properties of acid-base solution
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A solution of acidA solution of acid--basebasepropertiesproperties
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y Solution:A homogeneous mixture betweenthe solute and solvent
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Electrolyte
Strong
Electrolyte WeakElectrolyte
NaCl Na+ + Cl -
SOLUTION
Non Electrolyte
HCl H+ + Cl -
NaOH Na+ + OH -
CH3COOH mCH3COO- + H+
NH3(aq)mNH4++ OH-
C6H12O6 C6H12O6
C2H5OH C2H5OH
H2OmH++ OH-
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Strong
Electrolyte
strongacid
strongbase
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Strong acid is an acid which, when put ina lot of water releasing H+ ions.
Strong base is a base which, when put ina lot of water releasing OH-ions
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Strong Acids and BasesStrong Acids and Basesy Strong acids arethose that ionized
completely in water.y The dissociation of a
strong base look s lik ethe diagram at theright in that it dissociates into positive and negative
ions.
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T he number of ions H+ or OH-ions
can be calculated by using thefollowing formula
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Strong Acid
= 1
[H+]
[H+] = a . M
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y [ H+] = hydrogen ion concentrationCharacteristics of acid :- Acid can change blue litmus to red
[H+] = a. M
a : the amount of H in the formula acidM : Molarity
Example:H2SO4, HNO3, HI, HCl, HBr, HClO4
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Calculate [HCalculate [H++ ] of Strong Acids] of Strong Acids
0.250M H2SO4 is added to water to make afinal volume of 1 liter. What is the H+ of thissolution?
Answer :[H+ ] = a . M = 2 . 0,25 = 0,5
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Strong base
= 1
[OH-]
[OH-] = b . M
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[OH-] = concentration of hydroxide ionsCharacteristics of base :Base can change red litmus to blue
[OH-] = b. M
b : the amount of OH in the formula baseM : MolarityExample:
bases are formed by group IA and IIAFor example: NaOH, Ba(OH)2
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Strong BasesStrong Bases
*LiOH - lithium hydroxide*NaOH - sodium hydroxide
*KOH - potassium hydroxide*RbOH - rubidium hydroxide*CsOH - cesium hydroxide*Ca(OH)2 - calcium hydroxide
*Sr(OH)2 - strontium hydroxide*Ba(OH)2 - barium hydroxide
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Calculate pH of strong basesCalculate pH of strong bases
Determine OH- of a 0.750 M KOHsolution.
Answer :
[OH- ] = b . M = 1 . 0,75
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ExerciseExercise1. Determine the concentration of H+ ions
a. 100 ml of 0.01 M HNO3 solutionb. 9.8 grams of H2SO4 (Mr. 98) in wateruntil the solution volume 200 ml
2. Determine the concentration of OH-iona. 0.1 M NaOH solutionb. Solution of Ba(OH)2 0.05 Mc. Solution made from 2.8 grams of KOH(Mr=56) in water until the solution volume
100 ml
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3. Determine the [H+] a solution of thefollowinga. 50 ml of 0.05 M solution of HBrb. 2 liters of 0.02 M H2SO4 solutionc. Solution made from 3.65 g of HCl
(Mr 36.5) in the water until itsvolume of 2 liters.
d. Mixture of 100 ml of 0.04 M HCland 400 ml of 0.03 M HCle. 100 ml solution of 0.01 mol HI
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y Determine the [OH-] some of thefollowing solutionsa. 150 ml of 0.04 M KOH solutionb. 10-4M NaOH solution
c. 23 ml solution of Ba(OH)2 0.001 Md. Solution made from 8 gr NaOH is
dissolved in in water until thesolution volume 8 liters
e.Mixture of 2 liters of 0.6 M KOH and3 liters of Ba(OH)2 0.2 M
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WeakElectrolyte
Weak
acid
Weak
base
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Weak Acids and Bases
Weak Acids and Bases
y Some acids and bases
ionize only slightly in water.
y These are considered
weak.
y The most important
weak base is
ammonia.
