Solutions

Question 1

when new interactions in a solution are stronger than the original ones, solvation is ____ and the process is favored at ____ temps.

Answer 1

exothermix, low

ex; dissolution of gases into water

Question 2

when new interactions in a solution are weaker than the original ones, solvation is ____ and the process is favored at ____ temps.

Answer 2

endothermic, high

ex; most dissolutions

Question 3

ideal solution

Answer 3

enthalpy of dissolution is zero

Question 4

relationship between G, H, T, and S

Answer 4

ΔG = ΔH - TΔS

Question 5

7 solubility rules

Answer 5

1. All salts containing ammonium (NH4 +) and alkali metal (Group 1) cations are water-soluble.
2. All salts containing nitrate (NO3 -) and acetate (CH3COO-) anions are water-soluble.
3. Halides (CI-, Br- , I-), excluding fluorides, are water-soluble, with the exceptions of those formed with Ag+, Pb 2+, and Hg 2+.
4. All salts of the sulfate ion (SO4 2-) are water-soluble, with the exceptions of those formed with Ca 2+, Sr 2+, Ba 2+, and Pb 2+.
5. All metal oxides are insoluble, with the exception of those formed with the alkali metals, ammonium, and CaO, SrO, and BaO, all of which hydrolyze to form solutions of the corresponding metal hydroxides.
6. All hydroxides are insoluble, with the exception of those formed with the alkali metals, ammonium, and Ca 2+, Sr 2+, and Ba 2+.
7. All carbonates (CO3 2-), phosphates (PO4 3-), sulfides (S 2-), and sulfites
   (SO3 2-) are insoluble, with the exception of those formed with the alkali metals and ammonium.

Question 6

complex ion/coordination compound

Answer 6

• a cation is bonded to at least one electron pair donor (these are called ligands which could include the water molecule)
• held together w coordinate covalent bonds
• very stable Lewis acid-base adducts
• important in protein active sites including those of coenzymes

Question 7

chelation

Answer 7

• in a complex, central cation bonded to the same ligand in multiple places
• requires generally large organic ligands that can double back to form second or even third bond with central cation
• can be used to sequester toxic metals

Question 8

% comp by mass

Answer 8

mass of solute/mass of solution • 100%

Question 9

mole fraction

Answer 9

XA = moles of A/total moles of all species

Question 10

molarity

Answer 10

M = moles of solute/L of soln

Question 11

molality

Answer 11

m = moles of solute/kg of solvent

Question 12

normality (N)

Answer 12

• # of equivalents of interest/L of soln
• 1M permanganate ion readily accepts 5 moles of electrons

Question 13

dilution

Answer 13

MiVi = MfVf

Question 14

solubility product constant/ion product

Answer 14

Ksp/IP = [A^n+]^m • [B^m-]^n

• IP < Ksp: unsat, dissolve
• IP = Ksp: sat, eq
• IP > Ksp: super sat precipitation

Question 15

solubility constant inc for non gas solutes as…

Answer 15

temp inc. this dec gas solubility tho

Question 16

Ksp larger for gases at…

Answer 16

higher pressures

Question 17

The formation of complex ions _____ the solubility of a salt in soln.

Answer 17

inc

Question 18

Raoult’s Law

Answer 18

PA = XA • P°A

P new pressure
P° A vapor pressure

Question 19

BP elevation and FP depression

Answer 19

ΔTb = iKbm
ΔTf = iKfm

Question 20

osmotic pressure

Answer 20

Π = iMRT