Answer to Question #139259 in Inorganic Chemistry for asna

Question

calculate distance at which the interaction energy between two opposite elementary charges is equal to thermal energy (kbt) at 300k

1. vaccum
2.in water (e=80)

Answer 1

$$F = k{|q_1q_2| \over r^2}$$

At 300K ktb = 0.0259 eV

$$k = {1 \over 4\pi \epsilon}$$

$$r^2 = {k|q_1q_2| \over 0.0259} = {|q_1q_2| \over 0.0259*4\pi \epsilon}$$

a)

$$r^2 = {|1.6*10^{-19}*(-1.6*10^{-19})| \over 0.325304*0.0885*10^{-11}}$$