Question #2e6ba

1 Answer
Sep 1, 2015

Hydrochloric acid, #"HCl"#.

Explanation:

Sodium hydroxide is a strong base, which means that it will exist as sodium cations, #"Na"^(+)#, and hydroxide anions, #"OH"^(-)#, in aqueous solution.

In order to produce sodium chloride, #"NaCl"#, which is a soluble salt that exists as sodium ations and chloride anions, #"Cl"^(-)# in aqueous solution, you need to provide the sodium hydroxide solution with two things

  • Hydrogen ions, or protons, #"H"^(+)#, to neutralize the hydroxide ions;
  • chloride ions, #"Cl^(-)#.

This implies that you in order for the reaction to produce sodium chloride, you need a strong acid that dissociates into hydrogen ions and chloride ions in solution.

Hydrochloric acid, #"HCl"#, does just that. When you mix these two solutions in a #1:1# mole ratio, the hydrogen ions will react with the hydroxide ions to produce water, leaving you with dissolved sodium chloride.

#"NaOH"_text((aq]) + "HCl"_text((aq]) -> "NaCl"_text((aq]) + "H"_2"O"_text((l])#

This reaction is called a neutralization reaction because you use an acid to neutralize a base, leaving the solution at a neutral pH afterwards.