Titration notes and practice

Titrations To determine the concentration for a particular solute in a solution, chemists often carry out a titration , which involves combining a sample of the solution with a reagent solution of known concentration, called a standard solution . We will be titrating acids and bases together to the equivalence point to determine information about one of the reactants. The equivalence is the point at which the added solute reacts completely with the solute present in the solution. For acid/base reactions when all the [H + ] react consume all the [OH - ]. An indicator is used to show the equivalence point during a titration. The point when the indicator changes color, is called the endpoint . A titration involves the progressive addition of one reactant from a burette to a known volume of the other reactant in an Erlenmeyer flask. Let’s first remind ourselves of the math. Example: 1. 25.00 mL of a 0.100 M HBr solution is titrated with a 0.200 M NaOH. How many mL of NaOH solution are required to reach the equivalence point? 2. 25.0 mL of 1.50 M LiOH are neutralized by 15.0 mL of nitric acid. What is the molarity of HNO 3 ? 3. 50.0 mL of an unknown solution of Ca(OH) 2 are titrated with 0.15 M HCl. Find the molarity of the Ca(OH) 2 solution if 83 mL of acid are required to reach the equivalence point. 4. What volume of 0.083 M H 3 PO 4 is required to neutralize 30.0 cm 3 of 0.025 M Ba(OH) 2 ? 5. What is the molarity of a NaOH solution if 25.00 cm 3 is required to completely neutralize 40.00 cm 3 of a 1.50 M solution of Sulfuric Acid? 6. Calculate the cm 3 of a 0.600 M solution of nitric acid necessary to neutralize 28.55 cm 3 of a 0.450 M solution of potassium hydroxide. 7. A titration of 15.00 cm 3 of household ammonia NH 3 , required 38.57 cm 3 of a 0.780 M Hydrochloric acid . Calculate the Molarity of the Ammonia.