Final answer:
Instruct the mother to have her son rinse his face and eyes with water for at least 15 minutes.
Step-by-step explanation:
When a chemistry experiment blows up in someone's face, it is important to take immediate action before seeking medical care. In this case, the mother should instruct her son to rinses his face and eyes with water for at least 15 minutes. This will help to flush out any chemicals that may have come into contact with his face and eyes.