Which of the following describes the net ionic reaction for the hydrolysis. Which of the following salts will produce a solution with the highest ph?

Transcription

1 95. Which of the following descries the net ionic rection for the hydrolysis of NH4Cl( s)? A. NH4 ( q) Cl & ( q) NH4Cl( s) B. NH Cl & 4 ( s) NH4 ( q) Cl ( q) C. Cl ( q) H O & 2 ( l) HCl( q) OH ( q) D. NH4 ( q) H2O & ( l) NH ( q) HO ( q) 96. Which of the following slts will produce solution with the highest ph? A. 0 M NNO B. 0 M NHSO4 C. 0 M NHCO D. 0 M NH2PO4 97. A sustnce which produces hydroxide ions in solution is definition of which of the following? A. n Arrhenius cid B. n Arrhenius se C. BrønstedLowry cid D. BrønstedLowry se 98. Which of the following is generlly true of cids, ut not for ses? A. ph > 7 B. relese H in solution C. conduct current when in solution D. cuse indictors to chnge colour 99. Which of the following 0 M solutions will hve the highest electricl conductivity? A. HI B. HF C. HCN D. HNO 2

2 10 Consider the following equilirium: HOI F " OI HF Rectnts re fvoured in this equilirium. Which of the following descries the reltive strengths of the cids nd the ses? Stronger Acid Stronger Bse A. HF F B. HF OI C. HOI F D. HOI OI Which of the following is true for neutrl queous solution? A. [ HO ]= 00. M [ ]= [ ] [ ]> [ ] [ ]< [ ] B. H O OH C. H O OH D. H O OH Which of the following is definition of p w? A. p =log w B. pw = ph poh C. p 7. 0 t 25 C w = D. p H O OH w w = [ ][ ] 10. Consider the following equilirium: 2 ( q) 2 ( l ) ( q) q H CO H O ( H O HCO Wht is the equilirium expression? [ HO ][ HCO ] A. = H CO B. = [ 2 ] [ H2CO] HO HCO [ ][ ] [ H CO ][ H O ] C. = 2 2 HO HCO [ ] [ ] [ HO ][ HCO ] D. = H CO H O [ 2 ][ 2 ]

3 104. Which of the following descries the net ionic eqution for the hydrolysis of NNO 2 solution? A. NNO ( N NO 2 s q 2 q B. NO2 ( q) H2O ( ( l) HNO2( q) OH ( q) C. N( q) 2H O ( 2 ( l ) H O ( q) NOH( q) D. NNO2( s) H2O ( ( l) NOH( q) HNO2( q) 105. The HC O 2 4 q ion will ct s A. se since < B. se since > C. n cid since < D. n cid since > 106. Which of the following is property of ll cidic solutions t 25 C? A. They hve ph less thn 7. B. They hve ph greter thn 7. C. They cuse phenolphthlein to turn pink. D. They relese hydrogen when plced on copper metl When smll solid smple is dded to solution of H2SO4, precipitte forms nd the solution ecomes less cidic. Which of the following sustnces could hve cused these results? A. N2SO4 B. Sr OH C. Mg OH 2 C. Mg( OH) Consider the following rection: 2 D. C NO 2 2 HCN CH NH $ CN CH NH Which of the following descries conjugte cidse pir in the equilirium ove? Acid Bse A. CN HCN B. CHNH CN C. HCN CHNH D. CHNH CH NH 2

4 109. Which of the following is the wekest se? A. F B. HS C. CN D. IO 11 Which of the following reltionships is used to clculte w t 0 C? A. w = ph poh w = [ ] w = [ ][ ] w = [ ] [ ] B. p log HO C. H O OH D. H O OH 11 Wht is the poh of 2 M HNO? A B. 2 C. 7 D Which of the following vlues represents the cid with the strongest conjugte se? A. = B. = C. = D. = Wht is the dissocition eqution for N2CO in wter? 2 2 s q q A. N2CO% N CO B. N CO % 2N CO 2 2 s q q 2 C. CO ( q) H2O( l) % HCO ( q) OH ( q) D. N2CO( s) 2H2O( l) % 2NOH( q) H2CO ( q) 114. Which of the following solutions hs the highest ph? A. 1M HCl B. 1M NF C. 1M NHS D. 1M NH4Cl

