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

Zwor imvqb  Varsity Practice Sheet ............................................................................................................................... 1 MCQ weMZ mv‡j DU-G Avmv cÖkœvejx 1. MwjZ CaCl2 Gi ga ̈ w`‡q 1 F Zwor Pvjbv Ki‡j K ̈v‡_v‡W KZ MÖvg Ca avZz Rgv n‡e? [DU 23-24] 20.0 g 40.0 g 80.0 g 35.5 g DËi: 20.0 g e ̈vL ̈v: Q = neF  Q = WeF M  W = QM eF = 1 F × 40 2 × F = 20 g 2. Zn2+/Zn Ges Ag+ /Ag ZworØvi `ywUi weRviY wefe h_vμ‡g – 0.76 V Ges + 0.80 V| GB ZworØvi `ywU Øviv •Zwi †Kv‡li †gvU wefe KZ n‡e? [DU 22-23,12-13; JU 09-10; RU-C 21-22, 08-09, 09-10; MBSTU 16-17; CoU 19-20] – 0.04 V + 1.56 V 0.04 V – 1.56 V DËi: + 1.56 V e ̈vL ̈v: Zn (s)/Zn2+(aq) | Ag+ (aq)/Ag(s) Zn ZworØvi Z_v A ̈v‡bv‡W RviY I Ag ZworØvi Øviv K ̈v‡_v‡W weRviY N‡U| E 0 cell = A ̈v‡bv‡Wi RviY wefe + K ̈v‡_v‡Wi weRviY wefe = Eanode(ox) + Ecathode(red) = {– (– 0.76) + 0.80} = + 1.56 V 3. †Wwb‡qj †Kv‡l †h mKj avZz B‡jK‡UavW wn‡m‡e e ̈eüZ nq Zv n‡jvÑ [DU 21-22;CU-A 20-21, 09-10, 08-09, 03-04, 01-02; HSTU 17-18] Cu and Mg Cu and Zn Zn and Pb Pb and Cu DËi: Cu and Zn e ̈vL ̈v: †Wwb‡qj †Kv‡l B‡jKUa‡bi cÖevn N‡U Zn ZworØvi †_‡K Cu ZworØv‡ii w`‡K| A_©vr, A ̈v‡bvW wn‡m‡e Zn `Ð Ges K ̈v‡_vW wn‡m‡e Cu `Ð e ̈eüZ nq| 4. NaCl Gi mv‡_ H2O †hvM Ki‡j †KvbwU N‡U? [DU 20-21, 15-16; BSMRSTU 18-19] Na+ (aq) + Cl – (aq) NaOH(aq) + HCl(aq) OH+ (aq) + Cl – (aq) Na+ + Cl – DËi: Na+ (aq) + Cl – (aq) e ̈vL ̈v: NaCl(s) + H2O(l)  Na+ (aq) + Cl – (aq) 5. wb‡Pi †Kvb ZworØviwUi cÖgvY weRviY wef‡ei gvb me‡P‡q Kg? [DU 20-21] H + (aq)/H2(g),Pt Cu2+(aq)/Cu(s) Na+ (aq)/Na(s) Pt(s)/F(g)/F– (aq) DËi: Na+ (aq)/Na(s) e ̈vL ̈v: Zwor ivmvqwbK wmwi‡R †h avZzi mwμqZv hZ †ewk †mwU mwμqZv wmwi‡R Dc‡i Ae ̄’vb K‡i Ges Zvi cÖgvY weRviY wef‡ei gvb ZZ Kg nq| Na Gi mwμqZv †ewk nIqvq Gi cÖgvY weRviY wef‡ei gvb me‡P‡q Kg| 6. Fe(s)/Fe2+(aq) || Br2(l)/Br– (aq), Pt(s) Zwor ivmvqwbK †Kv‡li mwVK †Kvl-wewμqv †KvbwU? [DU 19-20] Fe + Br2  Fe2+ + 2Br– Fe + 2Br–  Fe2+ + Br2 Fe2+ + Br2  Fe + 2Br– Fe + Br2  Fe3+ + 2Br DËi: Fe + Br2  Fe2+ + 2Br– e ̈vL ̈v: A ̈v‡bv‡W wewμqv: Fe – 2e–  Fe2+ (RviY Aa©-wewμqv) K ̈v‡_v‡W wewμqv: Br2 + 2e–  2Br– (weRviY Aa©-weμqv) †Kvl wewμqv: Fe + Br2  Fe2+ + 2Br– 7. CuSO4 Gi Rjxq `ae‡Y 0.5 A ̈vw¤úqvi Zwor cÖevn 10 wgwbU hver Pvjbv Ki‡j Kx cwigvY Kcvi Rgv n‡e? [DU 18-19] 0.0987 g 0.0897 g 0.0798 g 0.0789 g DËi: 0.0987 g e ̈vL ̈v: It = neF  It = WeF M  W = MIt eF = 63.5  0.5  10  60 2  96500 = 0.0987 g GLv‡b, MCu = 63.5 t = 10 min = (10 × 60) sec e = 2
2 ....................................................................................................................................  Chemistry 2nd Paper Chapter-4 8. †Kvb jeY Mvp mvjwdDwiK Gwm‡Wi mv‡_ wewμqv K‡i mvjdvi •Zwi K‡i? [DU 18-19] NaF NaCl NaBr NaI DËi: NaF e ̈vL ̈v: RviY Aa©wewμqv: 2F– – 2e–  F2 weRviY Aa©wewμqv: H2 +6 SO4 + 6e–  0 S 9. wb‡Pi †KvbwU M ̈vjfvwbK †mj Zn(s)/Zn2+(aq)||Cu2+(aq)/Cu(s) Gi wefe evovq? [DU 18-19] increase in [Zn2+] increase in [Cu2+] increase in [Zn2+] and [Cu2+] equally increase in [Zn2+] and decrease in [Cu2+] DËi: increase in [Cu2+] e ̈vL ̈v: Zn/Zn2+ || Cu2+/Cu †Kvl wewμqv: Zn + Cu2+  Zn2+ + Cu bvb©÷ mgxKiY g‡Z, Ecell = E0 cell + 2.303RT eF log wewμqK Avq‡bi NbgvÎv [Cu2+] Drcv` Avq‡bi NbgvÎv [Zn2+] GLv‡b, Cu2+ Gi NbgvÎv e„w× †c‡j †Kvl wefeI e„w× cv‡e| 10. MwjZ NaCl Gi ga ̈ w`‡q 1 F Zwor Pvjbv Ki‡j K ̈v‡_v‡W RgvK...Z Na Gi cwigvY n‡”QÑ [DU 17-18, 08-09] 2.3 g 23.0 g 46.0 g 11.5 g DËi: 23.0 g e ̈vL ̈v: Q = neF  Q = WeF M  W = QM eF = 1 F × 23 1 × F = 23 g 11. B‡j‡±av‡KwgK ̈vj †mj †bv‡Uk‡bi †ÿ‡Î wb‡Pi †KvbwU mwVK? [DU 17-18] Zn2+(aq)/Zn(s) || Cu(s)/Cu2+(aq) Zn(s)/Zn2+(aq) || Cu2+(aq)/Cu(s) Zn2+(aq)/Zn(s) || Cu2+(aq)/Cu(s) Zn2+(aq)/Zn(s) || Cu+ (aq)/Cu2+(aq) DËi: Zn(s)/Zn2+(aq) || Cu2+(aq)/Cu(s) e ̈vL ̈v: †Kvl Dc ̄’vc‡bi mvaviY wbqg: A ̈v‡bvW/A ̈v‡bvW `aeY || K ̈v‡_vW `aeY/K ̈v‡_vW AwaK mwμq †gŠjwU A ̈v‡bvW wn‡m‡e e ̈eüZ nq| Zwor ivmvqwbK mvwi‡Z Zn2+ Gi Ae ̄’vb Dc‡i nIqvq Gi weRviY wefe Cu2+ n‡Z Kg ZvB Cu2+ Gi weRviY NU‡e Ges Zn Gi RviY NU‡e| 12. Zn(s)/Zn2+(aq) || Cu2+(aq)/Cu †Kv‡li A ̈v‡bvW I K ̈v‡_v‡Wi cÖgvY weRviY wefe h_vμ‡g – 0.76 V I 0.34 V n‡j †KvlwUi cÖgvY wefe n‡eÑ [DU 17-18; RU 16-17; GST 22-23; BSMRSTU 13-14] 1.10 V – 1.10 V 0.42 V – 0.42 V DËi: 1.10 V e ̈vL ̈v: †KvlwUi cÖgvY wefe, E 0 cell = Eanode(ox) + Ecathode(red) = {– (– 0.76) + 0.34} = 1.10 V 13. NaCl Gi Rjxq `ae‡Yi Zwor we‡køl‡Y †KvbwU Drcbœ nq bv? [DU 15-16] Na Cl2 H2 NaOH DËi: Na e ̈vL ̈v: NaCl(aq)  Na+ (aq) + Cl – (aq) H2O(l) ⇌ H + (aq) + OH– (aq) K ̈v‡_v‡W weRviY: 2H+ (aq) + 2e–  H2(g) A ̈v‡bv‡W RviY: 2Cl – (aq) – 2e– Cl2(g) `ae‡Y msNwUZ wewμqv: Na+ (aq) + OH– (aq)  NaOH(aq) myZivs, NaCl Gi Rjxq `ae‡Yi Zwor we‡køl‡Y NaOH, H2 M ̈vm I Cl2 M ̈vm Drcbœ nq| wKš‘ Na avZz Drcbœ nq bv| 14. Zwor-ivmvqwbK †Kv‡li më-wea‡R †Kvb je‡Yi m¤ú„3 Rjxq `aeYwU DrK...ó? [DU 15-16] KNO3 KI KBr KCl DËi: KCl e ̈vL ̈v: jeY †mZzi g‡a ̈ Zwor we‡køl ̈ wn‡m‡e KCl ev KNO3 ev NH4NO3 ev Na2SO4 e ̈envi Kiv nq| Z‡e KCl `aeYwU me‡P‡q DrK...ó| 15. CuSO4 `ae‡Y 1.0 F we`y ̈r PvR© cÖevwnZ Ki‡j KZ †gvj Kcvi Rgv n‡e? [DU 14-15] 0.5 mole at cathode 0.5 mole at anode 2 mole at anode 2 mole at cathode DËi: 0.5 mole at cathode e ̈vL ̈v: K ̈v‡_v‡W weRviY wewμqv: Cu2+(aq) + 2e–  Cu(s) 2 F we`y ̈r cÖev‡n Cu Rgv nq = 1 mole  1 F we`y ̈r cÖev‡n Cu Rgv nq = 0.5 mole 16. GKwU Kcvi (II) `ae‡Yi ga ̈ w`‡q Aa© NÈv hveZ 10.0 Ampere we`y ̈r cÖevwnZ Ki‡j Kx cwigvY Kcvi mwÂZ ev `aexf~Z n‡e? [DU 13-14, 06-07] 6.3 g 1.5 g 0.60 g None DËi: None e ̈vL ̈v: W = MIt eF = 63.5  10  30  60 2  96500 = 5.92 g
