The Solution Process Edward A. Mottel Department of Chemistry Rose-Hulman Institute of Technology.
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Transcript of The Solution Process Edward A. Mottel Department of Chemistry Rose-Hulman Institute of Technology.
04/18/23
Solutions
Reading assignment:• Zumdahl: Chapter 4.1-4.3, 17.2
Atomic level perspective Molecular versus Ionization Solution concentrations
Water
O
HH • •
• • • •
• • O
HH
water has a nonlinear structure(bent molecule)
water has a dipole (polar)
-
++
Polar bonds form when elements of differentelectronegativity bond together.
OH
H-
++
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Where would hydrogen belong in the periodic table,if the table was organized by period and electronegativity?
C C
CH2OH
HO
H
H
O
C
H
C
HO
HOHC
H
OC
CH2OHO
CH
CH2OHC
HO
H
C
HO
HOHH
OHH
OHH
OHH
OHH
OHH
sucrose(aq)
A hydrogen bonds forms when hydrogen bridgesbetween two very electronegative elements.
intermolecular bonds
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-
OHH
OHH
OHH
OHH
OHH
OHH
OHH
OHH
+
OHH
OH
H
OH
H
OHH
NaCl(s) + H2O(l) Na+(aq) + Cl-(aq)
rock salt
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Ionic BondsElectrostatic Attraction
Na+
Cl – • • •
•
• • • •
E = k · q1 · q2
d
Compounds with ionic bonds generally havehigh melting points.
OH
H-
++
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Some Salts are Soluble
Solubility depends on temperature and the solvent
Soluble salts• Group IA, NH4
+, NO3–, CH3COO–, ClO3
–, ClO4–
• Most halides (Cl–, Br–, I–)· except Ag+, Cu+, Hg2
2+, Pb2+, Tl+ • Most sulfates
· except CaSO4, SrSO4, BaSO4, Ag2SO4, HgSO4, PbSO4
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Things to Think About whenWriting a Chemical Equation.
What is the formula of the reactant & product?
What is the phase of the reactant & product? Does it dissolve?
• What would you observe?• How could you predict it?
Write an equation for what occurs whensolid sodium hydrogen carbonate
is mixed with water.
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Solid Sodium Hydrogen Carbonate is Mixed with Water
NaHCO3(s) NaHCO3 (aq)
NaHCO3 (s) Na+(aq) + HCO3–
(aq)
How could you tell?
Does it ionize?
NaHCO3 (s) Na+(aq) + H+(aq) + CO32–
(aq)
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Solid Sodium Hydrogen Carbonate is Mixed with Water
NaHCO3 (s) Na+(aq) + HCO3–
(aq)
Compounds which break into ions and conductelectricity are called electrolytes.
When a salt dissolves,it breaks into its named ions.
What ions form when the following salts dissolve?
calcium acetate
lead(II) nitrate
K2SO4
CuCl2
Write an equation for the dissolution of each ofthe above compounds in water.
When a salt dissolves,it breaks into its named ions.
Ca(CH3COO)2(s) Ca2+(aq) + 2 CH3COO–(aq)
Pb(NO3)2(s) Pb2+(aq) + 2 NO3–(aq)
K2SO4(s) 2 K+(aq) + SO42–(aq)
CuCl2(s) Cu2+( aq) + 2 Cl–(aq)
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Some Salts are Not Very Soluble
Sparingly soluble salts• Most hydroxides
· except Group IA, Ba(OH)2• Sulfides
· except Group IA, Group IIA, NH4+
• Carbonates, phosphates, sulfites
· except Group IA, NH4+
Reactions can occur when solutions containingdifferent ions are mixed.
An aqueous solution of calcium acetateis mixed with an aqueous solution of
potassium sulfate.
Ca2+(aq)
CH3COO–(aq)
K+(aq)
SO42–(aq)
double displacement reaction
Ca2+(aq) + 2 CH3COO– (aq) + 2 K+(aq) + SO4
2–(aq)
CaSO4(s) + 2 K+(aq) + 2 CH3COO– (aq)
Ca2+(aq) + SO42–(aq) CaSO4(s)
total ionic equation
net ionic equation
Write the net ionic equation for the reaction oflead(II) nitrate and copper(II) chloride.
Pb2+(aq) + 2 NO3–(aq) + Cu2+(aq) + 2 Cl–(aq)
PbCl2(s) + Cu2+(aq) + 2 NO3–(aq)
Pb2+(aq) + 2 Cl–(aq) PbCl2(s)