Na2CO3(aq) + 2HCl(aq) → 2NaCl(aq) + H2O(l) + CO2(g)
Since sodium carbonate is a primary standard, it is widely used for the accurate determination of the concentration of HCl solutions. To perform the titration, a known mass of sodium carbonate is precisely weighed and dissolved in water. The resulting solution is then slowly added to the HCl solution while constantly stirring until the endpoint is reached.
The endpoint of the titration is determined using an indicator, which changes color in response to the pH change. A commonly used indicator for the titration of HCl with sodium carbonate is methyl orange, which turns from red to yellow as the pH of the solution increases. The equivalence point is reached when the amount of sodium carbonate added is stoichiometrically equivalent to the amount of HCl present in the solution.
By carefully recording the volume of HCl required to reach the equivalence point, the exact concentration of the HCl solution can be accurately calculated. This titration method is reliable, precise, and can provide accurate results for determining the concentration of HCl solutions in various analytical and laboratory settings.
