The correct answer is A. O^2-
Answer: CoBr3 < K2SO4 < NH4 Cl
Justification:
1) The depression of the freezing point of a solution is a colligative property, which means that it depends on the number of particles of solute dissolved.
2) The formula for the depression of freezing point is:
ΔTf = i * Kf * m
Where i is the van't Hoof factor which accounts for the dissociation of the solute.
Kf is the freezing molal constant and only depends on the solvent
m is the molality (molal concentration).
3) Since, you are assuming equal concentrations and complete dissociation of the given solutes, the solute with more ions in the molecular formula will result in the solution with higher depression of the freezing point (lower freezing point).
4) These are the dissociations of the given solutes:
a) NH4 Cl (s) --> NH4(+)(aq) + Cl(-) (aq) => 1 mol --> 2 moles
b) Co Br3 (s) --> Co(3+) (aq) + 3Br(-)(aq) => 1 mol --> 4 moles
c) K2SO4 (s) --> 2K(+) (aq) + SO4 (2-) (aq) => 1 mol --> 3 moles
5) So, the rank of solutions by their freezing points is:
CoBr3 < K2SO4 < NH4 Cl
We need to crack molecules in
order for us to get the desired molecule. For example, in the extraction of
crude oil, after entering the fractional distillation, it will give products
base on their molecular structure. The products are gasoline, diesel fuel, jet
fuel, wax, asbestos,kerosene.
There would be 67 left because you do
<u><em>Your Essay Must include:</em></u>
<u><em>Introduction:Brings the main idea,Must be atleast 3 sentences.</em></u>
<u><em>Body/Details:Supports the main Idea,Must be atleast 8 sentences.</em></u>
<u><em>Body/Details(Optional):Supports the main Idea,Must be atleast 8 sentences.</em></u>
<u><em>Conclusion:Tells a little more information.</em></u>