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Weak acid is an acid which,when put in a water produces little of H+ ions
Weak base is a base which,when put in a water produces little OH-ions
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T o calculate the amount of
H+ or OH-ions by using thefollowing formula
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Weak AcidsWeak Acids
y HA(aq) m H+(aq) + A-(aq)
y [H+] = [ A- ]
[HA]
]A][[H ka
-
!
[HA]
][H ka
2
!
[HA].ka][H !
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Weak Acid
0<< 1
[H+]
[H+] = .M
[H+] = ¥Ka .M
= [H+]M
= ¥KaM
Ka> the more
powerf ul
properties
of acid
Example :
CH3COOH
H2CO3
H3
PO4
HCN
HCOOH
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ExampleExample
y Determine [H+] of 0.30 M aceticacid (HC2H3O2) with the Ka of1.8x10-5.
Answer :
[H+] = 2.3x10-3
[HA].ka][H !
[0,3].1,8x10][H 5
!
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Weak BasesWeak Bases
y LOH(aq) m L+(aq) + OH-(aq)
y [L+] = [ OH- ]
[LOH]
]OH][[L kb
-
!
[LOH]
][OH kb
2-
!
[LOH].kb][OH !
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Weak Base
0<< 1
[OH-]
[OH-] = .M
[OH-] = ¥Kb M
= [OH
-
]M
= ¥KbM
Kb > the more
powerf ul
properties
of base
Example :NH3
AL(OH)3Base areformed
other ofgroup IAand IIA
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ExampleExample
Determine the OH- of 0.15 Mammonia (NH3) with a Kb=1.8x10-5.
Answer:
[OH-] = 1.6x10-3 M
[LOH].kb][OH !
[0,15].x101,8][OH -5!
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ExerciseExercise
1. 600 ml of 0.01 M NH4OH solution has kb= 1.8 x10-5 determine [OH-] and
2. 2,24 liters of NH3
gas dissolved in waterso that the volume of 1 liter if kb = 1.8 x10-5 determine the concentration of OH-
3. 100 ml of 0.1 M solution of LOH has the
same concentration of OH-with 50 ml of0.001 M NaOH solution, determine kb
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4. 100 ml of 0.1 M CH3COOHsolution that has ka = 1.8 x 10-5
Determine the [H+] and 5. At a given temperature a 0.1 M
solution of HA decomposes 20%.Determine the [H+] and ka
6. 2.3 g of HCOOH (Mr. 56) wasdissolved in 250 ml of water until
its volume, if ka 1.8 x 10-4.Determine the [H+] and
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y Determine the [H+] of H3
PO4solution, 0,1 M if known :
Ka1 = 7.1 x 10-3
ka2 = 6.3 x 10-8
ka3 = 4.3 x 10-13
y Answer :[H+]1 = ¥ (7.1 x10-3) (0.1) = 2.7 x 10-2
[H+] = [H+]1 + [H+]2 + [H+]3
because [H+]2 and [H+]3 is very smallSo [H+] = [H+]1 = 2.7 x 10-2
1,0.10.1,7]H[3
!
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1. 0.01 M ,1500 ml HF have ka = 56.8 x10-4,determine the [H +] and
2. 15 g CH3COOH dissolved in water untilthe volume is 5 liters if Ka = 2x10-5
determine the [H+] and the percentage ofionized CH3COOH.
3. HA 0.2 M have ionized 25%, determinethe [H+] and Ka
4.Determine
[H
+
] of 0.1 M H2Aif knownKa1 = 10-7 and ka2 = 10-14
Exercise
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5, 100 ml of 0.1 M solution of NH2OH has kb = 10-8,
determine [OH-] and
6 600 ml of NH4OH solution is made by passing0672 liters of NH3 gas at ST P into the water if kb= 2.10-5 determine [OH-] and
7. A weak base LOH 0.1 M in water 2% ionizeddetermine [OH-] and kb
8. 2 liters of 0.003 M KOH solution with [OH-] is thesame with I liter of solution MOH 0,1 M determinethe ionization constant of weak base MOH.