5 WRITTEN PROBLEMS Consider the following BrønstedLowry equilirium: 2 q q 2 4 q q H2SO HPO 4 H PO HSO ) Identify the two BrønstedLowry cids in the ove equilirium. ) Define the term conjugte cid. 2. Consider the following equilirium: energy H O H O OH 2 2 ) Explin how pure wter cn hve ph = 7. ) Clculte the vlue of w for the smple of wter with ph = ) Write the eqution for the predominnt rection of HC O 2 4 with HSO. 2 4 HC O HSO cid se ) Identify BrønstedLowry conjugte cid se pir from the ove rection. Acid: Bse: [ ] 0 50 Clculte the OH in. M NH q. Write the eqution for the predominnt rection etween HSO 4 nd H PO 2 4. A 20 M solution of wek cid, HA, hs ph = 2. Use clcultions nd the tle of Reltive Strengths of BrønstedLowry Acids nd Bses from the Dt Booklet to determine the identity of the cid. Clculte the ph of solution prepred y mixing ml of 50 M HCl with 5. 0 ml of 0 M NOH. 8. Consider 0 M solution of NH 4 F. ) Write oth hydrolysis rections tht occur when NH F 4 is dissolved in wter. ) Will the ove NH F 4 solution e cidic, sic, or neutrl? Support your nswer with clcultions.

6 9. Consider the 10 M solutions of the following two cids: Acid HA Acid HB 10 M 10 M ph = 00 ph = 2.87 ) Wht cn you conclude out the cids tht will explin these different ph vlues? ) Compre the volume of 10 M NOH needed to neutrlize equl volumes of ech of these cid smples. 1 Will HC O 2 4 ct predominntly s n cid or s se in solution? Support your nswer with clcultions. 1 The two rectnts in n cidse rection re HNO 2( q) nd HCO ( q). ) Write the eqution for the ove rection. ) Define the term conjugte cidse pir. c) Write the formuls for conjugte cidse pir for the ove rection. 12. At 1 0 C, = w for pure wter. ) Clculte the ph of wter t 1 0 C. 14. At prticulr temperture 0 M H2S solution hs ph =. 75. Clculte the vlue of t this temperture. The ion H PO 2 4 is n mphiprotic nion. ) Define the term mphiprotic. ) Write the lnced eqution for the rection when H PO 2 4 rects with HF Write n eqution for rection in which H O 2 cts only s BrønstedLowry se. Clculte the ph of 25 M Sr( OH) 2. Clculte the ph of 25 M NH4Cl.

7 18. The cynide ion, CN, is BrønstedLowry se. ) Define BrønstedLowry se. ) Write the eqution representing the rection of CN with wter. c) Identify conjugte pir in ) ove. 19. Write n eqution to show the ioniztion of wter. 2 2 Clculte the ph of 50 M NH. Consider the following equiliri: I. CH COOH OCN HOCN CH COO II. CH COOH ClO HClO CH COO ) In eqution I ove, the rectnts re fvoured. Identify the stronger cid. ) In eqution II ove, the products re fvoured. Identify the stronger cid. c) Consider the following rection: HOCN ClO OCN HClO Does this rection fvour rectnts or products? Explin At 60 C, the ph = for pure wter. Determine the vlue of w t this temperture. Clculte the ph of 5 M H2CO. Write chemicl rection showing n mphiprotic nion recting s se in wter. An cidse rection occurs etween HSO nd IO. ) Write the eqution for the equilirium tht results. ) Identify one conjugte cidse pir in the rection. c) Stte whether rectnts or products re fvoured, nd explin how you rrived t your nswer. 26. At 10 C, = w. ) Determine the ph of wter t 10 C. ) Stte whether wter t this temperture is cidic, sic or neutrl, nd explin.

