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:
See the answer below , please.
Explanation:
In a decomposition reaction, a certain compound is "broken" to give two or more different products.
An example for compound AB, giving as products A and B:
AB -> A + B
In the case of water:
2H20 -> 2H2 + 02, water decomposes giving Hydrogen and Oxygen
20 mol of NH, can be produce from 30 mol o H2
It would be B.both solar thermal energy and solar electric energy.
Answer: 9.68 x 10^10 grams.
Explanation:
Given that:
Mass of CO2 = ?
Number of molecules of CO2 = 2.2x10^9 molecules
Molar mass of CO2 = ? (let unknown value be Z)
For the molar mass of CO2: Atomic mass of Carbon = 12; Oxygen = 16
= 12 + (16 x 2)
= 12 + 32 = 44g/mol
Apply the formula:
Number of molecules = (Mass of CO2 in grams/Molar mass)
2.2x10^9 molecules = Z/44g/mol
Z = 2.2x10^9 molecules x 44g/mol
Z = 9.68 x 10^10g
Thus, the mass of 2.2x10^9 molecules of CO2 is 9.68 x 10^10 grams.
