J.R. S. answered 09/28/20
Ph.D. University Professor with 10+ years Tutoring Experience
HCl + NaOH ==> NaCl + H2O ... balanced equation
The mol ratio of HCl to NaOH is 1:1
moles NaOH present = 50.00 ml x 1 L/1000 ml x 0.8000 mol/L = 0.04000 moles NaOH
moles HCl needed to neutralize this = 0.0400 moles HCl (1:1 mol ratio)
Volume HCl needed: (x L)(0.3750 mol/L) = 0.04000 moles
x = 0.1067 L