test_key_2018_ab_applications

AP Chemistry: Test Equilibrium Applications Name k(’t’f Questions 1-2: The graph below shows the titration curve that results when 100. mL of 0.0250 A acetic acid is titrated with 0.100 A/ NaOH. = pH 8.0 W 6.0 -V 4.0 YeF——— o 00 57510 15 20 25 30 35 40 45 mL of 0.100 A NaOH Added 1. (D) Which of the following indicators is the best choice for this titration? pH Range of Indicator Color Change (A) Methyl orange 32- 44 (B) Methyl red 48- 6.0 (C) Bromothymol blue 6.1- 76 (D) Phenolphthalein 82- 10.0 2. (A) What part of the curve corresponds to the optimum buffer action for the acetic acid/acetate ion pair? (A) PointV (B) Point X (C) PointZ (D) Along all of section WY Compound Kgpat298K Agel 1.6 x 10710 AgxCOs 8.1 x 10712 AgCrOy 9.0 x 10712 b0y 1.8x 10718 3. (C) Based on the values in the table above, a saturated solution of which of the following compounds has the highest [Ag+] 2 (A) AgCl (B) Ag:COs (C) Ag:CrOy4 (D) AgsPOq4 g - 12 2. ~12 N / X5 ) bxto N Yxis gdnlo Yx"s 4.0x10 2’ 1. § %00 % - -5 x:[.lfiKID.SM Xz "27Y/04M )(:/.J_/)NoyM x: /.(/XID M Unauthorized copying or reuse of any part of this page is illegal. Go ON TO THE NEXT

Matching A. A solution with a pH less than 7 that is not a buffer solution B. A buffer solution with a pH between 4 and 7 C. A buffer solution with a pH between 7 and 10 D. A solution with a pH greater than 7 that is not a buffer solution E. A solution with a pH of 7 Acid lonization constants: HC,H;0:: K = 1.8x107 H,COs: Ki= 4.0x107 K>=4.0x10" 4.(A) A solution prepared to be initially IM NaCl and 1M HCI 5.(D) A solution prepared to be initially 1M Na,COs and 1M NaC>H;0, 6. (B) A solution prepared to be initially 0.5M HC;H;0, and IM NaC;H;0; 7. (B) Mixtures that would be considered buffers include which of the following? [. 0.10 MHCI+0.10 M NaCl 1. 0.10 M HF +0.10 M NaF 1. 0.10 M HBr+ 0.10 M NaBr (A) Tonly (B) I only (C) Wlonly (D) IlandlIIl 8. (C) In which of the following solutions would CuBr have the highest solubility? (A) 0.ISMKBr commen oo & (B) 0.10MLiBr ¢t¢mmen ron & . - (C) 0.10 M AgNOs /‘19‘ veadls witt Br° —p fl;c/( vemove§ Br~ —> (D) Pure Water 9. (B) A student prepares a buffer by mixing 0.20 mol of HC;H;0 (aq) (Ka = 1.8 x 10-5) with 0.20 mol of KC:H30: (aq). What is the pH after 25 mL of 2.0M NaOH is added? HA o A (A) 4.63 (B) 4.97 ©) 5. o ;D) 5.28 b 2 2% P Ha 4,744 log (&2 AT = 10. (C) In the titration of a weak base of unknown‘concen ratlon w1th a standard solution (of known concentration) of a strong acid, a pH meter was used to follow the progress of the titration. Which of the following is true for this experiment? (A) The pH is 7 at the equivalence point. (B) The pH at the equivalence point depends on the indicator used. (C) The graph of pH versus volume of acid added falls gradually in the buffer range. (D) The pH after the equivalence point is determined by the amount of excess weak base. 11. (A) In a saturated solution of Zn(OH) at 25°C the value of [OH-] is 2.0 x10-6 M. What is the value of the solubility-product constant, Kgp, for Zn(OH)2 at 25°C? (A) 4.0x10"8 (B) 8.0x10'® (€) 1.6x10"7 (D) 4.0 x107'? ksp : [2'\”.] [‘7”-]1' (1.0 xlo"}(l"’ Wfl/l g ox10® " Unauthorized copying or reuse of any part of this page is illegal. GO ON TO THE NEXT