procedure Chemistry lab

procedure Chemistry lab Rinse and fill a 50 mL buret with standard 0.100 M sodium hydroxide (NaOH) solution. Pipet 25.00 mL of the “unknown” hydrochloric (HCl) solution into a 250 mL beaker containing a stir bar. Add about 50 mL of deionized water to the beaker. (The additional water is required to provide a solution volume sufficient to cover the pH electrode bulb in a subsequent titration. It is added here to ensure all titrations are carried out in the same manner.) Add 3 drops of phenolphthalein indicator. Gently stir the solution in the beaker using the magnetic stirrer. Read and record the initial buret reading to 2 decimal places. To prevent splashing, ensure the tip of the buret is below the top of the beaker. Slowly add NaOH from the buret. When a localized pink colour appears, slow the addition of NaOH to one drop at a time. The endpoint is a pale pink colour. When the solution turns pale pink (or dark pink if you overshoot) immediately stop the addition of NaOH. Allow the solution to settle in the buret for at least 30 seconds. Read and record the final buret reading. Also record the colour of your solution (light pink, medium pink, dark pink, etc).