Instructions for Use
- Unscrew Cap.
- Extract the plug carefully. Use a firm grip to avoid dropping.
- Rinse inside and outside of the bottom part of the blind plug with 5-10mL of water while holding it over the beaker to capture the liquid.
- Pour entire contents of the Standardette® Solution into the beaker.
- Rinse the inside of the ampule 5 times with intermediate swirling into the beaker. Use 5- 10mL of water for each rinse.
- Top up volume in beaker to ~80mL with DI water.
- Add 1mL of 5% (aq) K2CrO4 Indicator Solution.
- Rinse a 50mL burette twice with about 10mL of AgNO3 solution.
- Clamp the burette in position and fill the burette to just above the zero mark with the
- < >Release any bubbles from the tip of the burette.
- Bring the AgNO3 solution meniscus down to or below the zero mark, read, and record the burette reading to the nearest 0.01mL.
- Note that although the Silver chloride that forms is a white precipitate, the Chromate indicator initially gives the cloudy solution a faint lemon-yellow color.
- Stir vigorously as the endpoint approaches, adding fractions of a drop of titrant using a glass stir rod.
- Stop at the endpoint of the titration which is the first appearance of a red-brown color of Silver chromate.
- Read the burette to the nearest 0.01mL.
- Complete the titration in exactly 3 minutes.
- Correct the volume of titrant to 20°C.
- Normality = Meq on the label /mL of Silver nitrate solution used