Shared Flashcard Set

Details

EChem Chapter 5
Defs, Concepts , Q&A
29
Chemistry
Undergraduate 4
11/14/2013

Additional Chemistry Flashcards

 


 

Cards

Term
How does freshly precipitated collodial iron(III) hydroxide interact with divalent metal ions in solution?
Definition
Freshly ppted colloidal iron(III) hydroxide effectively sorbs(complexes or chelates) divalent metal ions
Term
What is the meaning of "zero point charge" as applied to colloids? is the surface of a colloidal particle totally without charged groups at ZPC?
Definition
colloidal particles have equal numbers of + and - charges adsorbed to produce a net particle charge of zero. No there are still charged groups, the net sum of charges just equals zero.
Term
What is a general solubility chemical equation?
Definition
AB(s) A+ + B-
Term
What is intrinsic solubility?
Definition
Small amount of neutral salt goes into the aqueous solution.
Term
What is the general intrinsic solubility chemical reaction?
Definition
AB(s) <-> AB(aq)
Term
What is the general gas solubility chemical reaction?
Definition
X(g) <->X(aq)
Term
What does Henry's Law State?
Definition
At constant temperature the solubility of a gas in a liquid is proportional to the partial pressure of the gas in contact with the liquid
Term
Describe colloidal particles:
Definition
1 to 1x10^-3 um in diameter
Exhibit the Tyndall effect
Term
Define the Tyndall Effect:
Definition
The characteristic light scattering phenomenon of colloids that results from them being the same order of size as the wavelength of light.
Term
Define hydrophillic colloids
Definition
Single macromolecules with strong interactions with water (polar)
Term
Define hydrophobic colloids
Definition

Interact to a lesser extent w/ water

Ex. Inorganic crystals, clay particles, and petroleum droplets

Term
What are the three types of colloids?
Definition
1) Hydrophillic
2) Hydrophobic
3) Association
Term
Define zero point charge
Definition
At some intermediate pH, the sum of the surface charges equals zero
Term
Under what condition(s) do hydrophobic colloids aggregate?
Definition
1) Increase the ionic strength of the solution
2) Increase the secondary layer to reach zero point charge
Term
Define flocculation:
Definition
Uses bridging compounds to chemically bind particles
Term
Define Flocculating agents:
Definition
(Bridged compounds) polymers with high formula weight containing ionizable functional groups.
Term
Define association colloids
Definition
micelles
Term
Define micelles
Definition
aggregate clusters of mixed character molecules
Term
Define critical micell concentration:
Definition
occurs when the detergents aggregate to have hydrocarbon tails form a sphere w/ polar head outside to preclude the water on the inside.
Term
Define cation exchange capacity (CEC):
Definition
Measures the capacity of a solid to sorb (adsorb and/or absorb) cations
Term
Define adsorb
Definition
Reacts with surface charge(rapid)
Term
Define absorb
Definition
Reacts with interior components of matrix (slow has to diffuse through a solid)
Term
What does sorbtion vary with?
Definition
Varies with given pH and ionic strength
Term
Define exchangeable cation status
Definition

Amount of a specific ion bound to a given amount of sediment

Expressed as milliequivalents(of monvalent cations) per 100g of dry sediment

Term
What is the units for cation exchange capacity and exchangeable cation status
Definition
milliequivalents (of monvalent cation) per 100g of solid
Term
What is the partial pressure of water at 100% humidity?
Definition
0.0313atm
Term
What is the equation for Henry's law?
Definition

[X(aq)] = K PX

where [X(aq)] is aqueous conc of gass

K is Henry's constant for a particular gas

Pis partial pressure of the gas

Term
Write the Clausius-Clapeyron equation:
Definition
[image]
Term
What are the layers associated with hydrophobic colloid? Example PbS(Excess)+NaCl
Definition
Solid: PbSPbSPbS
Double electric layer: Pb2+ <-Matched up with S of solid layer, Excess Pb2+ is counter ion Secondary layer: Cl- and OH-<-Match up with Pb2+
Secondary layer and counter ions make up Double electric layer
Supporting users have an ad free experience!