Question

Suppose you dissolve 0.1 moles of 1-aminobutane (NH2-CH2-CH2-CH2-CH3) in 1.0 liter of water. a. What are all of the molecules and ions you would expect to find in the solution? b. Which two of the above will be found in the greatest total amount? Hint: what is the approximate pKa of an amino group?) c. Which one of the above will be found in the least total amount?

Answer 1

a) The two compounds you will expect in these solution are 1-aminobutane and its conjugate acid.

b) The greatest total amount is of 1-aminobutane.

c) The least total amount is of the conjugate acid.

Step-by-step explanation:

The equilibrium in water of 1-aminobutane is:

CH₃(CH₂)₃NH₃⁺ ⇄ CH₃(CH₂)₃NH₂ + H⁺

a) The two compounds you will expect in these solution are 1-aminobutane and its conjugate acid.

b) The equlibrium constant is: K = 1,66x10⁻¹¹.

That means you will have 1-aminobutane:Conjugate acid in a ratio of 6x10¹⁰ : 1 .

The greatest total amount is of 1-aminobutane

c) Thus, The least total amount is of the conjugate acid.

I hope it helps!