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
Answer:
Start and end times; distance run.
Step-by-step explanation:
Average speed = distance/time.
Kaila should record the distance run, the time she started, and the time she ended her run.
The difference between the start and end times gives the time for the run.
If she inserts her numbers into the formula, she will get her average running speed.
Answer:
3
Explanation:
If oxygen reacts with iron, then both must be reactants and rust the product of that reaction
Answer:
The answer is B an open system allows energy and mass to move in and out of it
Hope it helps
Explanation:
The radial distribution function gives the probability density for an electron to be found anywhere on the surface of a sphere located a distance r from the proton. Since the area of a spherical surface is 4πr2, the radial distribution function is given by 4πr2R(r)∗R(r).
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