Page 148 - Theory and Problems of BEGINNING CHEMISTRY

CHAP. 9] NET IONIC EQUATIONS 137

Solved Problems

WRITING NET IONIC EQUATIONS
9.1. How many types of ions are generally found in any ionic compound?
Ans. Two—one type of cation and one type of anion. (Alums are an exception. They are composed of two different
cations and sulfate ions.)
9.2. Which of the following compounds are ionic? Which are soluble? Which would be written as separate
ions in an ionic equation as written for the first equation in this section? Write the species as they
would appear in an ionic equation. (a) CuCl, (b)NH 4 C 2 H 3 O 2 ,(c)Hg 2 Cl 2 ,(d) CoCl 2 ,(e)Na 3 PO 4 , and
(f)CH 3 OH(aq).

Written Formulas in Ionic
Ans. Ionic Soluble Separately Equation

(a) CuCl Yes No No CuCl
Yes Yes Yes + −
(b)NH 4 C 2 H 3 O 2 NH 4 + C 2 H 3 O 2
Yes No No
(c)Hg 2 Cl 2 Hg 2 Cl 2
Yes Yes Yes Co + 2Cl −
2+
(d) CoCl 2
Yes Yes Yes + 3−
(e)Na 3 PO 4 3Na + PO 4
(f)CH 3 OH(aq) No Yes No CH 3 OH
9.3. Write the formulas for the ions present in each of the following compounds: (a) NaClO 4 ,(b) BaCl 2 ,(c)
KClO, (d) Ba(NO 3 ) 2 ,(e) LiClO 3 ,(f) (NH 4 ) 3 PO 4 ,(g)Co 3 (PO 3 ) 2 ,(h) AgCl(s), and (i) Mg(HCO 3 ) 2 .
Ans. (a)Na and ClO 4 − (e) Li and ClO 3 − (h)Ag and Cl (even though it is
−
+
+
+
(b)Ba 2+ and Cl − (f ) NH 4 and PO 4 3− a solid)
+
+
(c) K and ClO − (g)Co 2+ and PO 3 3− (i) Mg 2+ and HCO 3 −
(d)Ba 2+ and NO 3 −
9.4. Write a net ionic equation for the equation in each of the following parts:
(a)NH 4 I + AgClO 3 −→ AgI(s) + NH 4 ClO 3
(b)H 2 SO 4 + BaCl 2 −→ BaSO 4 + 2 HCl
−
+
Ans. (a)I + Ag −→ AgI (b)SO 4 2− + Ba 2+ −→ BaSO 4
9.5. Write a net ionic equation for the equation in each of the following parts:
(a) HNO 3 + NaHCO 3 −→ NaNO 3 + CO 2 + H 2 O
(b) NaOH + NH 4 ClO 3 −→ NH 3 + H 2 O + NaClO 3
(c)HC 2 H 3 O 2 + KOH −→ KC 2 H 3 O 2 + H 2 O
(d) Ba(OH) 2 (aq) + 2H −→ BaI 2 + 2H 2 O

−
+
Ans. (a)H + HCO 3 −→ CO 2 + H 2 O (HNO 3 is strong)
+
−
(b)OH + NH 4 −→ NH 3 + H 2 O
(c)HC 2 H 3 O 2 + OH −→ C 2 H 3 O 2 + H 2 O (HC 2 H 3 O 2 is weak)
−
−
(d)OH + H −→ H 2 O
−
+
9.6. Given that BaCO 3 is insoluble in water and that NH 3 and H 2 O are covalent compounds, write net ionic
equations for the following processes:
(a)NH 4 Cl + NaOH −→ NH 3 + H 2 O + NaCl
(b) BaCl 2 + Li 2 CO 3 −→ BaCO 3 + 2 LiCl
+
−
Ans. (a)NH 4 + OH −→ NH 3 + H 2 O (b)Ba 2+ + CO 3 2− −→ BaCO 3