HCl (aq) and NaOH (aq)
Answer (2)
The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) produces sodium chloride (NaCl) and water (H2O) through a neutralization process. The molecular equation is HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l), while the net ionic equation simplifies to H+(aq) + OH−(aq) → H2O(l). Understanding this reaction highlights key concepts in acid-base chemistry.
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The molecular equation is: H Cl ( a q ) + N a O H ( a q ) → N a Cl ( a q ) + H 2 O ( l ) .
The complete ionic equation is: H + ( a q ) + C l − ( a q ) + N a + ( a q ) + O H − ( a q ) → N a + ( a q ) + C l − ( a q ) + H 2 O ( l ) .
The net ionic equation is: H + ( a q ) + O H − ( a q ) → H 2 O ( l ) .
The reaction represents the neutralization of a strong acid by a strong base, forming water and a salt.
Explanation
Introduction to the Reaction The reaction between hydrochloric acid ( H Cl ) and sodium hydroxide ( N a O H ) is a classic acid-base neutralization reaction. Our goal is to write the molecular, complete ionic, and net ionic equations for this reaction.
Molecular Equation First, we write the balanced molecular equation. H Cl ( a q ) reacts with N a O H ( a q ) to produce sodium chloride ( N a Cl ) and water ( H 2 O ). The balanced molecular equation is: H Cl ( a q ) + N a O H ( a q ) → N a Cl ( a q ) + H 2 O ( l )
Complete Ionic Equation Next, we write the complete ionic equation. Strong electrolytes such as H Cl , N a O H , and N a Cl dissociate completely into their ions in aqueous solution. Water, being a liquid, remains in its molecular form. The complete ionic equation is: H + ( a q ) + C l − ( a q ) + N a + ( a q ) + O H − ( a q ) → N a + ( a q ) + C l − ( a q ) + H 2 O ( l )
Net Ionic Equation Now, we identify and cancel out the spectator ions, which are the ions that appear on both sides of the equation. In this case, N a + ( a q ) and C l − ( a q ) are spectator ions. After canceling them out, we obtain the net ionic equation: H + ( a q ) + O H − ( a q ) → H 2 O ( l )
Final Equations Therefore, the molecular equation is: H Cl ( a q ) + N a O H ( a q ) → N a Cl ( a q ) + H 2 O ( l ) The complete ionic equation is: H + ( a q ) + C l − ( a q ) + N a + ( a q ) + O H − ( a q ) → N a + ( a q ) + C l − ( a q ) + H 2 O ( l ) And the net ionic equation is: H + ( a q ) + O H − ( a q ) → H 2 O ( l )
Examples
Acid-base reactions are fundamental in many real-world applications. For example, antacids use neutralization reactions to relieve heartburn by reacting with excess stomach acid ( H Cl ). Similarly, in chemical manufacturing, controlling pH through acid-base reactions is crucial for producing various products, from pharmaceuticals to detergents. Understanding these reactions helps us manage acidity levels in different processes and environments.
