Acid Spill and Titration Notes

Acid Spill and Neutralization

Acid Dissociation

• Acids, like hydrochloric acid (HCl), dissociate completely in water.
• This dissociation produces hydrogen ions (H^+) and chloride ions (Cl^-).

Neutralization

• Acids can be neutralized by bases.
• Soluble bases are called alkalis (e.g., sodium hydroxide, NaOH).
• Alkalis also dissociate completely in water, producing sodium ions (Na^+) and hydroxide ions (OH^-).

Acid-Base Reaction

• Acids and alkalis react to form a salt and water.
• Example: Sodium hydroxide (NaOH) + Hydrochloric acid (HCl) → Sodium chloride (NaCl) + Water (H_2O).

Net Ionic Equation

• Spectator ions (ions that appear on both sides of the equation) can be removed to simplify the equation.
• Net ionic equation: H^+ (aq) + OH^- (aq) → H_2O (l).

Concentration

• Concentration measures the amount of a substance dissolved in a volume.
• Measured in moles per cubic decimeter (mol/dm³).

Titration

• Titration is performed to determine the concentration of hydrogen ions in an acid solution.
• Acid is added to the alkali until all of the alkali has reacted (neutralization point).
• pH is neutral at the end point.
• An indicator compound is used to detect the neutralization point by changing color.

Titration Calculation Example

• Balanced equation: 1 mole HCl reacts with 1 mole NaOH.
• Amount of alkali is calculated using the known concentration and volume of the alkali solution.
• Volume of acid reacted is read from the burette.
• Repeat titration to calculate the average volume of acid added.
• Rearrange the equation to calculate the unknown concentration of acid.

Environmental Response Scenario

• Environmental response team assesses the impact of an acid spill and advises on an appropriate response.
• Samples from the contaminated river are collected for testing.
• Titration experiment is used to calculate the concentrations of acid in the samples.
• Objective: Carefully add the right amount of acid to the alkali solution to the neutralization point, indicated by the color change of the indicator.