Are larger airplanes more likely to stall? Stalls happen when the boundary layer on top of a wing slows so much that it essentially becomes part of the airfoil.



My question is, as the wings on larger aircraft present a longer flow path for the boundary layer, they slow the layer more. Right? So, would they not be more have a lower stall angle? Isn't this what is hinted at by the use of slots on airliner flaps?
Even assuming the same airspeed, a larger chord would increase the free-stream Reynolds number. As a general trend, higher free-stream Reynolds number will delay the stall boundary due to earlier transition to a turbulent boundary layer, as can be seen below for a 2D section data from wind tunnel:



Image ref: NASA Contractor Report 4745

This answer has a different and equally good illustration of the effect in terms of lift curves.

Of course, things get more nuanced in 3D, whether the airfoil is optimized for natural laminar flow, and in transonic flow, where the maximum lift trend with Reynolds number can reverse at an intermediate Reynolds number.