Hydrochloric acid (HCI) diffuses through a thin film of water (2.0 mm thick) at 290 K The concentration of HCl at point l on one boundary of the film is 8% by mass and on the other end of the boundary, at point 2 is 5% by mass. Density of the solution mixture at points 1 and 2 are 1080 kg/m3 and 1060 kg/m3 respectively. The diffusivity of HCI in water is 2.6 x 10-8 m2/s. Calculate the molar flux of HCl assuming water to be stagnant. Assume that the net molar concentration remains almost constant across the film (or take an average of the concentrations on both sides of the film).

Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.

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

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false