uni chemistry help... need to check answers ... anyone plz ... thanks (plz...

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...provide selection A,B,C, etc..)? A weak monoprotic acid is 0.50% ionized in a 1.0 M solution. The dissociation constant of the weak acid is



a. 5.0 ´ 10-1.

b. 5.0 ´ 10-3.

c. 2.5 ´ 10-5.

d. 2.5 ´ 10-6.

e. 2.5 ´ 10-7.




2.
Calculate the pH of a 0.25 M HF solution that is 5.2% ionized (Ka = 6.8 ´ 10-4).



a. 1.79

b. 1.85

c. 1.89

d. 1.95

e. 1.99




3.
Calculate Kb for the cyanide ion, CN- (the hydrolysis constant). (Ka for HCN = 4.9 ´ 10-10.)



a. 5.6 ´ 10-10

b. 4.0 ´ 10-10

c. 1.0 ´ 10-7

d. 2.0 ´ 10-5

e. 2.0 ´ 109




4. (Points: 1)
What is the pH of a 0.2 M solution of sodium propionate, NaC3H5O2? (For propionic acid, HC3H5O2, Ka = 1.3 ´ 10-5.)



a. 4.9

b. 7.7

c. 9.1

d. 8.4

e. 11.1
 
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