Question

A.Calculate the molar concentration of OH? ions in a 6.7

Answer 1

Ethyl amine is a base and it reacts with water to produce hydroxide ions

                CH₃CH₂NH₂ + H₂O --> CH₃CH₂NH₃⁺ + OH^-

Initially         6.7 X 10^-2                    0                       0

At equilib      6.7 X 10^-2 - x                x                   x

So

Kb = [CH₃CH₂NH₃⁺][ OH^-] / [CH₃CH₂NH₂]

6.4 X 10^-4 = x² /6.7 X 10^-2