Consider α , be very small ,by applying formula directly.
α=√KaC=√(6.4X10−5)0.1=2.53X10−2
In the presence ofNaOH , equilibrium will be shift in the backward i.e, the concentration of base will increase.
If C is the initial concentration,
X is the amount dissociated, then equilibrium will be:
[(C2H5)3N] = c−x,
[(C2H5)3NH+ =X,
[OH−] =0.01+X
∴Ka=X(0.01+X)c−x=X(0.01)X
Ka0.01=xc
but XC means α
α=Ka0.01=6.4X10−50.01=6.4X10−3
Hence, 6.4X10−3 is the answer.