Calculate the approximate mass of naoh required to prepare 500 ml of a 0.15 m naoh solution

Formula for Molarity is given as,

                                      Molarity  =  moles / Volume of Solution in L     (1)
Also,
                                         Moles  =  mass / M.mass

Putting value of mole in eq. 1,

                                      Molarity  =  (mass / M.mass) / Vol
Solving for mass,
                                          Mass  =  Molarity × M.mass × Vol
Putting Values,
                                          Mass  =  0.15 mol/L × 40 g/mol × 0.5 L

                                          Mass  =  3 g
Result:
            Weight 3 g of NaOH, add it to a 500 ml volumetric flask, and add distilled water to the point of 500 ml. The resulting solution will be 0.15 M.

Ibelieve it's temperature! i'm not 100% sure.