Answer
a) heat enters the system
b) greater in the area from $1.00-2.00 m^3$
c) $Q=277KJ$
d) $Q=115\times 10^3J$
Work Step by Step
(a) Since the gas expands, heat enters the system.
(b) We can see from the figure that area from $1m^3$ to $2m^3$ is greater than the area from $3m^3$ to $4m^3$ as the magnitude of the change in the pressure is more in the $1m^3$ to $2m^3$ region.
(c) We know that
$Q=nR(\frac{P_iV_i}{nR})\ln (\frac{V_f}{V_i})$
We plug in the known values to obtain:
$Q=(400KPa)(1m^3)\ln(\frac{2m^3}{1m^3})$
$Q=277KJ$
(d) As $Q=P_fV_f\ln(\frac{V_f}{V_i})$
We plug in the known values to obtain:
$Q=(100KPa)(4m^3)\ln(\frac{4m^3}{3m^3})$
$Q=115\times 10^3J$
