Step-by-step explanation:
Your results would be effected because there is a possibility that the water and chemical substance added into the flask will combine, possibly creating a reaction, either making the solution stronger or weaker, or possibly just messing up your experiment in one go.
For example:
If I paint a picture, and I have a cup that I use in order to put paint in, but the cup is wet and I put my paint in it, my paint will become more liquefied due to the fact water has been added to it, messing the paint up.