Physical Chemistry Laboratory

CHAPTER 1

Introduction

1.1 Introduction to the Physical Chemistry Laboratory

The physical chemistry laboratory is intended to acquaint the students with the practice of experimental physical chemistry. Considerable effort has been made in linking the experiments with the topics of theory lectures.

Learning objectives: To familiarize the students with a number of the techniques to be used in laboratory. To give them some basis for judging the reliability of data. To develop the habit of keeping the laboratory record. To understand the interconnection between experimental foundation and underlying theoretical principles and to appreciate the limitations inherent in both theoretical treatments and experimental measurements. To gain familiarity

1.1) to be employed in the measurements are accurate and within the definite limits. The limit of accuracy is differing in the case of different instruments and apparatus. Since the apparatus for the determination of weight and of volume are those most generally concerned, in chemical or physico-chemical measurements, we shall first consider the methods of calibrating them. Determination of Weight

The determination of the mass or weight of a body is one of the most fundamental of physical measurements. In chemical analysis, the determination of weight of a body is not a matter of great difficulty for weighing about 100g with an accuracy of one part in one hundred thousand. Thus, in weighing glassware’s or other material, the difference in weight, due to the handling, the manner of drying the apparatus, etc., may sometimes amount to at least several tenths of a milligram, while the accuracy of the balance itself might quite well allow of the weight being determined to less than one-tenth of a

Fill the burette with water. Make sure the tip is free of bubbles. Drain into a waste beaker until it is at, or just below, the zero mark. Allow 10-20 seconds for drainage. Make an initial reading to a precision of at least 0.01ml. Test for tightness of the stopcock by allowing the burette to stand for 5 minutes and then re-reading the volume. There should be no noticeable change in the reading. Once the tightness of the stopcock is assured, refill the burette and again drain into a waste until it is at, or just below, the zero mark. Allow for drainage. Touch the tip of the burette to the wall of the waste beaker to remove the pendent drop of water. Make a volume