A solution of glucose (C6H12O6) is isotonic with 4 g of urea (NH2−CO−NH2) per litre of solution. The concentration of glucose is:

Isotonic solution has same conc. π1=π2 ;C1=C2 ;n1V1=n2V2 ;                    Since,V1=V2=1 ; n1=n2                                 W1M1=W2M2                                 x180=460                                      x = 12gm