Title 4. Che. Engg. Practice Sheet-(2nd Paper) With Solve.pdf ✅

Zwor imvqb  Engineering Practice Sheet ........................................................................................................................ 1 WRITTEN weMZ mv‡j BUET-G Avmv cÖkœvejx 1. Fe2+(0.2 M)/Fe Ges Cu2+(0.1 M)/Cu Gi EMF KZ? [Fe2+/Fe = – 0.44 V, Cu2+/Cu = 0.34 V] [BUET 22-23] mgvavb: Ecell = E0 cell – RT eF ln [Fe2+] [Cu2+] 0C †Z, E 0 cell = E 0 Fe/Fe2+ + E 0 Cu 2+/Cu = 0.44 + 0.34 = 0.78 V 25C †Z, Ecell = 0.78 – 8.314 × 298 2 × 96500 ln [0.2] [0.1] = 0.7711 V 2. wjw_qvg Avqb e ̈vUvwi eZ©gvb mg‡qi Avkve ̈ÄK kw3 mÂq e ̈e ̄’v ̧‡jvi GKwU| e ̈vUvwii cÖgvY Zwo”PvjK e‡ji gvb 3.70 V| †mj wewμqvwU wb¤œiƒc: CoO2 + LiC6  LiCoO2 + 6C e ̈vUvwii Aa©-†Kvl wewμqv wjL| [BUET 21-22] mgvavb: RviY Aa©wewμqv: LiC6  Li+ + 6C + e– weRviY Aa©wewμqv: CoO2 + Li+ + e–  LiCoO2 3. hw` H2SO4 Gi jNy `ae‡Yi ga ̈ w`‡q Pt ZworØv‡ii gva ̈‡g GKwU Zwor we‡køl ̈ †Kv‡l 1 NÈv we`y ̈r cÖevwnZ nq, Zvn‡j STP-†Z 300 mL H2(g) Drcbœ nq| we`y ̈rcÖev‡ni cwigvY wbY©q Ki| [BUET 20-21] mgvavb: n = It eF  PV RT = It eF  I = PV  eF RT  t  I = 1 × 300 1000 × 2 × 96500 0.0821 × 273 × 3600 = 0.72 A (cÖvq) 4. wb‡Pi †KvlwU e ̈env‡ii c~‡e© Gi g‡a ̈ 250 mL 0.35 M CuSO4 `aeY wQj| ev‡j¦i †iva 50  n‡j 20 NÈv e ̈env‡ii ci CuSO4 `ae‡Yi NbgvÎv KZ n‡e? [BUET 19-20] ZnSO4 Solution E 0 Zn/Zn2+ = 0.76V E 0 Cu/Cu2+ = – 0.34V Bulb Zn rod Cu rod CuSO4 Solution mgvavb: V = E = E 0 Zn/Zn2+ + E 0 Cu2+/Cu = 0.76 + 0.34 = 1.1 V V = IR  I = V R = 1.1 50 A = 0.022 A GLb, n = It eF = 0.022  20  3600 2  96500 mol = 8.20725  10–3 mol  CuSO4 `ae‡Yi NbgvÎv Kg‡e| c~‡e© †gvj msL ̈v, n1 = V1 × S1 = 0.250 × 0.35 = 0.0875 mol †gvj n«vm cv‡e = 8.20725 × 10–3 mol  cieZ©x †gvj msL ̈v, n2 = 0.0875 – 8.20725 × 10–3 = 0.07929 mol  cieZ©x NbgvÎv S2 = n2 V = 0.07929 mol 0.250 L = 0.3171 M 5. 200 cm2 †ÿÎd‡ji c„ôZjwewkó GKwU avZe Kv‡ci Dci 0.2 mm cyiæ‡Z¡i iƒcvi cÖ‡jc †`qv cÖ‡qvRb| iƒcvi NbZ¡ 1.05  104 kg/m3 | hw` 12.5 A we`y ̈r cÖevwnZ Kiv nq Zvn‡j D3 cÖ‡jc w`‡Z avZe KvcwU‡K KZÿY B‡jK‡UavjvBwUK U ̈vs‡K ivL‡Z n‡e? [Ag = 107.86 g/mol] [BUET 18-19; BUTex 18-19] mgvavb: Avgiv Rvwb, fi = AvqZb  AvqZb = A  d = 200  10–4  0.2  10–3 = 4  10–6m 3 fi = 4  10–6  1.05  104 = 42 g Avevi, w = MIt eF  42 = 107.86  12.5  t 96500  1  t = 3006.119 