Groundwater with a noncarbonated hardness (NCH) of 75 mg/L as CaCO3 is treated by a lime-soda process. The targeted hardness is 60 mg/L as CaCO Addressing only the NCH. How much Soda is required?
a. 135 mg/L as CaCO3
b. 55 mg/L as CaCO3
c. No Soda is required
d. 15 mg/L as CaCO3

Ahouse has the following electrical appliance usage (1) single 40w lamp used for 4 hours per day (2) single 60w fan used for 12 hours per day (3) single 200w refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours find the solar power inverter size in watt with correction factor of 1.25.

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

The drive force for diffusion is 7 fick's first law can be used to solve the non-steady state diffusion. a)-true b)-false