16.4. Net Ionic Equations http://www.ck12.org
Lesson Summary
- Single-replacement and double-replacement reactions often take place in aqueous solution, in which dissoci-
ated ionic compounds are more accurately represented as free ions. - Spectator ions do not participate directly in the chemical reaction. An equation that shows only the substances
in the reaction is called a net ionic equation. Net ionic equations must be balanced by both mass and charge. - The solubility rules can be used to predict whether a precipitate is produced from a given mixture of ions.
Lesson Review Questions
Reviewing Concepts
- Substances that are in which state(s) in a molecular equation are broken down into ions to make an ionic
equation? - One or more of three possible types of products are generally formed in a double-replacement reaction. What
are they? - What happens to a spectator ion during a chemical reaction?
- Which statement below is true concerning a net ionic equation?
a. The overall charge on both sides of the equation must be zero.
b. The overall charge on both sides of the equation must be equal. - Use the solubility rules to determine whether each of the following compounds is soluble or insoluble in water.
a. (NH 4 ) 3 PO 4
b. CaBr 2
c. AgBr
d. Li 2 SO 4
e. Mn(OH) 2
f. SrCO 3
g. Pt(NO 3 ) 2
h. Fe 2 (CrO 4 ) 3
Problems
- Write a balanced net ionic equation for the reactions represented by each of the following unbalanced molec-
ular equations:
a. Na 3 PO 4 (aq)+Fe(NO 3 ) 3 (aq)→NaNO 3 (aq)+FePO 4 (s)
b. HCl(aq)+Mg(OH) 2 (s)→MgCl 2 (aq)+H 2 O(l)
c. Na(s)+H 2 O(l)→NaOH(aq)+H 2 (g)
d. K 2 S(aq)+HBr(aq)→KBr(aq)+H 2 S(g) - Will a precipitate form when aqueous solutions of the following salts are mixed? If so, write the formula of
the precipitate.
a. CaCl 2 and Mg(NO 3 ) 2
b. K 2 CrO 4 and MgI 2
c. NaCH 3 COO and Ni(ClO 3 ) 2
d. Ba(OH) 2 and Al 2 (SO 4 ) 3