Using the steps above, a solution of sodium carbonate reacts with a solution of sulphuric acid to produce sodium sulphate, carbon dioxide, and water.
a. Write the ionic equation for this reaction.
b. Identify the spectator ions in this reaction.
Balance the equation below and write its ionic equation.
[tex]CaCO_3(s)+HCl(aq) \longrightarrow CaCl_2(aq)+CO_2(g)+H_2 O(l)[/tex]
Answer (1)
Write the balanced molecular equation for the reaction between sodium carbonate and sulfuric acid: N a 2 C O 3 ( a q ) + H 2 S O 4 ( a q ) ⟶ N a 2 S O 4 ( a q ) + C O 2 ( g ) + H 2 O ( l ) .
Write the complete ionic equation: 2 N a + ( a q ) + C O 3 2 − ( a q ) + 2 H + ( a q ) + S O 4 2 − ( a q ) ⟶ 2 N a + ( a q ) + S O 4 2 − ( a q ) + C O 2 ( g ) + H 2 O ( l ) .
Identify and remove spectator ions ( N a + and S O 4 2 − ) to obtain the net ionic equation: C O 3 2 − ( a q ) + 2 H + ( a q ) ⟶ C O 2 ( g ) + H 2 O ( l ) .
Balance the second equation and write its net ionic equation: C a C O 3 ( s ) + 2 H + ( a q ) ⟶ C a 2 + ( a q ) + C O 2 ( g ) + H 2 O ( l ) .
Explanation
Problem Analysis Let's start by analyzing the reaction between sodium carbonate and sulfuric acid. We need to write the balanced molecular equation, then the complete ionic equation, and finally identify and remove the spectator ions to get the net ionic equation. For the second part, we'll balance the calcium carbonate reaction and do the same ionic equation process.
Balanced Molecular Equation The balanced molecular equation for the reaction between sodium carbonate ( N a 2 C O 3 ) and sulfuric acid ( H 2 S O 4 ) is: N a 2 C O 3 ( a q ) + H 2 S O 4 ( a q ) ⟶ N a 2 S O 4 ( a q ) + C O 2 ( g ) + H 2 O ( l )
Complete Ionic Equation Now, let's write the complete ionic equation by dissociating all the aqueous species into ions: 2 N a + ( a q ) + C O 3 2 − ( a q ) + 2 H + ( a q ) + S O 4 2 − ( a q ) ⟶ 2 N a + ( a q ) + S O 4 2 − ( a q ) + C O 2 ( g ) + H 2 O ( l )
Identifying Spectator Ions Next, we identify the spectator ions. These are the ions that appear unchanged on both sides of the equation. In this case, the spectator ions are sodium ions ( N a + ) and sulfate ions ( S O 4 2 − ).
Net Ionic Equation Finally, we write the net ionic equation by removing the spectator ions from the complete ionic equation: C O 3 2 − ( a q ) + 2 H + ( a q ) ⟶ C O 2 ( g ) + H 2 O ( l )
Balancing the Second Equation Now, let's balance the second equation: C a C O 3 ( s ) + H Cl ( a q ) ⟶ C a C l 2 ( a q ) + C O 2 ( g ) + H 2 O ( l ) To balance this equation, we need two molecules of H Cl :
C a C O 3 ( s ) + 2 H Cl ( a q ) ⟶ C a C l 2 ( a q ) + C O 2 ( g ) + H 2 O ( l )
Complete Ionic Equation for the Second Reaction Now, we write the complete ionic equation for the balanced reaction: C a C O 3 ( s ) + 2 H + ( a q ) + 2 C l − ( a q ) ⟶ C a 2 + ( a q ) + 2 C l − ( a q ) + C O 2 ( g ) + H 2 O ( l )
Net Ionic Equation for the Second Reaction The spectator ion in this reaction is the chloride ion ( C l − ). Removing the spectator ion gives us the net ionic equation: C a C O 3 ( s ) + 2 H + ( a q ) ⟶ C a 2 + ( a q ) + C O 2 ( g ) + H 2 O ( l )
Final Answer In summary, for the first reaction, the net ionic equation is: C O 3 2 − ( a q ) + 2 H + ( a q ) ⟶ C O 2 ( g ) + H 2 O ( l ) and the spectator ions are N a + and S O 4 2 − .
For the second reaction, the balanced equation is: C a C O 3 ( s ) + 2 H Cl ( a q ) ⟶ C a C l 2 ( a q ) + C O 2 ( g ) + H 2 O ( l ) the net ionic equation is: C a C O 3 ( s ) + 2 H + ( a q ) ⟶ C a 2 + ( a q ) + C O 2 ( g ) + H 2 O ( l ) and the spectator ion is C l − .
Examples
Understanding ionic equations is crucial in many real-world applications. For instance, in wastewater treatment, we use chemical reactions to remove pollutants. Knowing the net ionic equation helps us focus on the actual reacting species and design more efficient treatment processes. Similarly, in environmental science, understanding these reactions helps us predict the impact of acid rain on natural resources like limestone formations, which primarily consist of calcium carbonate. The reaction between acid rain (containing sulfuric acid) and limestone can be represented by ionic equations, allowing us to assess and mitigate the damage.
