I need help findnig out the error involved with using a graduated cylinder and gas collection tube to calculate the rate of reaction.

We beed more details than you have provided. What kind of experiment did you do? What reaction was involved? How did you use the graduated cylinder and gas collection tube? Other details?

oh its ok i figured it out :)

Great! I'm glad you figured it out. If you need any further assistance or have any other questions, feel free to ask.