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Neutralization Reaction. Base and acid react to produce a salt and water. Titration. A lab technique where a neutralization reaction is preformed to determine the concentration of an unknown. The anatomy of a titration:. Standard solution - solution of known concentration.
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Neutralization Reaction • Base and acid react to produce a salt and water
Titration • A lab technique where a neutralization reaction is preformed to determine the concentration of an unknown.
The anatomy of a titration: • Standard solution - solution of known concentration. • End Point - the point at which neutralization is achieved • Indicator - chemical that changes color with a change in pH. We will be using phenolphthalein. Clear in an acid pink in a base You want a light pink • Buret - Measurement device
Titration Calculations4 steps • Start with the balanced equation • Find the moles in the standard solution • Set up ratio to find moles of unknown • Find molarity(mol/L) or volume
Titration Calculations example problem • A 25.75 ml solution of H2SO4 is neutralized by 18.23 ml of 1.0 M NaOH. What is the concentration of H2SO4? • H2SO4 + 2 NaOH --> Na2SO4 + 2 H2O • 0.01823 L NaOH 1.0 mol NaOH 1 mol H2SO4 1 L NaOH 2 mol NaOH 0.02575L H2SO4 • = 0.35 mol/L H2SO4
Titration Problemsyour turn • What is the molarity of phosphoric acid if 15.0 mL of the solution is neutralized by 8.5 mL of 0.15 M NaOH? • H3PO4 + 3 NaOH --> Na3PO4 + 3 H2O • 0.0085 L NaOH 0.15 mol NaOH 1 mol H3PO4 1 L NaOH 3 mol NaOH 0.0150 L H3PO4 = 0.028 mol/L H3PO4
Titration Problems1 more your turn • How many milliliters of 0.45 M hydrochloric acid must be added to 25.0 mL of 0.15 M NaOH? • HCl + NaOH --> NaCl + H2O • 0.0250 L NaOH 0.15 mol NaOH 1 mol HCl 1L HCl 1000 mL 1 L NaOH 1 mol NaOH 0.45 mol HCl 1L = 8.3 mL HCl