In: Chemistry
3)Suppose a solution is prepared by dissolving 15.0 g NaOH in 0.150 L of 0.250 M nitric acid. What is the final concentration of OH- ions in the solution after the reaction has gone to completion. Assume that there is no volume change when adding the grams of NaOH.
mass of NaOH = 15 g
molar mass of NaOH = 40 g/mol
moles of NaOH = 15 / 40
= 0.375
moles of HNO3 = molarity x volume
= 0.250 x 0.150
= 0.0375
so
0.0375 moles of HNO3 react with 0.0375 moles of NaOH
remaining moles of NaOH = 0.375 - 0.0375 = 0.3375
final conentration of OH- = 0.3375 / volume
= 0.3375 / 0.150
= 2.25 M