different ways. A buffer is a solution made of a weak acid and its conjugate base or a weak base and its conjugate acid. While the pH scale is from 0-14, from 0-6 the scale is acidic at the same time 8-14 is a base leading 7 alone to be a neutral value. Then comes conjugate acid-base pair consist of ions related by the loss of one H+by an acid, and the gain of H+by a base. And finally how to calculations for the first type of equation you use Kwto calculate [H3O+] and [OH-] in a solution in which the equation is Kw=[H3O+] [OH-] =1.0 x 10-14with 1.0 x 10-14 being either in the numerator or dominator. Secondly, calculating the pH from [H3O+] in which the equation is –log[H3O+] and lastly, calculation [H3O+] from pH by using [H3O+]=10-pH.Overall, learning about acid-base titration was interesting and these are a few things that attributed to it.
Introduction: Acid is a substance that increase the hydrogen ion concentration H+when dissolved in water. A base is a substance that increase the hydroxide ion concentration OH-when dissolved in water. When the acid and base are mix together it becomes a neutralization reaction which is water and salt. In this experiment an indicator will be present which is a water soluble dye which has one color for the acid and another for the base, with the indicator present it will determine the equivalence point with a color change. In the point at which the indicator changes color it is the end point of the titration. Titration is a technique used to determine the concentration of a solution using another solution with a known concentration. Procedure: 1. First the buret needs to be condition with the sodium hydroxide. To do this rotate the buret until the whole buret is cover all on the inside walls. Also, the stopcock on the buret needs to be conditions so open it so it the go through it and also its inner walls. 2. Then, fill the buret to the 0 mark so you could have exactly 50 mL of the sodium hydroxide in the buret 3. In an Erlenmeyer flask pipet 2 mL of vinegar, 2-3 drops of the phenolphthalein and 10 mL of distilled water 4. Now, open the stopcock and let the sodium hydroxide fall into the Erlenmeyer flask with the mixture till the buret hits 5-8 mL, you will start to see a flashing pink coming out the solution. Seeing this indicates you’re near the end point, yet keeping dripping the sodium hydroxide into the mixture until the mixture keeping a pale pink color. When this happens that is officially the end point. 5. Record the volume of the remaining sodium hydroxide and use it for the initial volume for trial 2 6. In the second trial clean out the Erlenmeyer flask and add 2 mL of vinegar, 2-3 drops of phenolphthalein, and 10 mL of distilled water 7. Begin to open the stopcock of the sodium hydroxide into the flask and when you see the flashing pink slow down the droplets of the sodium hydroxide while constantly stirring it until a pale pink holds it color 8. When a pale pink holds its color turn the stopcock on buret to the right to stop it, at this moment you have reached the end point of the second trail Data/ Calculation: Data Table: Known % acetic acid in vinegar: assume 4.7% AVERAGE NaOH volume (V b ) in mL: 17.55 mL Known Molarity of NaOH solution (read from container): .09583 M Trial 1 Trial 2 Trial 3: Trial 4: Volume of vinegar (must be precisely 2.00 mL each time): 2.00 mL 2.00 mL 2.00 mL 2.00 mL Initial volume reading of NaOH in the buret (0.00mL if full): 0.00 mL The initial volume for Trial 2 will be the final volume for Trial 1: 17.2 mL
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- Molarity, ml, Erlenmeyer flask