Here's a typical titration problem. Hydroiodic acid is being standardized with the sodium hydroxide solution. Standardizing means nothing more than to determine accurately the concentration of a solution. So 24.9 nils of hydroiodic acid is to be standardized with sodium hydroxide. This thing is make sure you have a balanced chemical equation that accurately reflects the titration. This case, hydroiodic acid reacts with sodium hydroxide and it's a 1 to 1 ratio. I included this illustration just to remind you of what goes on during a titration. A buret is clamped to a stand and an urlemire flask is placed below the buret. The buret usually contains the solution with known concentration and the urlemire flask holds the other reactant, typically of unknown concentration. So in this case, the sodium hydroxide is in the buret and the hydroiodic acid solution is in the urlemire flask and the reaction occurs in the urlemire flask. The first step is to calculate the moles of sodium hydroxide used. To do this, multiply the molarity of the sodium hydroxide 0.185 by the volume of sodium hydroxide used. This case 0.0249 liters giving you 0.00461 moles of base which is the same as the moles of acid in the urlemire flask. Then calculate the molarity of the hydroiodic acid solution. It's important that you use the original volume of the hydroiodic acid solution. In this case, 0.00461 moles divided by 0.0249 liters which gives you 0.15 molar hydroiodic acid. If you think about the volume used and the fact that it's a 1 to 1 ratio, it should come as no surprise that the concentration of the hydroiodic acid solution is the same as the sodium hydroxide solution. Here's a slight variation on the previous problem. Rather than having equal amounts of acid and base in the standardization problem, here we have 26 mils of acid being standardized with 24.9 mils of base. What I would like for you to do is predict if the concentration of the acid will be greater than or less than 0.185 molar, knowing that there's a 1 to 1 ratio between the acid and the base. If you predicted less, you would be correct. This is another type of standardization problem. Rather than using a solution to standardize another solution, we're using a solid. KHP, as it's typically abbreviated, or potassium hydrogen thali, is a common substance used to standardize, is a common weak acid used to standardize strong bases. As always, it's always important first to understand the chemistry and the titration. In this case, we're abbreviating potassium hydrogen thali as KHP. Notice the 2 to 1 stoichiometry between the KHP and the strong base. In this case, the known amount of KHP is in the Erlemire flask, dissolved in some arbitrary amount of water, and the barium hydroxide solution is in the VRET. One way to approach problems like this is to consider the final calculation. You're going to need to determine some amount of barium hydroxide in moles and divide that by the total amount of barium hydroxide used in the titration. In this case, it was 27.7 milliliters. That was in the previous examples. First calculate the moles of the reactant of which you have either accurate molarity or accurate mass measurement. So 0.190 grams of KHP divided by 24 grams per mole of KHP gives 0.00446 moles of KHP. So knowing the 2 to 1 ratio between KHP and barium hydroxide, realize that 0.00223 moles of barium hydroxide would react if 0.00446 moles of KHP are in the solution. And finally, carry out the calculation that was proposed earlier. This case, we have 0.00223 moles of barium hydroxide and divide that by the volume of barium hydroxide used.