What is the oh concentration of a solution in which 1.00 grams of sodium hydroxide?

1 gram of NaOH is equivilant to 0.025 moles of NaOH. 1 gram of NaOH / 39.997 g/mol = 0.025 moles. So if you want molarity you take the moles and divide by the liters of solution. Assuming 1 L since none was given the Molarity is 0.025 M