1g/dm3 is equal to 0.001 g/ml. So, you need calculate: if 1ml solution contains 0.001 g salicylic acid, then you need take 50x0.001=0.05g salicylic acid and dissolve it in less than 50 ml solvent and add additional solvent up to 50 ml volume.
1g/dm3 is equal to 0.001 g/ml. So, you need calculate: if 1ml solution contains 0.001 g salicylic acid, then you need take 50x0.001=0.05g salicylic acid and dissolve it in less than 50 ml solvent and add additional solvent up to 50 ml volume.
I agree with Mr. Nodirali, m= mass concentration*V, as 1g/dm3 is equal 1g/L then m=1g/L*0.050L=0.050g. So you need dissolve 0.050g in 50 mL in a volumetric flask.