Acid Base Titration Titration the progressive addition of
Acid – Base Titration
Titration: the progressive addition of a base to an acid or an acid to a base. It is a volumetric method of analysis used to find the concentration of an acid or base. Na. OH + HCl H 2 O + Na. Cl (titration is a neutralization reaction) Endpoint: the point when the indicator colour changes (usually at the end of the titration) Equivalence point: The point when the number of equivalents mixed together are the same (in acid-base titrations equivalents refer to the number of moles of H+ and OH–)
Titration Formula #H x MA x VA = #OH x MB x VB MA = concentration of acid MB= concentration of base VA = volume of acid VB = volume of base #H = the number of H’s in the acid #OH = the number of OH’s in the base
Titration problems • What volume of 0. 10 mol/L Na. OH is needed to neutralize 25. 0 m. L of 0. 15 mol/L H 3 PO 4? • 25. 0 m. L of HCl(aq) was neutralized by 40. 0 m. L of 0. 10 mol/L Ca(OH)2 solution. What was the concentration of HCl? • A truck carrying sulfuric acid is in an accident. A laboratory analyzes a sample of the spilled acid and finds that 20 m. L of acid is neutralized by 60 m. L of 4. 0 mol/L Na. OH solution. What is the concentration of the acid?
Titration problems 1. (3)(0. 15 M)(25 m. L) = (1)(0. 10 M)(VB) VB= (3)(0. 15 M)(25 m. L) / (1)(0. 10 M) = 112. 5 m. L 2. (1)(MA)(25 m. L) = (2)(0. 10 M)(40 m. L) MA= (2)(0. 10 M)(40 m. L) / (1)( 25 m. L) = 0. 32 M 3. Sulfuric acid = H 2 SO 4 (2)(MA)(20 m. L) = (1)(4. 0 mol/L)(60 m. L) MA = (1)(4. 0 M)(60 m. L) / (2)(20 m. L) = 6. 0 M
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