Hydrochloric acid (A) diffuses through a thin film of water (B) 4 mm thick at 283 K. The concentration of HCl at point 1 on one boundary of the film is 12 wt. % (density = 1060.7 kg/m) and on the other boundary, at point 2 is 4 wt. % (density = 1020.15 kg / m). The diffusivity of HCl in water is 2.5 x 10- m /s. Calculate the flux of HC1 when (1) water is stagnant; (ii) when both are under equimolal counterdiffusion.