Chemistry Problem - Can you please help me!!!?

Question

http://i2.photobucket.com/albums/y48/xxkrystinaxx9/che.jpg


Solve for A and B
then C and D

Please help! i cant figure this out

Answer 1

The rate of reaction can be figured by calculating the change in concentration per unit of time. So, how does the concentration of N2O5 change over the first 300 seconds? The simplest way to calculate would be to take the total change in amount and divide it by the total time (= 300 seconds) to get a concentration/sec change. Then do the same thing for the last 300 second period. Are the rates the same? Note that the concentration is measured by molarity (M); the solution starts out at 1M and decreases in concentration over time.
As to the graph - what does the steepness of the slope of the line tell you about the rate of the reaction? For the last question, is there a relationship between the reaction rate and the concentration of the solution? How does the reaction rate change (if it does) as the concentration decreases?