Dear Monika,
That is not quite enough information to work with. Is it a procedure for determining cupric sulfate pentahydrate, or is that just one of the reagents? Omission of a step may simply mean that it is not required, that is, the solubility may be good enough for the procedure. Without know what the actual procedure is that you are referring to, I cannot really answer your question. A link to the document, or the complete text of that particular step would be helpful.
Best regards,
Steven
