Question

The preparation of “azo” dyes often does not work well in the laboratory. Although the correct colour is usually apparent, very little product is obtained. Seeing this, a student decides to modify the experimental procedure and obtains a record quantity of product. Being very competitive, he does not want to let you in on his trick. However, you noticed that he added a liquid, and that he was monitoring the addition with pH paper. Knowing this, can you explain his high yield? Show equations.