A bubble of pure carbon monoxide (CO) gas at 1 atm, initially 0.2 cm in diameter, is held stationary in liquid water 25°C flowing at a constant velocity of 10 cm/s.

(a) Estimate the diffusion coefficient of CO in liquid water for these conditions.

(b) Estimate the convective mass transfer coefficient for CO at the gas-liquid interface assuming that the CO bubble can be treated as a solid sphere.

(c) Determine the initial rate of mass transfer of CO from the bubble to the liquid in mol/s.

(d) Write an equation to predict the rate of change of the diameter of the gas bubble.

(e) Calculate the initial rate of change of the bubble diameter in cm/s.

(f) Integrate your equation in

(d) to obtain an expression for the bubble diameter as a function of time. (g) Use your equation in

(f) to predict the time needed for the bubble diameter to become one half of the initial value. See Perry’s Table 12-21 for gas solubility data.