J.R. S. answered 07/19/20
Ph.D. University Professor with 10+ years Tutoring Experience
First, look at the balanced equation:
HCl + NaOH ==> NaCl + H2O
Next, we find the moles of NaOH being neutralized by the HCl. Then that will be equal to the moles of HCl needed since the balanced eq. shows they react in a 1:1 mole ratio. Finally, we'll convert moles of HCl to mls of HCl.
moles NaOH present = 1.33 g x 1 mol NaOH/40 g = 0.03325 moles NaOH
moles HCl needed = 0.03325 moles NaOH x 1 mol HCl/mol NaOH = 0.03325 moles HCl needed
volume HCl needed: since the HCl is 0.812 moles/L we use this to find liters or mls needed to provide 0.03325 moles.
(x L)(0.812 mol/L) = 0.03325 moles
x = 0.0409 L
x = 40.9 mls (to 3 significant figures)