Jake R. answered  03/13/24
MCAT, SAT, Math, and Science Tutor with Rutgers teaching experience
To completely neutralize an acid, there must be one molar equivalent of base for every hydrogen atom produced. In this scenario, the first step is to find the number of moles of sulfuric acid. To do this, we divide the mass given by the molar mass of H2SO4 like so:
moles of H2SO4 = (g of H2SO4)/(MM H2SO4)
moles of H2SO4 = (25.0)/(98.08)
moles of H2SO4 = .255 moles
Then, to find the moles of hydrogen, we must multiply this by 2 since there are 2 moles of hydrogen in every sulfuric acid molecule. As such we are left with .510 moles of hydrogen. Since we know that the moles of hydrogen are equal to the moles of NaOH, we can then surmise that we need to add .510 moles of NaOH to neutralize this amount of sulfuric acid. Thus, our last step in this process is to multiply this number by the molar mass to get the final mass of NaOH needed to neutralize this sulfuric acid:
g of NaOH = (moles of NaOH)(MM of NaOH)
g of NaOH = (.510)/(40.0)
g of NaOH = 20.4
With that answer, we now know we need 20.4 grams of NaOH to neutralize 25.0 g of H2SO4.