To determine the concentration of the sodium hydroxide (NaOH) solutions after being exposed to air at different time intervals, we need additional information about the initial concentration of the solutions and whether any reactions or changes occur during the exposure to air.
Without knowing the initial concentration and the specific conditions of the exposure to air, it is not possible to provide a precise answer. Additionally, the concentration of NaOH can change over time due to reactions with carbon dioxide (CO2) in the air, which can lead to the formation of sodium carbonate (Na2CO3) and water (H2O).
If you have the initial concentration of the NaOH solutions and information about the specific conditions of exposure to air, please provide that data, and I'll be happy to assist you in calculating the concentration at different time intervals.