Question

what is the excess reactant of H2SO4+2NaOH->Na2SO4+2H2O
H2SO4: NaOH:
n=? n=?
c=0.025M c=0.030M
v=0.4L v=0.4

Answer 1

This site doesn't handle spaces very well. I assume you mean 0.4 L of 0.025M H2SO4 with 0.4 L of 0.030M NaOH.

mols H2SO4 = M x L = approx 0.01
mols NaOH = M x L = approx 0.012

For 0.01 mols H2SO4 you need 0.02 mols NaOH and you don't have that much so NaOH must be the limiting regent. That makes H2SO4 the excess reagent.