Question

As + S => As2S3 правильно

Answer 1

2Al + 3S => Al2S3
Вот так
А такой как у вас реакции не существует

Answer 2

The chemical equation you provided seems to be incorrect. It appears to be a chemical reaction involving arsenic and sulfur, but the format is not accurate. The correct representation of the chemical reaction between arsenic and sulfur to form arsenic(III) sulfide (As2S3) is as follows:

2As + 3S → As2S3

This balanced equation shows that 2 moles of arsenic (As) react with 3 moles of sulfur (S) to produce 1 mole of arsenic(III) sulfide (As2S3).