Piperidine (C_5H_11N) is an amine found in black pepper, K_b = 1.3 Times 10^-3.
ID: 959623 • Letter: P
Question
Piperidine (C_5H_11N) is an amine found in black pepper, K_b = 1.3 Times 10^-3. Calculate the K_a for the conjugate acid, C_5H_11N^+. Consider the weak acid, butanoic acid, C_3H_7COOH. Write the reaction for the proton-transfer reaction for this acid. Identify the acid, base, conjugate acid, and conjugate base in the above reaction. Look up the K_a for butanoic acid. What is the K_a for butanoic acid? Calculate the pK_a and the pK_b. How many moles of sodium hypobromite (NaBrO) should be added to 1.00 L of 0.050 M hypobromous acid (HBrO),o form a buffer solution of pH = 9.15? Assume that no volume changes occur when the NaBrO is added.Explanation / Answer
1. To find the Ka just use the Kw:
Ka = 1x10-14 / 1.3x10-3
Ka = 7.69x10-12
2. a) C3H7COOH + H2O <--------> C3H7COO- + H3O+
b) The acid is C3H7COOH, the base is the water, the conjugate base is the C3H7COO- and the conjugate acid is the H3O+
c) The Ka is 1.52x10-5, then:
pKa = -log(1.52x10-5) = 4.82
pKb = -log(1x10-14/1.52x10-5) = 9.18
Question 3 post it in another question thread.
Hope this helps