Draw a typical DO curve for a BOD run at the following conditions.
a. Stream water, 20°C, dark
b. Unseeded sugar water, 20°C, dark
c. Stream water, 20°, with light
d. Stream water, 40°C, dark

For a process taking place in a closed system containing gas, the volume and pressure relationship is pvi-constant. -1.5 bar, the process starts with initial conditions, pi = =0.03 m3 and ends with final volume, v2-0.05 m3 determine the work done by the gas.