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2 Chem 16 Common Sping ch 30, Clculte the ph of queous Stontium hydoxide solution, S OH. Ceful. () 3.7 (b) 3.77 (c).53 (d).3 (e) 9.3 OH x ; poh log ; ph 1 poh.53. The ph of pechloic cid, HClO, solution is.3. Wht is the concenttion of the pechlote ion? () 3.7 x -3 (b) 1.38 x - (c) (d).69 x -1 (e) none of the bove 3. A solution consists of HF, HI, nd 0.05 HCOOH. Wht is the ph? () 1.6 (b) 0.87 (c) 1. (d) 0.3 (e) Insufficient infomtion HF nd HCOOH e wek cids. So, thee concenttions cn be ignoed comped to the stong cid, HI. H 0.055; ph log H 1.6. Wht is the ph of solution fomed by mixing 70. ml of 0.5 NOH nd 10 ml of 0.15 HCl? ().6 (b) 11.5 (c) 1. (d) 1.0 (e) mmol 0.5mol 70mL H q OH q HOl H mmol OH x 17.5mmol ml L 1 I mol 10mL mmol H x 1mmol C ph log L 1 E 3.5mmol 0 ph.3 ph log H. So, H ClO 5. A queous solution of wek cid, HB, hs ph of Clculte, the cid-dissocition constnt. I () 6.71x -6 (b) 6.67x -6 (c) 6.63 x -6 (d) 6.67x -3 (e) none of the bove HB q H O l H3O q B q C -x +x +x E 0.15-x x x ph 3 x H HB H B 3 6 = = 6.71x HB Which of the following compounds, when dissolved in wte, is bsic? ost tnsition metl ions () HCN (b) NCl (c) LiHCOO (d) CH3NH 3 (e) FeI 3 e cidic cidic neutl bsic cidic

3 Chem 16 Common Sping ch 30, Clculte the ph of solution tht is 0. HCN nd 0.70 NCN. HCN: =.79 x - () 9.3 (d) 7.37 (b).16 (e) 11.7 (c) 8.7 p log.79x 9.3 B 0.7 ph p log 9.3 log.16 HB Which of the following buffe solutions best esists chnge in ph s eithe n cid o bse is dded? () 0 ml of 1.0 HCOOH nd 1.0 NHCOO (b) 00 ml of 0.70 HCOOH nd 0.70 NHCOO (c) 50 ml of 1.90 HCOOH nd 1.90 NHCOO (d) 1300 ml of 0. HCOOH nd 0. NHCOO. (e) 150 ml of 0.75 HCOOH nd 0.75 NHCOO. 9. A buffe solution consists of 0.3 HCN nd 0.5 LiCN. A smll mount of HB is dded to the buffe. Which ion is esponsible fo keeping the ph lmost constnt? () Li Neutl ion (b) B Neutl ion (c) H This is wht must be neutlized fo the ph not to chnge. (d) HCN (e) CN Acid does not neutlize cid Conjugte bse neutlizes cid:. Which of the following wek cids o bses is best suited to pepe buffe whose ph is 8.90? () C 6 H 5 OH: p = (b) ClCH COOH: p =.87 (c) HNO : p = 3.35 (d) NH 3 : p b =.76 (e) CH 3 COOH: = 1.76 x -5 0 mmol cid nd bse 10 mmol cid nd bse (lgest) 95 mmol cid nd bse 130 mmol cid nd bse 113 mmol cid nd bse wnt p closest to desied ph o 8.9 p p 5 log 1.76x.75 CN H O HCN H O Wht volume of 0.0 S(OH) completely neutlizes 35 ml 0.30 HCl? Answes e fo 1 sig. fig. () 50 ml (b) 70 ml S OH q HCl q H O l SCl q (c) 300 ml (d) 00 ml (e) 0 ml 0.30mol HCl 0.035L mol S OH L L 1 mol HCl 0.0mol S OH x x x 0.13L130mL

4 Chem 16 Common Sping ch 30, Fo the ection As Bg Cg Dg concenttionunitsomitted, seconds into the ection, thee is some A, 0. moles B, 0.7 moles C, nd 3 moles D in.0 L contine. Wht is the mgnitude of Q nd in which diection does the ection go to ech equilibium? () 3.7 nd to the left (b) 3.7 nd to the ight 0.0mol 0.70mol 3mol B 0.0, C 0.35, D 1.5 L L L (c).6 nd to the ight (d) 0.9 nd to the left C D B Q (e) 0.9 nd to the ight 13. Fo esonble concenttions, which pi of ions would poduce pecipitte in solution contining these ions? () (b) Ti Ti,, Cl Cl Rule : choide, bomide, nd iodide compounds e soluble. (c) Ni (d) Ni (e), I, S NH Rule 5b: CHOPS o cbonte, hydoxide, oxide, phosphte, nd sulfide compounds e insoluble., S Rule 1: sodium, potssium, nd mmonium compounds e soluble. 1. You hve 0.1 solution of ech of the following ionic compounds. Which hs the highest ph?. NF b. NI bsic neutl Wekest cid hs stongest congugte bse. c. OCN bsic 1 b d. LiCN bsic e. NHSO cidic N,, Li e neutl ions 15. hydogen chloide gs is bubbled though wte. The following ection tkes plce: In this ection, wte is. Lewis cid b. n Ahenius cid c. Bonsted-Lowy bse d. conjugte bse e. n Ahenius bse HCl g H O l H O q Cl q 3 becuse it eceives the poton fom HCl.

