experiment 6 Flashcards
What are substances that only conduct electricity when dissolved?
Electrolytes
What do NON-ELECTROLYTES contain for them not being able to conduct electricty?
molecules
Main reason why electrolytes conduct electricity when dissolved
dissociation of molecules into ions
UNIQUE electrolytes process
conduction of electric current is facilitated by movement of charged species within a covalent compound
What do you call the unique electrolytes that possess this unique ability? (3 ways you can call it)
Covalent Electrolytes
Molecular Electrolytes
Non-metallic Electrolytes
2 main categories of electrolytes
+ difference between the two
Strong Electrolytes (complete dissociation in water=production of many ions)
Weak Electrolytes (partial dissociation in water=production of few ions)
Examples of Strong & Weak Electrolytes
STRONG: strong acids and bases
WEAK: weak acids and bases
Strong Acids Examples (8)
HCl
HBr
HI
HNO3
H2SO4
HClO3
HClO4
Sulfonic Acids
Strong Bases Examples (9)
Commonly Group 1 & 2 + OH
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
ammonium hydroxides
Difference in ARROWS used in
COMPLETE dissociation
PARTIAL dissociation
COMPLETE: one arrow
PARTIAL: two arrows
Ki vs Ka vs Kb
Ki: concentration of water in dilute solutions
Ka: ionization in acids
Kb: ionization in bases
_____ of ions determines conductivity
+ how can you measure this?
concentration
conductivity measurements
Conductivity DEFINITION
how well solutions allow the flow of electrical charges (ions)
Unit for CONDUCTIVITY
Siemens/meter
Siemens/centimeter
Tool used to measure conductivity
Pen-type conductivity meter
Molar conductivity DEFINITION
Conductivity of solution containing
ONE mole of electrolyte / Liter solution
Unite for Molar Conductivity
Siemens/meter
Siemens/centimeter
After serial dilution, WHAT FORMULA will you use to calculate the final concentration?
Dilution Formula
C1V1 = C2V2
What is fraction dissociation?
- measure of the degree to which a weak ACID/BASE dissociates in a solution
OR
- the fraction of the initial concentration of a weak acid/base that has undergone dissociation
Limiting Conductivity Definition
- conductivity of an electrolyte when completely dissociated at infinitely low concentrations
Limiting Conductivity represents the ____________ conductivity achievable by an electroly
maximum
Corrected Experimental Conductivity
Unit
Notation
Formula
uS / cm
Λc
Λc = Λof experimental sample - Λdistilled H2O
Molar Conductivity
Unit
Notation
Formula
uS / (cm * M)
Λm
Λm = (Λc of experimental sample) / (concentration of sample)
Fraction dissociation
Unit
Notation
Formula
No unit
∝
∝ = (Λm of exp sample) / (Λo of exp sample)
Λo is given
what is Λo
a constant value different per sample
Λo of acetic acid
3.955 x 10^5 uS / (cm * M)
% dissociation / % ionization
Unit
Formula
%
% ionization = ∝ * 100
Acetic ACID reaction equation
CH3COOH (aq) + H2O (l) -> <- H3O+ (aq) + CH3COO- (aq)
ICE Table for ACETIC ACID REACTION
+ how to get value of x
I: 0.50 0 0
C: -x +x +x
—————————————————-
E: 0.50 -x x x
x = %ionization * concentration of sample
kasi hinahanap natin amount value ng “NA-DISSOCIATE” na ions ng sample after the reaction took place
% error
formula
% error = [(Ki experimental - Ki theo) / Ki theo] * 100
What is the theoretical Ki of acetic acid
1.75 x 10^-5
As the concentration of an experimental sample increases, its fraction dissociation ___________________
decreases
