Acid-base titrations

             Concentration of NaOH 0.5 mol/L.
             0.5 mol/L 0.5 mol/L .
             Final reading of base buret 41.1 mL.
             41.1 mL 41.1 mL .
             Initial reading of base buret 0 Mark.
             0 Mark 0 Mark .
             Volume of NaOH used 41.1 mL.
             0411L 41.1 mL.
             0411 L 41.1 mL.
             0411 L .
             Final reading of acid buret 20 mL.
             40 mL 10 mL .
             Initial reading of acid buret 0 Mark.
             0 Mark 0 Mark .
             Volume of HCL used 20 mL.
             02 L 20 mL.
             02 L 20 mL.
             02 L .
             Moles of NaOH used 0.0209 mol.
             0.0209 mol 0.0209 mol .
             Moles of HCL used 0.0209 mol.
             0.0209 mol 0.0209 mol .
             Concentration of HCL 1.045 mol/L.
             1.045 mol/L 1.045 mol/L .
             2. Obtain about 120 mL of hydrochloric acid solution in a 250 mL beaker. Label the beaker. Rinse a buret with about 10 mL of the sloution, and let the liquid drain through the buret tip into an empty 250 mL beaker. Repeat this procedure twice more. Refill the buret so that the meniscus of the solution is above the zero mark. Position the buret in a double buret clamp on a ring stand. Let some of the solution run rapidly from the buret to expell all air bubbles from the tip and bring the level of the solution down to the calibrated region of the buret. If there is a drop of solution hanging on the buret tip,remove it by touching the drop to the inside wall of the 250 mL beaker. Hold a piece of white paper behind the meniscus, and read the initial volume of the solution at the bottom of the meniscus. Your eye must be at the same level as the meniscus.
             3. Obtain about 120 mL of the sodium hydroxide in a second labelled 250 mL beaker. Obtain a second buret and repeat part 2.
             4. Let about 20 mL of hydrocholric acid flow from the acid buret into a clean 250 mL Erlenmeyer flask. Add 2 drops of phenolphthalein. Place the Erlenmeyer flask under the tip of the base buret. A piece of white paper placed under the flask will make it easier to see the colour changes. While continuously swirling the flask to ensure thorough mixing, run in the sodium hydroxide solution from the buret.