HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)
As you can see here, one mole of acid neutralizes one mole of base.
We use the concentration equation, which states that,
c=nv
n is the number of moles v is the volume of solutionRearranging for moles, we get,
n=c⋅v
So, we have:
nNaOH=0.1 M⋅0.05 L
=0.005 mol
Since one mole of acid neutralizes one mole of base, then we must have: nHCl=nNaOH.
And so,
cHCl=nHClvHCl
=0.005 mol0.03 L
≈0.17 M