Zwor imvqb  Varsity Practice Sheet .............................................................................................................................. 3 17. H2O2 †K MnO– 4 Øviv RviY Kiv n‡j †Kvl wefe, E 0 cell wnmve Ki| Aa©-wewμqv ̧‡jv n‡jv: [DU 13-14] 2H+ + O2 + 2e– ⇌ H2O2; E = + 0.68 V MnO– 4 + 8H+ + 5e– ⇌ Mn2+ + 4H2O; E = + 1.51 V E 0 cell = – 0.83 V E 0 cell = + 1.51 V E 0 cell = + 0.38 V E 0 cell = + 2.19 V DËi: mwVK DËi †bB| e ̈vL ̈v: GLv‡b MnO– 4 RviK e‡j H2O2 weRviK wn‡m‡e KvR K‡i| †h‡nZz weRvi‡Ki RviY nq Ges Rvi‡Ki weRviY N‡U ZvB H2O2 A ̈v‡bvW Ges MnO– 4 K ̈v‡_vW wn‡m‡e KvR K‡i| A ̈v‡bv‡W RviY wewμqv: H2O2 ⇌ 2H+ + O2 + 2e– ; Eanode(ox) = – 0.68 V K ̈v‡_v‡W weRviY wewμqv: MnO– 4 + 8H+ + 5e– ⇌ Mn2+ + 4H2O; Ecathode(red) = + 1.51 V E 0 cell = Eanode(ox) + Ecathode(red) = (– 0.68 + 1.51) V = + 0.83 V 18. Sn(s) + 2Ag+ (aq)  Sn2+(aq) + 2Ag(s); wewμqvwUi †ÿ‡Î wb‡¤œi †KvbwU †Kv‡li voltage e„w× Ki‡e? [DU 12-13] increase in the size of silver rod increase in the concentration of Sn2+ ions increase in the concentration of Ag+ ions increase in the size of tin rod DËi: increase in the concentration of Ag+ ions e ̈vL ̈v: Sn(s) + 2Ag+ (aq)  Sn2+(aq) + 2Ag(s) bvb©÷ mgxKiY g‡Z, Ecell = E0 cell + 2.303RT eF log [Ag+ ] 2 [Sn2+] mgxKiY †_‡K eySv hvq †h, [Ag+ ] Gi NbgvÎv e„w× Ki‡j †Kv‡li Ecell ev Voltage e„w× cv‡e| 19. wb‡¤œi RviY-weRviY wewμqvwU †h Zwor‡Kv‡l N‡U †mwUi †Kvl ms‡KZ †KvbwU? [DU 11-12, 05-06] CuSO4(aq) + Zn(s)  Cu(s) + ZnSO4(aq) Cu(s)/CuSO4(aq) | ZnSO4(aq) + Zn(s) CuSO4(aq)/Cu(s) | ZnSO4(aq)/Zn(s) ZnSO4(aq)/Zn(s) | CuSO4(aq)/Cu(s) Zn(s)/ZnSO4(aq) | CuSO4(aq)/Cu(s) DËi: Zn(s)/ZnSO4(aq) | CuSO4(aq)/Cu(s) 20. †μvwgqvg (III) mvj‡dU `ae‡Y 0.120 A ̈vw¤úqvi we`y ̈r KZ mgq hver cÖevwnZ Ki‡j K ̈v‡_v‡W 1.00 g †μvwgqvg mwÂZ n‡e? [DU 11-12] 12 hr 53 min 15 hr 50 min 9 hr 53 min 13 hr 52 min DËi: 12 hr 53 min e ̈vL ̈v: W = MIt eF  t = WeF MI Cr2(SO4)3 `ae‡Y, Cr Gi cvigvYweK fi, M = 52 Zzj ̈ msL ̈v, e = 3 = 1 × 3 × 96500 52 × 0.12 = 46394.23 s  12 hr 53 min 21. †jvnv‡K gwiPvi nvZ †_‡K iÿvi Rb ̈ †Kvb avZzi cÖ‡jc †`Iqv nq? [DU 10-11] Zn Pb Hg Ti DËi: Zn e ̈vL ̈v: Zn avZz Fe n‡Z †ewk mwμq e‡j †jvnvi Dci