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30 Cards in this Set
- Front
- Back
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What is the Bronsted Lowry Definition of an Acid? What is the Bronsted Lowry Definition of a Base?
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bronsted acid=proton donor,
bronsted base=proton acceptor |
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What is the Arrenhius defintion of an acid and a base?
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Arrenhius acid=donates H+ ions
Arrenhius base=donates OH- ions |
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What is the Lewis Acid defintion?What is the Lewis Base definition?
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Lewis acid=electron pair acceptor
Lewis base=electron pair donor |
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How are strong acids and strong bases classified? Weak Acids and Weak Bases?
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strong base= completely protonated
strong acid= completely deprotonated weak acid=partly deprotonated weak base=partly protonated |
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What is a conjugate acid?What is a conjugate base?
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conjugate acid=It is the species left when a base accepts a H+
conjugate base= it is the species left when an acid donates an H+ |
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What compounds are acidic oxides? What compounds are basic oxides?
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Acidic Oxides=Molecular compounds
Basic Oxides= Ionic compounds |
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What is an amphoteric substance?
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It is a substance that reacts both with bases and acids. Examples: Aluminum, beryllium, gallium, germanium, astatine, indium, tin, lead, antimony, and bismuth oxides
certain elements of the d block form amphoteric oxides, sc +3, ti+4, v+4, cr+4, mn+4, fe +3, +4, co+3, ni+3, cu 2+, zn 2+ |
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What is an amphiprotic substance?
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It is a substance that function as both an acid or a base, accepts a proton or donates it.
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What is autoprotolysis?
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When one molecule transfers a proton to antoher molecule of the same kind
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What is the autoprotolysis constant of water?
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Kw=1x10^-14
*Product of Hydronium ions and hydroxide ions will always remain constant to maintain value of Kw. |
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How do you find the pH of a solution? What is the pH of of pure water, an acidic solution, and a basic solution
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pH=-log[hydronium ion]
pH of pure water=7 base>7 acid<7 |
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How do we find the molarity of hydronium ions from pH
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[hydronium ion]=10^-pH
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How do we find the pOH of a solution?
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pOH=-log[OH-]
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How are the pH and pOH of a solution related?
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pH+pOH=pKw(14.00)
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What do we visualize in the molecular composition of a weak acid in water?
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Solution that contains:
1. Acid molecules or ions 2. Small concentrations of hydronium ions and the conjugate base of the acid formed by proton transfer to water molecules 3. Very, very small concentrations of OH- ions |
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What do we visualize in the molecular composition of a weak base in water?
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1. Base molecules or ions
2. Small concentrations of OH- ions and the conjugate acid of the base formed by proton transfer from water molecules 3. Very, very small concentrations of hydronium ions |
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What is the acidity constant? What is the basicity constant?
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Ka, represented by
Ka=[Hydronium ion][A-] ------------------- [HA] Kb= [HB+][OH-] ------------ [B] both these constants measure the acid and base strength, respectively |
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How is pKa or pKb measured?
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pKa=-log Ka
pKb=-log Kb |
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How is pKa and pKb related to the strength of the acid and base, respectively?
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The larger the value of pKa or pKa (the smaller the Ka and Kb), the weaker the acid and the base, respectively. & vice versa.
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What is the conjugate seesaw?
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The stronger the acid, the weaker its conjugate base
The stronger the base, the weaker its conjugate acid & vice versa |
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How are pKa and pKb related?
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pKa+pKb= pKw
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How is molecular struture and acid strength related?
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Acid Type Trend
--------------------------- Binary 1. More polar H-A bond, the stronger the acid. (observed for acids of the same period) 2. The weaker the H-A bond, the stronger the acid (observed for acids in the same grop) Oxoacid 1. The greater number of O atoms attached to the central atom (greater oxidation state), the stronger the acid. 2. For same number of O attached to thes ame central atom, the greater electronegativity of the central atom, the stronger the acid. Carboxylic: The greater the electronegativites of the groups attached to the carboxyl group, the stronger the acid. |
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How do you calculate the % deprotonation of an acid?
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% deprotonated=
molarity of A- ----------------------- x 100 initial molarity of HA Note that [hydronium]=[A-] |
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How do calculate the % protonation of a base?
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=molarity HB+
-------------- x 100 initial molarity B |
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What are the general trends in pH of salt solutions?
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An ion may be an acid or a base:
All cations that are conjugate acids of weak bases produce acidic solutions. Small highly charged metal cations can act as Lewis Acids in water such are Al 3+, and Fe 3+. Cations of group 1 and 2 metals, as well as those of +1 from other groups, are such weak Lewis acides that the hydrated ions do not act as acids. Very few anions that contain hydrogen produce acidic solutions (Dihydrogen phophate and hydrogen sulfate are exceptions) All anions that are conjugate bases of weak acids produce basic solutions Anions of strong acids, Cl-, Br-, NO3-, and Cl04- are such weak bases that they have no significant effect on the pH of a solution. |
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What is a polyprotic acid, base?
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A polyprotic acid is a compound that can donate more than one proton.
A polyprotic base is a compound that accept more than one proton. |
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What is the trend in the Ka's of a polyprotic acid?
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Ka1>Ka2>Ka3, meaning that the pKa increases for each, meaning that the strength of the acid decreases with each subsequent protonation.
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How do we estimate the pH of a polyprotic acid?
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By using the only first deprotonation equilibrium Ka1.
*Assume that further deprotonations are weak and that deprotonation is insignificant. |
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How do we describe the conjugate base of a polyprotic acid?
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Amphiprotic
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How do we estimate the pH of an aqueous solution of an amphiprotic salt?
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pH=1/2(pKa1+pka2)
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