Answer is: molarity of sodium hydroxide solution is 1.95 M.
m(NaOH) = 68.4 g.
n(NaOH) = m(NaOH) ÷ M(NaOH).
n(NaOH) = 68.4 g ÷ 40 g/mol.
n(NaOH) = 1.71 mol.
V(NaOH) = 875 mL ÷ 1000 mL/L = 0.875 L.
c(NaOH) = n(NaOH) ÷ V(NaOH).
c(NaOH) = 1.71 mol ÷ 0.875 L.
c(NaOH) = 1.954 mol/L.
