1.00 L of 0.15 N NaOH absorbed 11.2 millimole of CO2 from air. Hence, new molarity of NaOH is:

NaOH+CO2→Na2CO3+H2O1 L of 0.15 N0.15 mol              0.0112 molNaOH required by 0.0112 mol CO2 = 0.0224 molNaOH unreacted = 0.15 - 0.0224Thus, M (NaOH) = 0.1276 M