Usage: The software can be used without installation for printing labels of chemicals (both English and Chinese). The chemicals listed in the reference booklet "Classification and Labelling of Dangerous Substances Commonly Used in Industry" can be found in the software.
Sample of printout:
Download: The above software can be downloaded from the following website:
What advantage do we have if we use a computer to simulate an experiment ? This reminds me a conversation with Dr J Holbrook when we watched an animation of titration. If we can allow students to carry out the real experiment in a laboratory, why bother to carry out a titration simulation using computer. If the computer can do a real volumetric analysis, not a simulation, do we need to assess titration technique ? We did not come up to any conclusion. The following links are the simulations of two experiments in rate of reaction. Please justify the use of them in learning and teaching.
In an empty bottle containing white vinegar, which of the following substances, upon addition to the bottle, will result with the expansion of the balloon?
A. alum
B. baking powder
C. soda powder
The given answer is C.
What do you think?
Teaching tips
Ask your students to
1. search from the internet the chemical constituent(s) present in alum, soda powder and baking powder; and
2. write appropriate equations to illustrate their explanation.
The concepts involved in the movie clip will be suitable for most AL chemistry students, and will be a bit challenging to NSS chemistry students. If needed, teachers can provide more guidance for their students.
This experiment is to provide students with learning experience related to organic synthesis. In particular, students will learn a number of practical skills: heating under reflux, suction filtration and re-crystallisation. In addition, students have to handle quantitative problems: determining the percentage yield and the limiting reagent of a reaction. This experiment can be completed in two 40-minute lessons. The amounts of chemicals required are small.
Please see the draft documents, in English and Chinese, for details. Click here to download (updated on 6 Nov 09).
Acknowledgment :
Dr LL YEUNG and Dr Dennis CHAN, University of Science and Technology
Ms SC CHU and her team, Hong Kong True Light Middle School
Ms Anita LEUNG and her team, Ho Fung College (Sponsored by Sik Sik Yuen)
Mr WC LO and his team, S.K.H. Li Ping Secondary School
Volumetric analysis is the common method in determining the amount of hypochlorite or free chlorine in bleach. From the following website, you can find another suggestion for analysing the chlorine content of swimming pool water or bleach - using a colorimeter (Experiment 9.1). This is a good idea for students to carry out a scientific investigation on analysing chlorine content of swimming pool water or bleach using either instrumental method or quantitative method, or both.
