Chapter 7, Problem 14P

A 20,000 L tank of water with pH of 7.5 is to be treated with a liquid hydrogen bromide acid (HBr). If after 5000 L of the acid was added to the volume in the tank the pH becomes 5.5, how much mass of hydrogen was added to the system? How much total HBr was added?

Determine the mass density, specific weight, and specific volume of CO2 contained in a vessel at a pressure of 800 kN/m2 and temperature 25°C.

The concentration of chlorine in a water tower tank was 2 mg/L when the tower was taken out of service. If the chlorine decays by first-order kinetics with a rate constant of 1.0 1/d, what is the chlorine concentration when the tank is put back in service 8 hours later? What mass of chlorine in kg must be added to the tank to raise the chlorine level back to 2 mg/L. (Assume completely-mixed tank).

Water with a dissolved oxygen (DO) concentration of 0.94 mg/L enters a well-mixed tankat a rate of 1500 L/min. The tank volume is 280 m3. In the tank, bacteria consume the oxygen for metabolism proportionally to the amount of oxygen present (if they use it at a rate r = k1 · DO, where k1 = 0.0021 min−1). Oxygen is dissolving into the water at a rate proportional to the degree of undersaturation (i.e., at a rate given by r = k2(DOsat − DO), where k2 = 0.0021 min−1 and DOsat = 8.5 mg/L. What is the steady-state concentration ofDO? Answer in units of mg/L.

Chloroform, CHCl3 a volatile liquid, was once used as an anesthetic but has been replaced by safer compounds. Chloroform boils at 61.7°C and has a heat of vaporization of 31.4 kJ/mol. What is its vapor pressure at 37.2°C?

An atomizer forms water droplets 45μm in diameter. Determine the excess pressure within these droplets using σ=0.0712N/m

In an insecticide-manufacturing unit, the gases coming out of a micro-fine grinding unit, containing 600 µg of sulfur / m3 of gas, are sent to a bag filter. If the flow rate of the gases through the bag filter is 1000 m3 / minute, how much sulfur will be separated in the bag filter in kg/day? Assume that all sulfur particles are separated in the bag filter.

Determine the mass of carbon tetrachloride that should be mixed with 80 kg of glycerin so that the combined mixture has a density of 1450 kg/m3.

Design of a community biogas plant for a village  consisting of 114 families, each family consisting of 5 persons (adults). Two children are equivalent to one person. Village survey report gives the following information’s about cattle’s Cows 185 (10 kg/day);       Oxes 135 (12 kg/day);     Buffalo 75 (15 kg/day)  ; pig 10 ( 3 kg/day); Gas produced from 1 kg of gobar in winter and summer 42 litre and 55 litre. Gas required for cooking/person/day = 0.227 m3 ,Gas required for lighting 100 cp lamp per hour = 0.126 m3 Each family is allotted 2 lamps, which would burn 3 hours daily, Density of slurry 1090 kg/m3 and retention time 35days.  Design the following parameters (i) gas required for cooking& Lighting (ii) Diameter of digester    Diameter d=