5 k f Chem 16 Common Sping ch 30, Suppose A B Cis n elementy ection step which is fst, evesible, nd t equilibium. k Initilly, A B 0.1 nd 0.. eq is smll nd [A] << [C] b. eq is smll nd [A] >> [C] c. eq is lge nd [A] << [C] d. eq is lge nd [A] >> [C] e. eq = 1 nd [A] << [C] C Which of the following sttements is coect, if k k? 17. Solid AgCl is dded to the following solutions. Ange fom lest to most soluble fo AgCl. I. Pue wte Use Le Chtelie's Pinciple II. In wte whee lots of solid NCl is dded nd stied Stess--excess Cl. So, xn diven to left, i.e., less soluble. III. In wte whee NH 3 gs ws bubbles though it. Note, complex ion Ag NH3 foms.. I, II, III d. III, I, II Stess--too little Ag. So, xn diven to ight, i.e., moe soluble. b. II, I, III e. II, III, I c. III, II, I 18. Wht is the ppoximte eq fo the ection: HCOOH q OH q H Ol HCOO q given HCOOH q HO l H3O q HCOO q 1.78x the following ections: HOl HOl HO q OH q x 3 w 1. 1 b. 18 c. -9 d. 9 e. 6 C At equilibium, fowd te = evese te o k A B k C. eq k f 1 A B k 3 HCOOH q H O l H O q HCOO q 1.78x 3 HO q OH q HO l HO l ' 1/ 1x HCOOH q OH q H O l HCOO q ' 1.78x f w f ml of 0.1 HCl is dded to 0 ml of 0.07 sodium fomte (NHCOO) nd stied. Wht is the esulting ph? See the pevious poblem fo the of HCOOH...00 b..15 c d e H3O q HCOO H O l HCOOH q I 5mmol 7mmol - 0 C E 0 5 B ph p log 3.75 log 3.35 HB 5 0. Wht is the ph of -9 NOH? () 5 The ph of pue wte is 7. When you hve vey dilute bse, the solution (b) 9 must be slightly bsic, tht is, the ph must be slightly gete thn 7. (c) slightly less thn 7 The coect clcultion includes the OH fom wte becuse the bse (d) exctly 7 concention is so dilute. (e) slightly gete thn 7

6 Pt B ( points) Chem 16 Common Sping ch 30, 015 I. (pts) A buffe with ph = is peped using fomic cid, HCOOH, nd its conjugte bse, HCOO -. If the conjugte bse concenttion is 0.0, wht is the cid concenttion? (p = 3.75). ph B 0. HB p log log 3.75 log HB HB 0. HB HB log ; 1.78; HB 0.71 Fo b nd c: Phosphoic cid is tipotic cid: H 3 PO (q) +H O(l) H 3 O + (q) + H PO - (q) 1 = 7.5 x -3 H PO - (q) +H O(l) H 3 O + (q) + HPO - (q) = 6. x -8 HPO - (q) +H O(l) H 3 O + (q) + PO 3- (q) 3 =.8 x -13 b. ( pts) Wht is the ph of 0.35 solution of phosphoic cid? HPO q HOl HO q HPO q 3 3 I C -x +x +x E 0.35-x x x x ; 0.35 x 3 st 1 x 0.35x 7.5x H ; ph 1. 9 nd Aside, x H ; ph c1. (1 pt) Wht is the when HPO behves s n cid? = 6.x 1 w b 1.3x c. ( pts) Wht is the b when HPO 3 behves s bse? 1 7.5x cidic c3. (1 pt) Is 0.5 NH PO cidic o bsic? Note, thee is no ptil cedit fo pt c. The nswe is eithe full cedit o 0. Futhemoe, thee is no cedit fo c3 without c1 nd c being coect. 1

7 Chem 16 Common Sping ch 30, 015 II. The following questions e independent. So, you don't hve to get the pevious question ight to nswe the next one. () 3PTS The gph to the ight shows the tittion of wek cid with stong bse. Wht is the ppoximte vlue of fo this cid? AT the equivlence point: HB B. B So, ph.7 p log p HB x (1x to 6 x fo cedit) (b) PTS ml of 0.5 HNO 3 is dded to 0 ml of 0.5 mmoni, NH 3. Wht is the ppoximte equilibium concenttion of ech of the following ions? Fo less thn -3, wite 0. Fo exmple, 6 5.x 0 nd 3.7x x. ml 0.5NO3 x NO3 30mL H 0 NH3 0 NH 0.17 o 0. (c) 5PTS Clculte the ph of 0.0 NH Cl. Include the ppopite ection nd ICE tble. b (fo NH 3!!!) is 1.8 x -5. Fill in the ICE tble, including the ection. Rection: Initil: 1 NH q HOl NH3q H3O q w 5.56x 5 b 1.8x Chnge: - x +x +x Equilibium: 0. x x x 5 ph. ph log 1.05x.98 H3O q NH3q H O l NH q I 5 mmol 5 mmol - 0 C E NH mmol 5mmol mL x x ; x 5.56x 0. x 1.05x 0. x 0