8 Clculte the ph of 50 M H2S. ) Write n eqution to represent the predominnt rection when HC O 2 4 is mixed with HSO 4. ) Justify your sttement y compring vlues. c) Identify conjugte cidse pir. d) Predict whether the equilirium will fvour the formtion of rectnts or products. Explin. Write n eqution representing the ioniztion of wter nd stte oth ion concentrtions tht exist for pure wter to hve ph = Clculte the ph of 25 M NHCO, sic slt. Write the net ionic eqution for the cidse rection tht occurs etween NCN ( q) nd NH4Cl( q). Define the term mphiprotic nd give n exmple of n mphiprotic nion.. 4. At 20 C, the ioniztion constnt of wter w Clculte the H O Clculte the ph of [ ] of wter t 20 C. 50 M NF. is

9 MULTIPLE CHOICE ANSWERS 1 C 6 C 11 C 16 B 21 D 26 C 1 B 6 D 41 D 46 C 2 C 7 B 12 C 17 A 22 D 27 B 2 B 7 A 42 A 47 D A 8 D 1 B 18 B 2 B 28 C B 8 B 4 B 48 C 4 A 9 C 14 A 19 A 24 A 29 A 4 D 9 A 44 B 49 B 5 B 10 B 15 A 20 C 25 C 0 C 5 B 40 C 45 B 50 C 51 C 56 B 61 B 66 D 71 C 76 B 81 B 86 A 91 C 96 C 52 C 57 D 62 C 67 D 72 C 77 B 82 D 87 B 92 D 97 B 5 C 58 B 6 B 68 A 7 A 78 A 8 C 88 B 9 C 98 B 54 B 59 D 64 A 69 B 74 C 79 C 84 A 89 C 94 A 99 A 55 D 60 B 65 A 70 D 75 B 80 B 85 A 90 C 95 D 100 B 101 B 106 A 111 D 102 A 107 B 112 A 10 A 108 D 11 B 104 B 109 D 114 C 105 D 110 C WRITTEN ANSWERS ) For Exmple: ) For Exmple: Species 1: Species 2: H SO mrk H2PO4 1 2 mrk A conjugte cid is species produced when proton is ccepted y BrønstedLowry se. 1 mrk

10 2. ) ) A lower temperture cuses shift to the left. The HO [ ] drops s result, nd the ph increses [ ]= [ ]= = 2mrks H O OH M 1 mrk w = [ ] [ ]= ( )( ) = H O OH mrk. ) 2 HC2O4 HSO C2O4 H2SO se cid 1 mrk ) HC O cid se OR HSO C2O4 H2SO se cid 1 mrk 4. w 0 10 = = = mrk 2 4 NH H O NH OH [] I [ C] x x x [ E] 50 x x x [ NH ][ OH ] 4 = = NH [ ] Use ssumption tht 50 x 50 or use the qudrtic formul. x = [ OH ]= ( x)( x) 50 x = M mrks 2 mrks HSO H PO SO H PO 2 mrks 4

11 6. ph = 2 [ HO ]= 048 M 1 mrk [] I HA H O H O A [ C] [ E] [ HO ][ A ] = HA 2 [ ] The cid is: H SO = = 2 mrks 1 mrk 1 mrk 7. moles HCl = 0150L 50M = mol moles NOH = 050L 0M = mol 2 2 excess moles NOH = mol mol = mol [ NOH]= [ OH ]= 0 10 [ HO ]= 55 ph = mol 050 L 14 = = 55 M 4mrks 8. ) ) NH4 ( q) H2O ( l) NH ( q) HO ( q) F ( q) H2O ( l) HF( q) OH ( q) for NH for F w 0 10 = = Since >, the solution is cidic = = mrk 1 mrk 2 mrks 9. ) Acid HA is strong. ) Acid HB is wek. The sme volume of NOH q is needed for ech cid smple.

