A) Fe B) Al C) P D) OH - 5) Which salt would form an acidic solution when it dissolves in water?

Transcription

1 AP Chemistry Test (Chapters 14 and 15) 1) Which one would hydrolyze water the most? A) NH 4 + B) Cl C) Na + D) ClO 3 2) Which one is most likely to be a Lewis acid? A) Fe B) Al C) P D) OH 3) What is the conjugate acid of H 7 X 3 Z +4? 4) What is the conjugate base of H 7 X 3 Z +4? 5) Which salt would form an acidic solution when it dissolves in water? A) NaCl B) AlCl 3 C) NaC 2 H 3 O 2 D) CaF 2 6) Which salt would form a basic solution when it dissolves in water? A) Na 2 C 2 O 4 B) Mg(CN) 2 C) NH 4 Cl D) KNO 3 7) Which one could not be neutralized (partial or whole) by a weak base? A) HCl B) H 3 PO 4 C) K 2 O (s) in H 2 O D) Zn(OH) 2 E) Cl 2 O 7 (g) in H 2 O 8) Four of the following pairs of acids list the weaker acid on the left and the stronger acid on the right. Which pair is reversed? Weaker Acid Stronger Acid A) HIO 3 HClO 3 B) HClO HClO 2 C) H 3 PO 4 HNO 3 D) H 2 S H 2 Se E) H 3 PO 4 H 3 AsO 4 9) In a sample of pure water, which statement is always true at all conditions of temperature and pressure? A) [H 3 O + ] = 1.0 X 10 7 M B) [OH ] = 1.0 X 10 7 M C) = 7.0 D) poh = 7.0 E) [H 3 O + ] = [OH ] 10) Which one is matched correctly? A) 14; [H + ]>>>>>[OH ] B) 1; [H + ] <<<<<<<[OH ] C) 7; [H + ]>[OH ] D) 8; [H + ]<[OH ]

2 11) Which of these acids is the strongest? A) K a = 4.25 X 10 9 B) K a = 6.25 X 10 3 C) K a = 2.15 X 10 5 D) K a = 3.00 X ) When solid NaCN is added to water, the?. A) remains at 7. B) becomes greater than 7 because the Na + hydrolyzes water. C) becomes less than 7 because the Na + hydrolyzes water. D) becomes less than 7 because the CN hydrolyzes water. E) becomes greater than 7 because the CN hydrolyzes water. Please consider the following graph to answer questions ) Which one best describes the experimental procedure used to obtain these lab results? A) A strong acid was titrated with a weak base. B) A weak acid was titrated with a strong base. C) A strong base was titrated with a weak acid. D) A strong acid was titrated with a strong base. 14) Which one best describes the contents of the beaker at the equivalence point? A) Excess acid, salt & water B) Excess base, salt & water C) Salt & water D) Water E) Excess acid & base 15) Which one is true about point A? A) The base is the limiting reagent. B) The acid is the limiting reagent. C) The beaker contains only salt & water. D) The beaker contains only excess base. E) The beaker contains only excess acid.

3 16) Which graph illustrates a weak base titrated with a strong acid? A) B) C) D) 17) Which is a primary difference between a weak acid/strong base titration curve & a strong acid/strong base titration curve? A) A weak acid/strong base curve has a greater jump at the equivalence point. B) A weak acid/strong base curve has a small jump at the equivalence point. C) A weak acid/strong base curve has the equivalence point at = 7. D) A strong acid/strong base curve illustrates the hydrolysis of water. 18) Which one is arranged from the strongest to the weakest base? HOCl Ka = 3.5 X 10 8 NH 3 Kb = 1.8 X 10 5 A) H 2 O, NO 3, OCl, NH 3 B) OCl, NH 3, H 2 O, NO 3 C) NO 3, H 2 O, NH 3, OCl D) NH 3, OCl, H 2 O, NO 3 E) OCl, NH 3, NO 3, H 2 O 19) Water has Kw = 1.26 X at 60 o C. What is the of water at 60 o C? A) 7.00 B) 6.45 C) 7.55 D) ) Which one is matched correctly? A) NH 3 = 8 B) H 3 PO 4 = 1 C) HC 2 H 3 O 2 = 10 D) Ca(OH) ) Which one is false about an acid? A) The larger the Ka, the lesser the dissociation in water. B) The larger the Ka, the larger the dissociation in water. C) The larger the Ka, the lower the. D) The larger the Ka, the stronger the acid.

4 Please use the following reaction to answer questions Al(H 2 O) H 2 O H 3 O + + Al(H 2 O) 5 (OH) 2+ 22) Which species is the conjugate base? 23) Which species is the acid? 24) Which statement is correct? A) Strong acids have strong conjugate bases. B) Weak bases have strong conjugate acids. C) Weak bases have strong conjugate bases. D) Strong acids have weak conjugate acids. 25) Please consider the conjugal pair HPO 4 2 /H 2 PO 4 in water. Which statement is true? A) The HPO 2 4 is a base that took an H + from water. B) The H 2 PO 4 is the conjugate base. C) The HPO 2 4 is an acid that took an H + from water. D) The HPO 2 4 is a base that donated an H + to the water. 26) Which one is a polyprotic acid? A) HF B) HNO 3 C) HClO D) H 3 PO 4 27) Which pair could be a buffer? A) HNO 3 /NO 3 B) Ba(OH) 2 /Ba 2+ C) HClO/ClO D) Al(OH) 3 /OH E) NaCl/Cl 28) What is the purpose of a buffer? A) To absorb the conjugate base of an acid B) To absorb H + and OH C) To absorb the conjugate acid of a base D) To absorb salts 29) Please consider the combination of HClO 4 and NaClO 4 in water. Which one is true? A) It is not a buffer because it cannot absorb H +. ` B) It is not a buffer because it absorbs OH. C) It is a buffer because it absorbs H +. D) It is a buffer because it absorbs OH. 30) Which one is false about indicators? A) They are weak organic acids. B) The acid and conjugate base exist as different colors. C) They utilize LeChatelier s principle to shift from one color to another. D) They change when pka of the indicator = of the acid or base used in the titration.

5 31) Which indicator would be most useful in a titration where the equivalence point was approximately 6? A) Bromophenol blue yellow 4 blue B) Bromcresol purpler yellow 6 purple C) Phenolphthalein clear 9 fuschia D) Bromothymol blue yellow 7 blue Please write a net ionic reaction for each of the following. 32) Sodium acetate is added to water. 33) Dichlorine heptoxide gas is bubbled through water. 34) Solid aluminum oxide is added to water. Please consider this buffer: HC 2 O 4 H + + C 2 O 4 2 for ) Please write the reaction that occurs when an acid H + is added to this buffer. 36) Please write the reaction that occurs when a base OH is added to this buffer. Please consider this buffer: CH 3 NH 2 + H 2 O CH 3 NH OH for ) Please write the reaction that occurs when an acid H + is added to this buffer. 38) Please write the reaction that occurs when a base OH is added to this buffer.