when sulfuric acid is added to solid sodium chloride and the mixture is heated, hydrogen chloride gas is generated, leaving a solid residue of sodium sulfate
See your post above.
When sulfuric acid (H2SO4) is added to solid sodium chloride (NaCl) and heated, a chemical reaction occurs. The reaction can be represented as follows:
2NaCl + H2SO4 -> 2HCl + Na2SO4
In this reaction, the sulfuric acid reacts with sodium chloride to produce hydrogen chloride gas (HCl) and sodium sulfate (Na2SO4) as a solid residue.
To understand why this reaction occurs, let's break it down step by step:
1. Dissociation of sulfuric acid: When sulfuric acid is dissolved in water or reacts with a solid compound like sodium chloride, it dissociates into ions. Sulfuric acid dissociates into two hydrogen ions (H+) and one sulfate ion (SO4^2-).
H2SO4 -> 2H+ + SO4^2-
2. Dissociation of sodium chloride: Solid sodium chloride is made up of sodium ions (Na+) and chloride ions (Cl-). When sodium chloride is dissolved or reacts with another compound, it dissociates into these ions.
NaCl -> Na+ + Cl-
3. Reaction between hydrogen ions and chloride ions: The hydrogen ions from the sulfuric acid react with the chloride ions from sodium chloride to form hydrogen chloride gas.
2H+ + 2Cl- -> 2HCl
4. Formation of sodium sulfate: The remaining sulfate ions from the sulfuric acid react with the sodium ions, forming solid sodium sulfate.
Na+ + SO4^2- -> Na2SO4
This reaction is known as an acid-base or neutralization reaction because the hydrogen ions from the acid combine with the chloride ions from the base (sodium chloride) to form hydrogen chloride.
It's important to note that this reaction is accompanied by the release of heat, hence why heating is mentioned in your question. The hydrogen chloride gas generated can be collected, and the solid sodium sulfate residue remains.
In summary, when sulfuric acid is added to solid sodium chloride and heated, hydrogen chloride gas is generated, while solid sodium sulfate is produced as a residue.