Tadayosi Yoshimura*1, Hideo Sakagami*1, Yoshihiro Fujikami*2 and Brian T. Newbold*3
No. chapter title
1 neutralization heat between acid and base solutions 2 dilution heat of dimethylformamide into water 3 molecular weight of acetone by Victor-Meyer method 4 molecular weight of nitrobenzene by steam distillation method 5 molecular weight of naphthalene by depression of freezing point method 6 solubility of benzoic acid and the dissolution heat 7 partition coefficient between aqueous and tetrachloromethane phases 8 ionization constant of acetic acid 9 physical properties (viscosity, density etc.) of ethanol and water solution 10 hydrolysis of ethyl acetate in acidic solution 11 hydrolysis of ethyl acetate in basic solution 12 inversion reaction of sucrose solution 13 adsorption of acetic acid on activated charcoal 14 point of zero charge of metal oxide colloid 15 electromotive force of concentration cell 16 decomposition voltage of electrolyte solutions 17 transport number of HCl solution 18 potential difference titration of neutralization
The student must understand the experimental operation necessary for training beforehand in each theme. In order to develop CAL, we have prepared three softwares: Japanese word processor, graphic processor, and building shell system[4,5]. Incidentally, the CAL software is made perfectly and easily for the desired physical chemistry experiment courseware. These softwares cover the l8 chapters mentioned above and each one consists of four sections:
l) theory and principle, 2) experimental (apparatus and device), 3) experimental operation, 4) result and discussion.
Each section has one or two questions as a drill. The student not only learns physical chemistry unilaterally, but also answers a question. He/she will understand an experimental subject through beforehand learning. Figures l, 2, 3, and 4 show samples of the CAL display of chapter 5 (molecular weight of naphthalene by depression of freezing point method). These hardcopies are made by photocopying, so they show up in black and white. In reality, the displays are in beautiful color. This CAL software is made up of two frames: explanation frame and drill frame. For example, the display in Figure l is section 2, which illustrates the diagrammatic representation of a Beckmann thermometer operation. Figure 2 shows an example of a drill frame. Question 5.2 of Figure 2 is the key point for use of the thermometer. Figure 3 shows an example of the experimental operation. The experimental result is explained in a graphic way as seen in Figure 4.
These CAL softwares for physical chemistry experiments are now distributed free to members of the Chemical Software Society of Japan. They are available any time and are very useful for individual learning.
Figure 1. Display of section 2 in chapter 5.
[Explanation] This diagrammatic representation is a Beckmann thermometer operation. The thermometer has to be used carefully when measuring minute change of temperature in a calorimeter box.
Figure 2. Display of drill frame in chapter 5.
[Explanation] This drill frame (question 5.2) is for operating a Beckmann thermometer. The key point is selected exactly among three operation terms.
Figure 3. Display of section 3 in chapter 5.
[Explanation] This diagrammatic representation is the experimental operation of depression of freezing point method. The refrigerants are ice and salt.
Figure 4. Display of section 4 in chapter 5.
[Explanation] The experimental result is explained in a graphic way. The depression degree .Delta.Tf is determined from this figure.
Figure 5. Flow scheme for practical experiment with beforehand learning by texbook (report A) or CAL (report B).
Figure 6. Histogram of the score improvement with or without the CAL softwares.
A : students obtained less marks than the mean score, B : students had better marks than the mean score.
In order to study the educational effect with or without CAL software, we have examined the improvement rate for the student's score. The result is shown in Figure 6. A vertical line in the histogram is a score improvement with or without CAL softwares, which is defined as the score value with CAL software divided by that without CAL software. Thus, if a student gets 8 points per l0 full mark with software and obtains 6 points without software, the score improvement is l.3. The value of the histogram means the % number of students. The left side of the histogram describes the score improvement of students who got less marks and the right side that of those who had better marks than the mean score. It is found that the CAL effect is weak for the lazy student who does not intend to run experimental training, though the score improvement is taken in general from group A in Figure 6. Compared with group A, a student in group B gets better marks with CAL software than one without it, and the score improvement rate concentrates on a histogram of l.0 to l.4.
For the purpose of the beforehand CAL learning effect, we have examined the weight rate of the learning for the student's score. The result obtained is given in Figure 7. A vertical line in the histogram is the weight rate of CAL learning, which is defined as the value that is obtained when the score for CAL learning is divided by the final score. Thus, if a student gets 9 points per l0 full mark from beforehand learning and has 7 points as his/her final mark, the weight rate is l.3. The value of the histogram means the % number of students. The left and right sides of the histogram have the same meanings as those shown in Figure 6. It was found that the beforehand learning effect is weak for lazy students. Compared with group A, a student in group B would get good marks, and the weight rate focusses on a histogram of l.0 to l.2.
Figure 7. Histogram of the weight rate of beforehand learning on students' scores.
A : students obtained less marks than the mean score, B : students achieved better marks than the mean score.