For question one, to calculate reaction rate, I believe you should use the following formula :
Reaction rate = change in quantity of something/change in time.
Knowing this, use the measurements for the first 2 points.
P1 = (1,16)
P2 = (2,30)
Then use the formula to solve for R.R.
30 - 16/2 - 1
14/1
14 cm^3/min.
I believe this is the solution.