s = 50.1 min 6. wRsK †K¬vivBW e ̈vUvwi‡Z wb‡¤œi †Kvl wewμqv Øviv we`y ̈r Drcbœ nq- Zn(s) + Cl2(g)  ZnCl2(aq) RviY Aa© wewμqv, weRviY Aa© wewμqv wjL I cÖgvY †Kvl wefe E 0 cell †ei Ki| cÖgvY weRviY wefe: E 0 Zn++/Zn = – 0.76 V Ges E 0 Cl2 /Cl – = 1.36 V [BUET 18-19] mgvavb: Zn  Zn2+ + 2e– (RviY Aa© wewμqv) Cl2 + 2e–  2Cl – (weRviY Aa© wewμqv) cÖgvY †Kvl wefe = E 0 Zn/Zn2+ + E 0 Cl2 /Cl – = – (– 0.76) + 1.36 = 2.12 V
2 ....................................................................................................................................  Chemistry 2nd Paper Chapter-4 7. wRsK †K¬vivBW e ̈vUvwi‡Z wb‡¤œi †Kvl wewμqv Øviv we`y ̈r Drcbœ nq- Zn(s) + Cl2(g)  ZnCl2(aq) cÖgvY gy3kw3i cwieZ©b (G 0 ) †ei Ki| cÖgvY weRviY wefe: E 0 Zn++/Zn = – 0.76 V and E0 Cl2 /Cl – = 1.36 V [BUET 18-19] mgvavb: E 0 cell = 0.76 + 1.36 = 2.12 V G 0 = – nF E 0 cell = – 2 × 96500 × 2.12 J mol–1 = – 409160 J mol–1 = – 409.16 kJ mol–1 8. Au ZworØv‡ii ga ̈ w`‡q AuCl – 4 Avq‡bi `ae‡Y AcwieZ©bxq Zwor cÖevwnZ Kiv nj| 10 wgwbU ci K ̈v‡_v‡Wi fi 1.314 gm e„w× †c‡j Zwor cÖev‡ni gvb wbY©q Ki| (Au Gi cvigvYweK fi = 197) [BUET 17-18] mgvavb: Au3+ + 3e–  Au I = neF t = 1.314 197  3  96500 10  60 = 3.22 A 9. GKwU †jvnvi wUDe‡K wRsK w`‡q cÖ‡jc w`‡Z n‡e| G m¤úwK©Z wb‡Pi cÖkœ ̧‡jvi DËi `vI| (a) †Kvb avZz K ̈v‡_vW wn‡m‡e e ̈envi Ki‡Z n‡e? (b) †Kvb avZz A ̈v‡bvW wn‡m‡e e ̈envi Ki‡Z n‡e? (c) †Kvb B‡jK‡UavW †_‡K ewnt ̄’ mvwK©‡U B‡jKUab cÖevwnZ n‡e? (d) A ̈v‡bvW-G msNwUZ B‡jK‡UavW wewμqvwU wjL| (e) K ̈v‡_vW-G msNwUZ B‡jK‡UavW wewμqvwU wjL| [BUET 16-17] mgvavb: (a) †jvnvi wUDe K ̈v‡_vW wn‡m‡e e ̈envi Ki‡Z n‡e| (b) wR1⁄4 A ̈v‡bvW wn‡m‡e e ̈envi Ki‡Z n‡e| (c) A ̈v‡bvW †_‡K ewnt ̄’ mvwK©‡U B‡jKUab cÖevwnZ n‡e| (d) A ̈v‡bv‡W RviY: Zn(s)  Zn2+(aq) + 2e– (e) K ̈v‡_v‡W weRviY: Zn2+(aq) + 2e–  Zn(s) 10. wb‡Pi wewμqvwU 298 K ZvcgvÎvq ̄^ZtùzZ© wK bv Zv wbY©q Ki: Co(s) + Fe2+(aq)  Co2+(aq) + Fe(s) †`Iqv Av‡Q, [Co2+] = 0.15 M; [Fe2+] = 0.68 M; E 0 Co2+/Co = – 0.28 V; E 0 Fe2+/Fe = – 0.44 V [BUET 16-17] mgvavb: E 0 cell = Eanode(Ox) + Ecathode(Red) = 0.28 – 0.44 = – 0.16 V Ecell = E 0 cell + 2.303  RT 2F log [Fe2+] [Co2+] = – 0.16 + 0.0592 2 log 0.68 0.15 = – 0.14 V  wewμqvwU ̄^Ztù~Z© bv| 11. Zn/Zn2+ || Cu2+/Cu, EMF KZ n‡e Zv wnmve Ki| G‡ÿ‡Î Zn2+ Gi NbgvÎv 0.10 mol L–1 