Zn Gi cÖ‡jc †`qv nq| Zn, H2O Gi mv‡_ wewμqv K‡i GKwU Av ̄ÍiY •Zwi K‡i †d‡j ZvB H2O Avi Fe Gi mv‡_ wewμqv Ki‡Z cv‡i bv| 22. Zyu‡Zi `ae‡Y 1.0 NÈv a‡i 8.0 ampere we`y ̈r cÖevwnZ Ki‡j ZworØv‡i Kx cwigvY Cu Rgv co‡e? [DU 10-11] 8.745 g 9.475 g 10.475 g 11.475 g DËi: 9.475 g e ̈vL ̈v: W = MIt eF = 63.5  8  60  60 2  = 9.475 g 23. Kcvi A ̈v‡bvW e ̈envi K‡i Kcvi mvj‡dU Gi Rjxq `aeY‡K Zwor we‡kølY Kiv n‡j A ̈v‡bv‡W †h wewμqv N‡UÑ [DU 09-10] Cu2+(aq) + 2e–  Cu(s) Cu(s)Cu2+(aq) + 2e– 1 2 H2(g)  H + (aq) + e– 4OH– (aq)  2H2O(l) + O2(g) + 4e– DËi: 4OH– (aq)  2H2O(l) + O2(g) + 4e– e ̈vL ̈v: CuSO4 Gi Rjxq `aeY: CuSO4(aq) ⇌ Cu2+(aq) + SO2– 4 (aq) H2O(l) ⇌ H + (aq) + OH– (aq) `ae‡Y K ̈vUvqb Cu2+ I H + Ges A ̈vbvqb SO2– 4 I OH– Dcw ̄’Z _vK‡jI mwμqZv wmwi‡R †h AvqbwU wb‡P †mwU Av‡M PvR©gy3 n‡e| A ̈v‡bv‡W wewμqv: 4OH– (aq)  2H2O(l) + O2(g) + 4e– K ̈v‡_v‡W wewμqv: Cu2+(aq) + 2e–  Cu(s)
4 ....................................................................................................................................  Chemistry 2nd Paper Chapter-4 24. wb¤œwjwLZ M ̈vjfvwbK †Kvl m¤ú‡K© mwVK Dw3wU wPwýZ KiÑ Zn(s)/Zn2+(aq) || Cu2+(aq)/Cu(s) [DU 08-09] The Zn electrode is the cathode Oxidation takes place at the Cu electrode The reaction Zn2+(aq) + Cu(s)  Zn(s) + Cu2+(aq) is spontaneous Electron flows from the Zn electrode to the Cu electrode DËi: Electron flows from the Zn electrode to the Cu electrode e ̈vL ̈v: GLv‡b, Zn Gi RviY wefe †ewk nIqvq GwU B‡jKUab Z ̈vM K‡i Ges Z ̈vMK...Z B‡jKUab Øviv Cu2+ Gi weRviY N‡U| A_©vr, B‡jKUab Zn B‡jK‡UavW †_‡K Cu B‡jK‡Uav‡W cÖevwnZ n‡e| A ̈v‡bv‡W wewμqv: Zn – 2e–  Zn2+ (RviY) K ̈v‡_v‡W wewμqv: Cu2+ + 2e–  Cu (weRviY) mgMÖ †Kvl wewμqv: Zn + Cu2+  Zn2+ + Cu 25. mvaviY Ae ̄’vq GKwU †fvëvwqK •e`y ̈wZK †m‡ji emf n‡eÑ [Cu2+(aq)/Cu(s) (0.05 M) = 0.34V; Zn2+(aq)/Zn(s) (0.1 M) = – 0.76 V] [DU 07-08] 1.10 V 1.80 V 0.42 V 0.62 V DËi: 1.10 V e ̈vL ̈v: Ecell = E0 cell – 