Answer:
Step-by-step explanation:
formula of osmotic pressure is as follows 
p= n RT 
n is mole of solute per unit volume 
If m be the grams of solute needed 
m gram = m / 227.1 moles 
m / 227.1 moles dissolved in .279 litres 
n = m / (227.1 x .279 ) 
= m / 63.36 
substituting the values in the osmotic pressure formula 
5.14 = (m / 63.36) x .082 x 298 
m / 63.36 = .21 
 m = 13.32 grams .