Chemical Equilibrium Flashcards
1
Q
Ksp
A
- dissosiation constant
- higher Ksp= more soluble compound
- experimentally found, obtained from a chart
- coefficients turn into exponents
- ICE tbl (MOLES) to find
- NO SOLIDS OR PURE LIQUIDS
concentration of reactant(s) - [A+]^a[B-]^b
2
Q
Common Ion Affect
A
- more of ions already in solution added lowers solubility of added reactant
- ions already present limits dissociation of more of same ions being added
- Ksp decreases, equilibrium shifted to reactants side of reaction
3
Q
Acid in water
A
- strong completely dissociates
- will form water with OH and shift equilibrium to products side
4
Q
Q < Ksp
A
- less than
- no ppt formed
5
Q
Q > Ksp
A
- greater than
- ppt formed
6
Q
Q
A
- reaction quotient
- relative amount products and reactants present
- changes as approach equilibrium
- [X]^x[Y]^y
7
Q
2 types of gravimetric analysis
A
- precipitation
- volatilization
8
Q
Precipitation
A
- solid generated from liquid phase medium
- precipitate “falls out” of supernatant (water above) via the use of excess of reagent
9
Q
Volatilization
A
- gas comes out of solid or liquid medium
10
Q
Precipitating agents
A
- specific
-selective
11
Q
Specific precipitating agent
A
- reacts w/ only one chemical species
12
Q
Selective precipitating agent
A
- reacts w/ limited # of chemical species
13
Q
4 qualifications to make good ppt
A
- easily filtered/washed (larger particles)
- low solubility
- unreactive w/ atmosphere
- known composition
14
Q
Colloidal suspension
A
- v small [(10^-7 - 10^-4) cm diameter] particles
- hard to filter/centrifuge
- fix via recrystallization
15
Q
Crystalline suspension
A
- larger particles
- settle spontaneously
- easy to centrifuge and filter
