Mass transfer between a slender bubble and a Newtonian liquid in a simple extensional and creeping flow has been theoretically studied. The analytical steady-state solution when the Peclet number is zero has been obtained using the works of Szego and Payne, who studied the electrostatic capacity of a spindle surface in a bispherical coordinate system. The result shows, as expected, that the modified Sherwood number increases as the capillary number increases since the surface area of the bubble also increases.