Ges Cu2+ Gi NbgvÎv 0.05 mol L–1 | 298 K ZvcgvÎvq E 0 Zn/Zn2+ = 0.70 V Ges E 0 Cu/Cu2+ = – 0.34 V| [BUET 15-16] mgvavb: †Kvl wewμqv: Zn(s) + Cu2+(aq)  Zn2+ (aq) + Cu(s) Ecell = E0 cell + 2.303 RT eF log [Cu2+] [Zn2+] = E0 Cu2+/Cu – E 0 Zn2+/Zn + 2.303 RT eF log [Cu2+] [Zn2+] = 0.34 – (– 0.70) + 2.303  8.316  298 2  96500 log 0.05 0.10 = 1.04 + 0.02955  log 0.5 = 1.04 + 0.02955 – 0.301) = 1.04 – 0.0088895 = 1.0311 V 12. wb‡¤œi Zwor ivmvqwbK †Kvlmg~‡ni Aa©‡Kvl wewμqv I mvgwMÖK †Kvl wewμqv †`LvI| (a) Zn / Zn++(aq) | Cl – (aq), Hg2Cl2(s)/Hg (b) Pb/PbSO4(s), H2SO4(aq) | PbO2/ Pb [BUET 14-15] mgvavb: (a) Aa©‡Kvl wewμqv: A ̈v‡bv‡W RviY: Zn  Zn2+ + 2e– K ̈v‡_v‡W weRviY: Hg2Cl2 + 2e–  2Hg + 2Cl – mvgwMÖK †Kvl wewμqv: Zn + Hg2Cl2  2Hg + Zn2+ + 2Cl – (b) Aa©‡Kvl wewμqv: A ̈v‡bv‡W RviY: Pb + H2SO4  PbSO4 + 2e– + 2H+ K ̈v‡_v‡W weRviY: PbO2 + 4H+ +SO2– 4 + 2e–  PbSO4 + 2H2O mvgwMÖK †Kvl wewμqv: Pb + 2H2SO4 + PbO2  2PbSO4 + 2H2O 13. GKwU ZworØv‡i 0.2 mol/dm3 NbgvÎvi HCl Gi Rjxq `aeY e ̈envi Kiv nj| 27C ZvcgvÎvq ZworØviwUi RviY wefe wbY©q Ki| [BUET 13-14] mgvavb: EH = E H – RT F ln [H+ ] GLv‡b, E  H  EH = – 8.314  (273 + 27) 96500  ln [0.2  1] = 0.0416 V 14. 27C ZvcgvÎvq GKwU ZworØv‡i 0.02 mol dm–3 HCl Gi `aeY e ̈envi Kiv nj| ZworØviwUi RviY wefe wbY©q Ki| [BUET 12-13] mgvavb: RviY wewμqv: 1 2 H2 – e –  H + ; E 0 cell = 0 V, n = 1, T = 300 K Ecell = E0 cell – RT eF ln [H+ ] = 0 – 8.314  300 1  96500 ln [0.02] = 0.1011 V
Zwor imvqb  Engineering Practice Sheet ....................................................................................................................... 3 15. GKwU Zwor ivmvqwbK †Kv‡l GKwU †jŠn `ЇK wb‡Kj w`‡q Zwor cÖ‡jcb Ki‡Z n‡e| G m¤úwK©Z wb‡Pi cÖkœ ̧‡jvi DËi `vI| (i) †Kvb avZzwU K ̈v‡_vW wnmv‡e e ̈envi Ki‡Z n‡e? (ii) †Kvb avZzwU A ̈v‡bvW wnmv‡e e ̈envi Ki‡Z n‡e? (iii) †Kvb B‡jK‡UavW †_‡K ewnt ̄’ mvwK©‡U B‡jKUab cÖevwnZ n‡e? (iv) A ̈v‡bvW B‡jK‡UavW Gi wewμqvwU wjL| (v) K ̈v‡_vW B‡jK‡UavW Gi wewμqvwU wjL| [BUET 11-12] mgvavb: (i) †jŠn `Ð (ii) wb‡Kj (iii) A ̈v‡bvW (wb‡Kj `Ð) †_‡K (iv) Ni – 2e–  Ni2+ (v) Ni2+ + 2e–  Ni 16. Kcvi mvj‡d‡Ui Rjxq `ae‡Y ` ̄Ívi P~Y© †hvM Kiv n‡j Kx N‡U? [BUET 10-11] mgvavb: Zn Øviv cÖwZ ̄’vcb wewμqv N‡U: CuSO4 + Zn  ZnSO4 + Cu 17. 