V ( NaOH) = 2.0 mL / 1000 => 0.002 L
M( NaOH) = ?
V ( HCl) = 4.0 mL / 1000 => 0.004 L
M(HCl) = 3.0 M
number of moles HCl:
n = M x V
n = 3.0 x 0.004
n = 0.012 moles of HCl
Mole ratio:
HCl + NaOH = NaCl + H2O
1 mole HCl ----------- 1 mole NaOH
0.012 moles HCl ----- ?
moles NaOH = 0.012 x 1 / 1 => 0.012 moles
M = n / V
M = 0.012 / 0.002
= 6.0 M
hope this helps!
