What is the molar concentration of the naoh solution

0.397g/204=0.00194608mol this is the moles of the potassium hydrogen phthalate. Assuming the reaction ratio is 1:1 this is the same number of moles for the sodium hydroxide. we now use the solution triangle rearranged to find concentration. Moles/volume=concentration 
0.00194608mol/16.22ml/1000(to convert to decimeters cubed) 
Final answer is 0.00000012M-1.2x10-7

Yes i think so not 100 percent sure though

All the elements are arranged by melting points on the periodic table. in row they go from metals to gasses. in the row from sodium to argon, sodium is more reactive than the one on its right, magnesium.