how many calories do u burn in 2.5hrs power walking?

Answer 1

Not enough information provided as you current weight is needed. To find out, how many calories are burned go here:
http://www.fatburn.com/free_tool_activity_burn.asp

Choose your activity or the closest to it from drop down menu, enter your weight, click go. On the next page, choose the time spent and it will tell you how many calories you burned.