Quiz4
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Chemistry 173
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1) A solution of 0.100 M is prepared of benzoic acid (C6H5COOH) Ka =6.3 x 10-5and another solution of 0.100 M of
chloroacetic acid (CHzCICOOH) Ka= 1.4 X 10'3. At equilibrium
a) which solution has the lowest pH?
b) which acid solution has the largest [OH-]
benzoic acid
benzoic aci
Froacetic
aci<IJ
chloroacetic acid
c) which conjugate base has the largest Kb?
C6H5COO'
CHzCICOO-
d) which solution has the smallest percent dissociation?
benzoic acid
chloroacetic acid
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2) What is the pH of a 0.050 M solution of formic acid (HCHOz)? Ka =1.8 x 10-4
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3) A 0.10 solution of adipic acid (Ka = 3.8 x 10'5)was found to be 1.9 % dissociated.
a) What is the pH of this solution?
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4) Determinethe pH of a 6.7 x 10'5M solutionof Sr(OHh.
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5) Calculate the pH of a 0.030 M solution of (C6H5NH3)CI.Kb(C6H5NHz)= 4.0 x 10-10
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6) Identify whether an aqueous solution of the following would be expected to be acidic (A), basic (B), or neutral (N).
a) KCIOz
B
b) ((CH3hNHz)NO3
c) Ca(CIO4h
N
d) Ca(CO3)
A
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7) Provide the acid ionization reaction for benzoic acid (see structure above).
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8) Provide the base ionization reaction for the conjugate base of benzoic acid.
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Extra Credit
1) Determine the pH of a 0.25 M solution of selentic acid (HzSeO3)and determine the concentration of Seat
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Ka1= 3.162 x 10-4;Kaz = 7.94 x 10-10
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2) Provide the equation for the reaction that will be the main determinant of the pH in each solution below.
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