Putrescine [NH2(CH2)4NH2], found in rotting animal tissue, is now known to be in all cells and essential for normal and abnormal (cancerous) growth. It also plays a key role in the formation of GABA, a neurotransmitter. A 0.1 M aqueous solution of putrescine has [OH-] = 2.1 multiplied by 10-3. What is the Kb? Kb =