1. The problem statement, all variables and given/known data Calculate the [H3O+] concentration (in M) in a 0.1 M aqueous solution of NH3. [Kb = 1.8 x 10–5 ] (a) 7.5 x 10–12 M (c) 1.8 x 10–6 M (b) 3.0 x 10–10 M (d) 1.3 x 10–3 M 2. Relevant equations ΔTb = Kb x m 3. The attempt at a solution So... I'm kind of at a loss here. First of all to do anything useful with the ΔTb = Kb x m equation, they would have to give ΔTb right? And also, because its an aqueous solution, I assume we are dissolving NH3 into water. The Kb of water is 0.512.... why then do they give a Kb value of 1.8 x 10–5? Thanks in advance The answer is a, btw, but why!?