50 wgwbU a‡i 0.2 A ̈vw¤úqvi we`y ̈r cÖevwnZ nIqvi 0.2 MÖvg Kcvi Rgv nq| Kcv‡ii ivmvqwbK Zzj ̈ IRb wbY©q Ki| [BUET 09-10] mgvavb: w = ZIt  w It = 0.20 0.20  50  60  Z = 3.33  10–4 g C–1 = 3.33  10–7 kg C–1  ivmvqwbK Zzj ̈ IRb, Z = 3.33  10–7 kg C–1 18. h_v_©Zv wePvi K‡i ev‡K ̈ ÒmZ ̈Ó ev Òwg_ ̈vÓ emvI| M ̈vjfvbvBwRs †jvnvi cvBc‡K cathodic protection cÖ`vb K‡i| [BUET 04-05] mgvavb: wg_ ̈v 19. jNy NaCl `ae‡Yi Zwor we‡køl‡Y Kx cwigvY we`y ̈r cÖev‡ni d‡j 1 NÈv mg‡q Pt K ̈v‡_v‡W cÖgvY Pvc I ZvcgvÎvq 0.112 L H2 Drcbœ n‡e| [BUET 03-04] mgvavb: It = neF  I = PV RT  e  F t = 1  0.112 0.0821  273   96500 3600 = 0.268 A 20. 5 mM Fe2+ m¤^wjZ GKwU `aeY Ce4+ w`‡q UvB‡UaU Kiv n‡jv Ges UvB‡Uak‡bi GK ch©v‡q 1 mM Fe3+ •Zix nj| 25C ZvcgvÎvq Aa©‡KvlwUi B.Gg.Gd EFe2+/Fe3+ wnmve Ki| †`Iqv Av‡Q, E 0 Fe2+/Fe3+ = 0.770 V| [BUET 02-03] mgvavb: E 0 Fe2+/Fe3+ = E0 cell – 0.0591 e log [Fe3+] [Fe2+] = 0.77 – 0.0591 1 log     1 5 = 0.8113 Volt 21. GKwU †jvnvi PvgP‡K K ̈v‡_vW wn‡m‡e e ̈envi K‡i Zwor we‡køl ̈ Ni(NO3)2 je‡Yi ga ̈ w`‡q 5.0 amp we`y ̈r 30 wgwbU a‡i Pvjbv Kiv n‡jv| †jvnvi Pvg‡Pi DcwiZ‡ji †ÿÎdj 7.0 cm2 | †jvnvi Pvg‡Pi Dci me©Î mgvbfv‡e m„ó wb‡Kj cÖ‡j‡ci cyiæZ¡ MYbv Ki| [Ni Gi cvigvYweK fi = 58.7 Ges wb‡Kj cÖ‡j‡ci Av‡cwÿK ̧iæZ¡ = 1.4] [BUET 02-03] mgvavb: It = neF t = weF M  w = MIt eF = 2.74 gm w = V × s = A × d × s s = Av‡cwÿK ̧iæZ¡ = 58.7  5  30  60 2  96500 g = 2.74 g w = Ads  d = w As = 2.74 7  1.4 = 0.28 cm 22. hLb GKwU †jvnvi †c‡iK‡K GKwU bxj Kcvi mvj‡dU `ae‡Yi g‡a ̈ Wzev‡bv nq ZLb †h wewμqv N‡U Zvi bvg wjL Ges wewμqvwU †`LvI| [BUET 01-02] mgvavb: Kcvi mvj‡d‡Ui Kcvi cigvYy †jvnvi cigvYy Øviv cÖwZ ̄’vwcZ nq I Kcv‡ii Zvgv‡U Aat‡ÿc c‡i, GwU GKwU cÖwZ ̄’vcb wewμqv| CuSO4(aq) + Fe(s) = Cu(s) + FeSO4(aq) 23. Rjxq CuSO4 `ae‡Yi ga ̈ w`‡q 0.40 amp we`y ̈r GK NÈv Pwjøk wgwbU a‡i cÖevwnZ Ki‡j 0.80 gm Kcvi Rgv nq| Kcv‡ii Zwor ivmvqwbK Zzj ̈v1⁄4 wbY©q Ki| [BUET 01-02] mgvavb: w = ZIt  Z = w It = 0.8 0.4  {(1  60) + 40}  60 = 3.33  10–4 g/C 24. wb‡¤œi †KvlwUi ZworØvi wewμqv I †Kvl wewμqv ̧wj †`LvI| Hg/Hg2Cl2(s), KCl(aq)||Cu++(aq) /Cu [BUET 00-01] mgvavb: GLv‡b, ZworØviwU n‡jv K ̈v‡jv‡gj ZworØvi| A ̈v‡bv‡Wi wewμqv: 2Hg(l) ⇌ Hg2+ 2 + 2e– Hg2+ 2 + 2Cl – (KCl †_‡K) ⇌ Hg2Cl2 2Hg(l) + 2Cl –  Hg2Cl2(s) + 2e– K ̈v‡_v‡Wi wewμqv: Cu2+(aq) + 2e–  Cu(s) mgMÖ wewμqv: 2Hg(l) + 2Cl – (aq) + Cu2+(aq)  Hg2Cl2(s) + Cu(s)