1. The problem statement, all variables and given/known data Hello! I am trying to solve the following problem: A 4.00-L base solution contains 0.100 mol total of NaOH and Sr(OH)2 . The pOH of the solution is 1.51. Determine the amounts (in moles) of NaOH and Sr(OH)2 in the solution. 2. Relevant equations 3. The attempt at a solution I am stuck because I am not sure I correctly constructing the solution path: We have pOH = 1.51, which means that there are 10^(-1.51) moles of OH in solution, i.e. 0.0309 moles per one liter of solution. If I have 4 liters, then shouldn't there be 0.1236 moles of OH in this solution? But according to the problem there are only 0.100 moles of NaOH and Sr(OH)2; both are strong bases, therefore there 0.100 moles of OH in the 4 liters of solution. How can that be? Where is my mistake? Thank you very much!