Osmotic pressure is the pressure that would have to be applied to a pure solvent to prevent it from passing into a given solution by osmosis.
That can be mathematical computed from the expression:
Osmotic pressure=C×R×T
Where,
C= Concentration
R=Gas constant
T=Temperature
Concentration=Number of moles of solute/Volume(L)
=0.005*1000/100
=0.05
R= 0.08206 atm L/mol K
T=25+273
=298
Osmotic pressure= 0.05×0.08206×298
=1.2 atm