Calculating the Concentration of Sodium Hydroxide Solution Using Titration

Introduction

In a laboratory, 150L of caustic soda are to be neutralized, but the concentration of the lye is unknown. An employee takes a 30ml sample of the caustic soda and titrates it with 1 mol/L hydrochloric acid to the neutral point (7). The worker requires 45ml of hydrochloric acid for 30ml of sodium hydroxide solution. Let's calculate the concentration of the sodium hydroxide solution and determine the volume of hydrochloric acid needed to neutralize the entire amount of sodium hydroxide solution.

Calculation

Concentration of Sodium Hydroxide Solution: The concentration of the sodium hydroxide (NaOH) solution given its neutralization by hydrogen chloride (HCl) is 1.5 M.

Volume of Hydrochloric Acid Needed: The volume of 1 M HCl required to neutralize the total 150 L of NaOH is 225 L.

Explanation

The concentration of the sodium hydroxide solution is calculated using a titration method. In the given chemical reaction, HCl reacts with NaOH to create a neutral solution, having a pH of 7. Following the balanced chemical equation, HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq), the molar amounts for the neutralization are equal due to the stoichiometry of the reaction.

Using the molarity formula M = moles/volume, the molarity of the NaOH solution is determined to be 1.5 M. To find the total volume of HCl needed for the 150 L of NaOH, the concentration of NaOH (1.5 M) is multiplied by the total volume (150 L) to obtain 225 L of HCl.

Question:

What is the concentration of the sodium hydroxide solution and the volume of hydrochloric acid needed for neutralization in this titration?

Answer:

The concentration of the sodium hydroxide (NaOH) solution given its neutralization by hydrogen chloride (HCl) is 1.5 M. The corresponding volume of 1 M HCl required to neutralize the total 150 L of NaOH is 225 L.

Explanation: The concentration of the sodium hydroxide solution is calculated using a titration method. In the given chemical reaction, HCl (hydrochloric acid) reacts with NaOH (sodium hydroxide) to create a neutral solution, having a pH = 7.00. The balanced chemical equation is HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq). Here, 45 ml of 1 M HCl solution is needed to neutralize 30 ml of sodium hydroxide solution, indicating that their molar amounts are equal in the reaction due to the ratio in the balanced equation."}