Question

The early alchemists used to do an experiment in which water was boiled for several days in a sealed glass container. Eventually, some solid residue would begin to appear in the bottom the flask. This result was interpreted to mean that some of the water in the flask had been converted into earth. When Lavoisier repeated this experiment, he found that the water weighed the same before and after heating, and the weight of the flask plus the solid residue equaled the original weight of the flask. Were the alchemists correct? Explain what really happened. (This experiment is described in the article by A. F. Scott in Scientific American, January 1984.)

Short answer

The residue of solid must come from flask. The solid which is newly formed comes from glassware of experiments.

Step-by-step solution

Conversion of mass in a reaction

The initial point is the get clear points on conservation of mass in a reaction. The compound mass in flask must be constant when there is nothing will escapes from flask.

Repetition of experiments by Lavoisier

The water’s mass is constant said by Lavoisier. It concludes that the residue of solid should come from flask. Both may be wrong. The solid which is newly formed comes from glassware of experiments.

Conclusion

The residue of solid must come from flask. The solid which is newly formed comes from glassware of experiments.