how to make 750ml of 1.5 m solution of naoh

Answer 1

1. First you start sentences with a capital letter.
2. You end sentences with a period.
3. You learn to write formulas correctly; naoh and NaOH are not the same.
4. With that said, remember the definition.
molality = # moles/kg solvent.
Did you intend to write 1.5 m with 750 mL or you want the final volume to be 750 mL. I will assume you want to make 1.5 m solution of NaOH using 750 mL solvent. That's much easier to do. Also, I will assume the solvent is water.
Since m = #moles/kg solvent, then
1.5 m * 0.750 kg solvent = 1.125 moles.
1.125 moles x (1 mol NaOH/40 g NaOH) = 45.0 g NaOH. Then you add 0.75 kg water, dissolve, and mix thoroughly.