Fill in the name and empirical formula of each ionic compound that could be formed from the ions in this table:
| cation | anion | empirical formula | name of compound |
|---|---|---|---|
| [tex]Pb ^{2+}[/tex] | [tex]C _2 H _3 O _2^{-}[/tex] | | |
| [tex]Ca ^{2+}[/tex] | [tex]NO _3^{-}[/tex] | | |
| [tex]K ^{+}[/tex] | [tex]CH _3 CO _2^{-}[/tex] | | |
Answer (1)
Balance the charges of P b 2 + and C 2 H 3 O 2 − to get the empirical formula P b ( C 2 H 3 O 2 ) 2 and name lead(II) acetate.
Balance the charges of C a 2 + and N O 3 − to get the empirical formula C a ( N O 3 ) 2 and name calcium nitrate.
Balance the charges of K + and C H 3 C O 2 − to get the empirical formula K C H 3 C O 2 and name potassium acetate.
The empirical formulas and names of the ionic compounds are: P b ( C 2 H 3 O 2 ) 2 - lead(II) acetate, C a ( N O 3 ) 2 - calcium nitrate, and K C H 3 C O 2 - potassium acetate.
Explanation
Problem Analysis We are given a table with cations and anions and asked to determine the empirical formula and name of the ionic compound formed by each cation-anion pair. We need to balance the charges of the ions to determine the correct subscripts for the empirical formula and then name the compound accordingly.
Lead(II) Acetate For P b 2 + and C 2 H 3 O 2 − :
The lead(II) ion has a +2 charge, and the acetate ion has a -1 charge. To balance the charges, we need two acetate ions for each lead(II) ion. Thus, the empirical formula is P b ( C 2 H 3 O 2 ) 2 . The name of the compound is lead(II) acetate.
Calcium Nitrate For C a 2 + and N O 3 − :
The calcium ion has a +2 charge, and the nitrate ion has a -1 charge. To balance the charges, we need two nitrate ions for each calcium ion. Thus, the empirical formula is C a ( N O 3 ) 2 . The name of the compound is calcium nitrate.
Potassium Acetate For K + and C H 3 C O 2 − :
The potassium ion has a +1 charge, and the acetate ion has a -1 charge. The charges are already balanced, so we need one of each ion. Thus, the empirical formula is K C H 3 C O 2 . The name of the compound is potassium acetate.
Final Answer Therefore, the completed table is:
cation
anion
empirical formula
name of compound
P b 2 +
C 2 H 3 O 2 −
P b ( C 2 H 3 O 2 ) 2
lead(II) acetate
C a 2 +
N O 3 −
C a ( N O 3 ) 2
calcium nitrate
K +
C H 3 C O 2 −
K C H 3 C O 2
potassium acetate
Examples
Ionic compounds are prevalent in everyday life. For instance, sodium chloride (NaCl), or table salt, is used to season food. Calcium carbonate (CaCO3) is found in antacids to neutralize stomach acid. Understanding how these compounds are formed and named helps us recognize and utilize them effectively in various applications.
