What is relation between mole fraction and molality of solute ?

ILLUSTRATIVE EXAMPLES:

(1):Calculate the mole fraction of solute in the 12 molal aqueous solution of CaCO3.

(2):The mole fraction of glucose in aqueous solution is 0.2 , The molality of solution will be.

(3):If the mole fraction of a solute is changed from 1/4 to 1/2 in the 800 gm of solvent . then the ratio of molality will be .

(4):Mole fraction of I2 (iodine) in benzene (C6H6) is 0.2 . Calculate the molality of iodine (I2) in benzene.

(5):Calculate the amount of water that should be added to 16 gm methanol to make mole fraction of methanol as 0.25.?