A school child is sensitive and good at studying chemistry. One day, to make phosphoric acid ($H_3PO_3 $), it is carefully prepared.

First take all the vessels, there are flasks, funnels, catheters, all clean and clean. Also prepare phosphorus elemental, hot water and other things, put on the case, orderly.

Then start the experiment, take a little phosphorus, put it in the container of hot water, to plug it, re-guide the tube, so that the gas is passed to other devices. Phosphorus meets hot water, gradually reacts, the heat evaporates, and bubbles escape. The school child stares, looking attentive, lest there is a mistake.

After a little while, the reaction is completed, and the resulting liquid is separated and purified many times. Or use filtration to remove its impurities; or apply distillation to analyze its pure liquid. Finally get phosphoric acid, put it in a bottle, observe its clear and transparent color, and the student's face shows a happy color.

This schoolchild studies the wonders of chemistry with diligence and sensitivity, and obtains phosphoric acid, which is another point in the way of chemistry.