Chemistry Lab Report 2
Menbere Wendimu
Che101
Laboratory Report
Acid Base Laboratory
Objective:
Introduction:
Experimental:
2.04 g of KHP, 100ml volumetric flask, distilled H2O, approximately 0.1 M of NaOH, Vinegar, Phenolphthalein, 250ml Erlenmeyer flask, weighing balance, Graduating Cylinder, burette and pH meter were used in our experiment.
In our first part of our experiment to prepare a primary standard, 0.1 M solution of KHP, we carefully weighed out 2.04g of KHP in a weigh paper using the weighing balance and transferred the measured KHP into a 100ml volumetric flask. We rinsed the weigh boat with distilled H2O to make sure that all the measured KHP is transferred into the flask and added distilled H2O into the flask until the meniscus of the water touches the line of the flask. We did not measure the amount of H2O added since water doesn’t involve in the reaction. We then swirled and inverted the flask until all the KHP is dissolved into the H2O.
KHP+H2O-------H3O+ + KP-
In our second part of our experiment to determine the molarity of NaOH, we rinsed a burette with about 5ml of water and another 5ml of NaOH to prepare it for the experiment. We then measured exactly 25ml of the prepared KHP from the previous part into a 250ml Erlenmeyer flask and added 2 drops of the indicator, phenolphthalein. Next we filled the burette with the approximately 0.1 M NaOH so that our initial volume will be 0.0mls. We then started our titration by carefully pouring a little amount of the base into the prepared 25ml of KHP with phenolphthalein until we reached the end point. Since the molarity of the NaOH was designed to be more or less the same with the acid, we knew that it would take equal amount of the base to reach the endpoint. Thus we added the first 20 mls in about 5ml increment and swirled to mix after each addition then added just 6-7 drops for the next mls. After we started observing a pink color, we started adding just 2 drops at a time and swirl the flask. When we
Che101
Laboratory Report
Acid Base Laboratory
Objective:
Introduction:
Experimental:
2.04 g of KHP, 100ml volumetric flask, distilled H2O, approximately 0.1 M of NaOH, Vinegar, Phenolphthalein, 250ml Erlenmeyer flask, weighing balance, Graduating Cylinder, burette and pH meter were used in our experiment.
In our first part of our experiment to prepare a primary standard, 0.1 M solution of KHP, we carefully weighed out 2.04g of KHP in a weigh paper using the weighing balance and transferred the measured KHP into a 100ml volumetric flask. We rinsed the weigh boat with distilled H2O to make sure that all the measured KHP is transferred into the flask and added distilled H2O into the flask until the meniscus of the water touches the line of the flask. We did not measure the amount of H2O added since water doesn’t involve in the reaction. We then swirled and inverted the flask until all the KHP is dissolved into the H2O.
KHP+H2O-------H3O+ + KP-
In our second part of our experiment to determine the molarity of NaOH, we rinsed a burette with about 5ml of water and another 5ml of NaOH to prepare it for the experiment. We then measured exactly 25ml of the prepared KHP from the previous part into a 250ml Erlenmeyer flask and added 2 drops of the indicator, phenolphthalein. Next we filled the burette with the approximately 0.1 M NaOH so that our initial volume will be 0.0mls. We then started our titration by carefully pouring a little amount of the base into the prepared 25ml of KHP with phenolphthalein until we reached the end point. Since the molarity of the NaOH was designed to be more or less the same with the acid, we knew that it would take equal amount of the base to reach the endpoint. Thus we added the first 20 mls in about 5ml increment and swirled to mix after each addition then added just 6-7 drops for the next mls. After we started observing a pink color, we started adding just 2 drops at a time and swirl the flask. When we