Solutions

Question 1

How to differentiate b/w solute and solvent

Answer 1

Solvent’s phase doesn’t change after mixing or, if same phase, one of greater quantity

Question 2

When is solvation endo/exothermic

Answer 2

If new attractions are stronger than solvent alone, exothermic. Otherwise endo

Question 3

Describe ideal solution

Answer 3

Enthalpy of dissolution = 0

Question 4

What are sparingly soluble salts?

Answer 4

Solutes that dissolve minimally in solvent

Question 5

What are the second 2 general solubility rules

Answer 5

3. All chlorides, bromides, iodides are water soluble, with exceptions of ones formed with Ag+, Pb2+, Hg.2 2+
4. All salts of SO4 2- are water soluble, except those with Ca2+, Sr2+, Ba2+, Pb2+

Question 6

What’s the one infallible solubility rule?

Answer 6

All sodium (Na+) salts and nitrate (NO3 2-) salts are completely soluble

Question 7

What do suffixes -ous/-ic, -ide, and -ite/-ate mean?

Answer 7

• ous: lesser charge than -ic
• ide: monoatomic anion
• ite: polyatomic oxyanion with lesser charge than -ate

Question 8

What do prefixes hypo and per mean?

Answer 8

When series of oxyanions contains 4,
1 = hypo...ite
2= ...ite
3 = ...ate
4 = per...ate

Question 9

What does bi and dihydrogen prefix mean?

Answer 9

Bi = single H addition (HCO3- = bicarbonate = hydrogen carbonate)
Dihydrogen = 2 H addition (H2PO4- = dihydrogen phosphate)

Question 10

Differentiate b/w electrolytes and nonelctrolytes

Answer 10

Electrolytes dissociate into ions in solution so can conduct electricity. Nonelectrolytes ionize weakly in solution

Question 11

Explain percent composition by mass

Answer 11

100% * Mass of solute / mass of sltn (solute + solvent)

Question 12

Explain mole fraction

Answer 12

moles of compound / # total moles of all species

Question 13

Explain molality

Answer 13

# mol solute / # kg solvent
Usually = molarity for dilute aqueous soltn's at 25ºC

Question 14

Explain normality

Answer 14

# mole equivalents solute / L solution
"Molarity of the stuff of interest"

Question 15

Calculate dilution

Answer 15

M1V1 = M2V2

Question 16

Calculate the Ksp of an ionic solid A.mB.n

Answer 16

K.sp = [A]^m * [B^n]

Question 17

What’s the ion product?

Answer 17

Equivalent to Q of the K.sp

Question 18

Describe the common ion effect

Answer 18

When an ion of a salt is already dissolved in a solvent, the solubility of that salt will be reduced. Results in same Ksp.

Question 19

What are the first 2 general solubility rules?

Answer 19

1. All salts of alkali metals are water soluble

2. All salts of NH4+ are water soluble

Question 20

What are the final 3 general solubility rules?

Answer 20

5. All metal oxides insoluble, except those with alkali metals and CaO, SrO, BaO which form turn into metal hydroxides in solution (CaO ==> Ca(OH)2)
6. All hydroxides are insoluble except those with alkali metals and Ca2+, Sr2+, Ba2+
7. All CO3 2-, PO4 3-, S 2-, and SO3 2- are insoluble, except those with alkali metals and ammonium