The kinetics of the chlorination of copper in the
thin film range at room temperature was studied by using
a wiped, rotating cylindrical copper cathode which was
partially submerged in an electrolyte. Experiments were
conducted at three different partial pressures: 1.00,
0.44 and 0.21 atm. of chlorine gas which was saturated
with water vapor.
The chlorination of copper was found to follow the
logarithmic equation
NAT= K
₁
In ( K
₂
t + 1.0 )
where W. is the weight of copper chloride formed per unit
area during exposure time t. The constant K1
was found
to be independent of the chlorine partial pressure while
the constant K₂
was proportional to the square root of
the chlorine partial pressure for the two pressure ranges
1.00 and 0.44 atm. The most satisfactory interpretation
of the experimental data is the mutually-blocking pores
mechanism in which the rate determining step is assumed
to be the transport of chlorine across the chloride film
through pores and paths of loosely arranged atoms