A gas stream contains 4.0%NH3 and its ammonia content is reduced to 0.5mol% in a packed absorption tower at 293K and 1 atm. The inlet pure water flow is 68.0kgmol /h and the total inlet gas flow is 57.8kgmol/h. The tower diameter is 0.747m. The film mass transfer coefficients are kya=0.0739kgmol/(m3.s.molfrac) and kxa=0.169kg mol/(m3.s.mol frac.). Using the design methods for dilute gas mixtures, calculate the tower height using ky 'a