A flask is charged with 0.140 mol of A and allowed to react to form B according to the following hypothetical gas-phase reaction.
A(g)--> B(g)

The following data are collected.

Times(s) Moles of A
0 0.140
40 0.064
80 0.050
120 0.033
160 0.019

(a) Calculate the number of moles of B at each time in the table.
0 s=____ mol
40 s=____ mol
80 s=____ mol
120 s=____ mol
160 s=____ mol

(b) Calculate the average rate of disappearance of A for each 40-s interval, in units of mol/s.
0 - 40 s= _____ mol/s
40 - 80 s=_____ mol/s
80 - 120 s=_____ mol/s
120 - 160 s=_____ mol/s

(c) What additional information would be needed to calculate the rate in units of concentration per time?
1. The mass of A must be known.
2. The molar concentration of A would be sufficient.
3. The volume of the container must be known.