Acetate
__________________
Phosphate
Nitrate
__________________
Carbonate
-
_________________
_
__________________
Part B – Writing Formulas for Ionic Compounds
Write the formula for the compounds that result from each of the pairs of ions:
Na+
O2Mg2+ NO3NH4+ SO42________
________
________
Al3+
CO32-
________
Write the ions and the formula of each of the compounds given:
Lithium acetate
Ions:
Formula:
____
____
________
barium hydroxide
____
sodium nitride
calcium carbonate
____
____
____
____
____
________
________
CuSO4
Mg(NO2)2
________
Part C – Ions with Variable Charge
Cr(NO3)2
Ions:
____
____
Fe2O3
____
Chemistry Guided Learning Activities
Activity 151 – 3
____
____
____
____
____
College of the Canyons
Page 2 of 4
Write the formula for the compound resulting from each pair of ions:
Fe2+
OH-
Pb4+
O2-
nickel (II) ion +
phosphate
copper (I) ion +
Fluoride
________
________
________
________
Determine the ions (including charge) that make up the following compounds:
Part D – Extra Practice in Writing Ionic Compound Formulas
Write the formula for each ion in the box with the name of the ion. Then write the formula for the
compounds formed when each cation is combined with each anion.
Chemistry Guided Learning Activities
Activity 151 – 3
College of the Canyons
Page 3 of 4
Potassium
Ammonium
Copper II
Lead IV
________
________
________
K+
________
Chloride
________Cl-
KCl
Acetate
________
Sulfide
________
Carbonate
________
Phosphate
________
Chemistry Guided Learning Activities
Activity 151 – 3
College of the Canyons
Page 4 of 4