yes, I'm sure NaOH was 50%. So I divide the number of moles by 2 giving:
NaOH (50%) = 3424.6/2 moles = 1712.3 moles
Urea = 1193.07 moles
DDBSA (dodecylbenzenesulfonic acid) = 564722.5 grams = 1729.8 moles
(Water - 5127 lbs (18.02 g/mol M.W.) 5127 lbs = 2325568 grams = 129054.83 moles)
As Urea pH is 7.2 at 100g/L of water it should not contribute significantly to pH changes, unless something happens when mixed with the rest of the ingredients.
I assume DDBSA is a strong acid, NaOH is a strong base so if H+ and OH- will dissociate completely (amount of moles used was almost 1:1) we should get pH about 7. (the range defined 6.0 - 8.0 allows for some changes in the quantities taken). Am I right so far?
Anyway, I've got pH 13.1 and the weight of the solution was as expected assuming all ingredients were added in the correct amounts. So how it happened? Is there any way Urea contributed to the pH change? The order of adding ingredients is water, urea, 50%NaOH and DDBSA. If the order will be changed does it matter?