A soaked sponge is experiencing dry air flowing over its surface. The air is at 1 atm and zero relative humidity. Determine the difference in the air temperature and the surface temperature of the sponge, T_∞ - T_s, when steady state conditions are reached, if the sponge is soaked with

(a) water, D_AB = 2.42 × 10^-5 m²/s,

(b) ammonia, D_AB = 2.6 × 10^-5 m²/s. Evaluate the properties of air, water, and ammonia at 20°C, 10°C, and 240°C, respectively.