1. Prepare a standard Iodine solution (e.g.0.05M) or prepare from a commercial available solution.
2. Dilute suitable volume of Hydrazine hydrate solution.
3. Pipete suitable volume of diluted Hydrazine solution to a conical flask and add ~2mL of starch solution as indicator.
4. Titrate with standard iodine solution until the solution turn blue.
Do you know how to calculate the concentration of hydrazine and then convert it to hydrazine hydrate?
This method is better than the method stated in Vogel's.