Properties of Acid and Bases & Salts
~Theories~
Titration!
<- pH and Indicators ->
Acid/Base Calculations & Buffers
100
Acids react with bases and produce?
Salt and water
100
What is an Bronsted-Lowry Acid?
Proton Donor :)
100
what is the value of Kw?
1.00 x 10^-14 mol^2 dm^-6 at 298K
100
pH=x-pOH find x.
14 :)
100
what is the most practical method of making a buffer?
excess weak acid with strong base/excess weak base with strong acid
200
Carbonates and hydrogen carbonates will neutralize acids to produce?
Carbon dioxide and water
200
What is a Lewis Base?
Electron Pair Donor :D
200
Ka x Kb =?
kw
200
If the concentration of an acid is multiplied by 100 what is the difference in pH?
2
200
Define a buffer solution
an aquous solution of an acid and its conjugate base that resists changes in pH upon small additions of acid, base or water.
300
Ba(OH)2: Strong or weak base?
strong
300
Which of these is an acid base rxn according to the Lewis theory but not the Bronsted Lowry theory? A: NH3+HCL <--> NH4Cl B: 2H2O<-->H30++OH- C: NaOH+HCl<-->NaCl+H2O D: CrCl3+6NH3<-->[Cr(NH3)6]3++3Cl-
A... jk its D :P
300
what is the relationship between pKa and the strength of an acid?
lower the pKa the stronger the acid.
300
Define -> Indicator :)
Compounds that change color depending on whether they're in acidic or basic conditions
300
calculate the pH of a buffer solution containing 3.00 grams of sodium ethanoate in 100cm^3 of 0.050mol/L ethanoic acid at 298K (given that Ka for ethanoic acid = 1.8 x 10^-5 mol/L at 298K)
5.61
400
Metals above hydrogen in the reactivity series react with acids to produce?
Hydrogen gas and the metal salt
400
What is a ligand?
An ion or neutral molecule with one non bonding pair (Lewis base)
400
What are the 2 main chemicals responsible for acid rain?
NOx (oxides of hydrogen) and SO2
400
If Phenolphthalein is added to a solution and the solution turns pink/red what is a possible pH for the solution?
pH>7
400
Why are buffer soutions important in biological systems?
Because enzymes function efficiently only in narrow pH regions.
500
phenylamine (C5H5NH2) is not very polar and thus does not dissolve n water. However in the presence of HCl phenylamine readily dissolves in aqueous solution. Suggest a reason why.
HCl being a strong acid, reacts with the basic NH2 group of phenylamine which produces an ionic salt which dissolves in water.
500
What is the conjugate base of the conjugate base of the conjugate base of the hydronium ion?
Oxide ion, O2-
500
The pH of a 2M solution of hydrochloric acid is not on the pH scale. suggest why.
Ostwald's Dilution Law. The problem lies in the assumption that strong acids always dissociate 100%. More concentrated solutions of strong acids are not in fact completely dissociated, and solutions of all weak electrolytes become moree dissociated (stronger) in aqueous solution as the solution becomes more dilute.
500
How do you choose an appropriate indicator based on a titration curve?
The pH range of the indicator falls around it's pKa value, and so to be useful, the pKa must fall within the inflection of the titration curve.
500
explain how a system containing dissolved carbon dioxide (CO2(aq)), hydrogencarbonate ions (HCO3-(aq)) and carbonic acid (H2CO3(aq)) can act as a buffer when small amounts of acid or alkali are added.
Ms Reigh will tell you if the answer is correct...
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