Suppose you wanted to dissolve 40.0 g naoh in enough h2o to make 6.00 l of solution

Questions are as follow, and answered one by one,

(1) What is step 1 in solving the problem? 

             First of all moles of NaOH are calculated. This is done by applying following formula,

                            Moles  =  n  =  Mass / M.mass

(2) What is the molar mass of NaOH? 

              Add all atomic masses of elements in NaOH to find the Molar mass.

                       Atomic Mass of Na  = 22.98 g/mol

                       Atomic Mass of O  = 16.00 g/mol

                       Atomic Mass of H  = 1.008 g/mol
                                                     

           Molar Mass of NaOH        =  39.988 g/mol

(3) What is the Molarity of this solution?


                             Molarity  =  Moles / Vol

 ∴ Moles  =  40g / 39.988g/mol  =  1.0 mol 
So,
                             Molarity  =  1.0 mol / 6.0 L

                             Molarity  =  0.16 mol.L⁻¹