A solution is made by dissolving 21.5 grams of glucose (C6H12O6) in 255 grams of water. What is the freezing point depression of the solvent if the freezing point constant is -1.86 °C/m? Show all of the work needed to solve this problem.

Question

amariiiaaa · Answer

can someone please help me

sweetburger · Answer

$$\Delta T = iK_fm$$
In this equation Delta T represents the change in temperature from the freezing point, i represents van hofts factor which in this case is equivalent to 1 as glucose does not ionize in solution (so you can basically ignore it), K_f represents the freezing point constant, and m represents molality which is (moles of solute)/(kilograms of solvent). 
Basically all you need to do is find the molality of the solution.
Start with converting the grams of glucose to moles of glucose. Then divide the moles of glucose by the kilograms of water.
From there you are ready to plug and chug to find Delta T.