chemistry from stoichiometry

Question

• 1kg of 1m glucose solution is diluted to 5kg the molality of the diluted solution should be 

Answer 1

It will be 1/5 of the original molality.  Recall that molality (m) is moles of solute/kg solvent.  1 m glucose represents 1 mole of glucose in 1 kg of solvent, so diluting it to 5 kg of solvent does not change the moles of glucose.  And since m is not based on final volume of solution, but rather just on kg of solvent, you now have 1 mole glucose in 5 kg solvent, which is 1/5 = 0.2 molal.