calcululate the molality of CsCl in a 8% by mass aqueous solution. answer in units of m

Answer 1

8% WHAT? w/v perhaps.
8% w/v means 8g CsCl in 100 mL soln.
8g/molar mass CsCl = moles.
Then m = moles/kg solvent. But you don't have the density listed so you don't know the mass of the solvent.