(a) Define the following terms : (i) Molarity (ii) Molal elevation constant (K_(b)) (b)A solution containing 15 g urea (molar mass = 60 g mol^(-1)) per litre of solution in water has same osmotic pressure (isotonic) as a solution of glucose (molar mass = 180 g mol^(-1)) in water. Calculate the mass of glucose present in one litte of its solution.

(a) Define the following terms : (i) Molarity (ii) Molal elevation con

1.	(a) Define the following terms : (i) Molarity (ii) Molal elevation constant (K_(b)) (b)A solution containing 15 g urea (molar mass = 60 g mol^(-1)) per litre of solution in water has same osmotic pressure (isotonic) as a solution of glucose (molar mass = 180 g mol^(-1)) in water. Calculate the mass of glucose present in one litte of its solution.
Answer» Solution :(a) (i) Molarity is defined as NUMBER of moles of solute dissolved in one litre of solution. (ii) lt is equal to elevation in boiling point of 1 molal solution. (b) For ISOTONIC solutions : `pi_("urea") = pi_("glucose")` `(W_("urea"))/(M_("urea" xx V_(S)))= (W_("Glucose"))/(M_("Glucose" xx V_(s)))` (As volume of solution is same `(W_("urea"))/(M_("urea")) = ("glocose")/("glocose")` or `(15 g)/( 60 g" mol"^(-1)) = (w_("Glucose"))/(180 g "mol"^(-1))` `W_("glucose")= (15 g xx 180 g "mol"^(-1))/(60 g "mol"^(-1))`= 45 g