12 1 w 0 10 = = = mrks Since = which is greter thn, the ions ct s n cid mrks 1 ) ) HNO2( q) HCO ( q) H2CO ( q) NO2 ( q) 2 mrks A conjugte cidse pir re two species whose formuls differ y proton HNO2 nd NO 2 OR H CO nd HCO H O OH Since [ HO ]= [ OH ] w = 15 = [ ][ ] 1 mrk c) [ HO ] = [ HO ]= ph = M 1 mrk 1 mrk H S H O H O HS 2 2 [] I [ C] [ E] mrks ph =. 75 [ HO ]= M [ H O ][ HS ] ( ) = = HS [ 2 ] = mrks

13 14. ) ) Amphiprotic descries the ility to ct s n cid in one rection nd s se in different rection. 1 mrk H PO HF H PO F 2 mrks HSO H O H O SO 2 mrks 2 [ OH ]= 50 M poh = 0 [] I ph = NH H O H O NH [ C] x x x [ E] 25 x x x 2 mrks 2 mrks 18. ) [ H O ][ NH ] 10 = = NH x = [ HO ]= [ 4 ] 5 ph = 4. 9 A BrønstedLowry se is proton cceptor. M x x = 25 x mrks 1 mrk ) CN H O 2 HCN OH 2 mrks c) CN nd HCN OR H2O nd OH 1 mrk 19. H O H O ( q) OH ( q) 2 mrks 2 2 l NH H O NH OH [] I [ C] x x x [ E] 50 x x x 2 mrks 0 10 = [ ][ ] = mrk

14 [ NH ][ OH ] 4 = NH = x 50 x x = [ OH ]= poh = ph = 1 71 [ ] 2 2 mrks 2 ) ) HOCN CH COOH 1 mrk 1 mrk c) Products re fvoured ecuse HOCN is stronger cid thn HClO. ph = [ HO ]= M =[ OH ] = [ ][ ]= (. )(. ) =. H O OH w [] I H CO H O " H O HCO [ C] x x x [ E] 5 x x x % 2 mrks ) ' mrks mrks 24. [ HO ][ HCO ] = = H CO x = [ HO ]= ph =. 41 [ 2 ] = x 5 x 2 4 M 7 ' mrks 2 HPO H O # H PO OH 2 mrks

15 25. ) 2 HSO IO Æ SO HIO 1mrk (equilirium rrow required) ) c) 26. ) 2 HSO nd SO OR IO nd HIO Rectnts re fvoured. HSO is weker cid thn HIO OR IO 2 is weker se thn SO 15 w = =[ ][ ] H O OH Since [ HO ]= [ OH ], [ HO ] = [ HO ]= ph = mrk 1 mrk 1 mrk 1mrk 1mrk 1mrk ) Since [ HO ]= [ OH ], the wter is neutrl. 1mrk 27. H S H O Æ H O HS 2 2 [] I [ C] [ E] 50 x 50 x 0 x x 0 x x (ssume x is negligile) mrk [ H O ][ HS ] 8 = = HS x = [ HO ]= ph =. 67 [ 2 ] 4 x x = 50 1 mrk 1mrk 12 mrk 28. ) ) c) d) HC O HSO Æ H C O SO 1mrk HSO OR > HC O 1mrk HSO 4 nd SO 4 2 HC O 2 4 nd H C O Rectnts re fvoured since HSO < H C O 2mrks mrk

16 29. H2O( l) H2O( l) Æ HO ( q) OH ( q) 1mrk 8 Since ph = 7. 20, [ H O ]= M 1mrk [ ]= [ ]= 8 H O OH M 1mrk 2 2 HCO H O Æ H CO OH [] I [ C] x x x [ E] 25 x x x (ssume x is negligile) 0 10 = = x 25 x 14 OH 7 [ H CO ][ OH ] 2 = HCO = [ ] =. 2 poh = ph = [ ] M 1 mrk 1 mrk 1 mrk 1 mrk 1 mrk 2.. CN ( q) NH % 4 ( q) HCN( q) NH ( q) Definition: Amphiprotic descries sustnce tht cn ct s either n cid or se. Exmple: HCO H O OH 15 w = [ ][ ] = [ ]= [ ] [ ] = 2 15 Since H O OH, H O [ HO ] = M 2 mrks " 2 mrks 1mrk 1mrk

17 4. [] I 2 F H O # HF OH [ C] x x x [ E] 50 x x x (ssume x is negligile) w 0 10 = = = x 50 4 [ HF ][ OH ] 11 = = F 2 6 x = [ OH ]= [ ] M ' 1 mrk ' 1 mrk 1 mrk 1 mrk poh ph = = ' 1 mrk