2.303RT eF log Drcv` Avq‡bi NbgvÎv wewμqK Avq‡bi NbgvÎv = (E 0 Zn/Zn2+ + E 0 Cu2+/Cu) – 0.0592 e log [Zn2+] [Cu2+] = (0.76 + 0.34) – 0.0592 2 log     0.1 0.05  1.10 V 26. wb‡¤œi †Kvb B‡jK‡UavWwUi cÖgvY weRviY c‡Ubwmqvj m‡ev©”P? [DU 06-07, 04-05] H + (aq)/H2(g), Pt Cu2+(aq)/Cu(s) Na+ (aq)/Na(s) Pt, F2(g)/F– (aq) DËi: Pt, F2(g)/F– (aq) e ̈vL ̈v: mwμqZv wmwi‡Ri hZB Dci †_‡K wb‡Pi w`‡K hvIqv hvq, cÖgvY weRviY wef‡ei gvb ZZ evo‡Z _v‡K| mwμqZvi μg: Na > H > Cu > F ZvB, F2/F– B‡jK‡UavWwUi cÖgvY weRviY c‡Ubwmqvj m‡ev©”P| 27. RviY-weRviY Aa©‡KvlÑ [DU 05-06; IU 18-19] Pt, Cl2/Cl – AgCl(s)/Cl Na.Hg/Na+ Pt, Fe2+/Fe3+ DËi: Pt, Fe2+/Fe3+ e ̈vL ̈v: Ae ̄’všÍi avZzi `ywU wfbœ RviY Ae ̄’vi Avq‡bi `ae‡Yi g‡a ̈ GKwU wbw®Œq avZzi (Pt ev Au) cvZ ev Zvi Wzwe‡q RviY weRviY Aa©‡Kvl MVb Kiv nq| †hgb: Pt, Fe2+/Fe3+ Ges Au, Sn2+/Sn4+ 28. wb‡Pi †Kvb A·vBW‡K nvB‡Wav‡Rb M ̈vm Øviv weRvwiZ Kiv hv‡e? [DU 04-05] Al2O3 MgO CuO Na2O DËi: CuO e ̈vL ̈v: mwμqZv wmwi‡R H-Gi wb‡P Aew ̄’Z avZe A·vBW‡K H Øviv weRvwiZ Kiv hvq| D‡jøwLZ avZzi A·vBW ̧‡jvi g‡a ̈ ïay Cu Gi Ae ̄’vb H-Gi wb‡P| ZvB CuO †K H2 M ̈vm Øviv weRvwiZ Kiv hv‡e| 29. Zwor we‡køl‡Y †KvbwU Av‡M PvR©gy3 n‡e? [JU-D 22-23] Pt2+ Cu2+ Cd2+ Mn2+ DËi: Pt2+ e ̈vL ̈v: `ae‡Y GKvwaK Avqb GKmv‡_ _vK‡j mwμqZv wmwi‡Ri wb‡Pi AvqbwU Av‡M PvR©gy3 n‡e| cÖ‡kœv3 Avqbmg~‡ni PvR©gy3 nIqvi μg: Pt2+ > Cu2+ > Cd2+ > Mn2+ weMZ mv‡j GST-G Avmv cÖkœvejx 1. †Kv‡bv Kcvi mvj‡dU `ae‡Y cøvwUbvg ZworØv‡ii mvnv‡h ̈ 1 NÈv hveZ 1.25 A we`y ̈r Pvjbv Ki‡j K ̈v‡_v‡W KZ ̧‡jv Kcvi cigvYy Rgv co‡e? [GST 23-24] 14.04 × 1021 1.404 × 1021 14.04 × 1022 1.404 × 1020 DËi: 14.04 × 1021 e ̈vL ̈v: cigvYy msL ̈v, N = nNA = It eF × NA It = neF  n = It eF = 1.25 × 60 × 60 2 × 96500 × 6.023 × 1023 = 14.04 × 1021 wU 2. 25C ZvcgvÎvq cÖ`Ë †KvlwUi †Kvl wefe KZ n‡e? Ni(s)/Ni2+(0.1 M) || Ag+ (0.1 M)/Ag(s) hLb, E 0 Ni2+/Ni = – 0.25 V; E 0 Ag+ /Ag = + 0.80 V [GST 23-24] 0.712 V 1.050 V 1.062 V 0.80 V DËi: 1.050 V e ̈vL ̈v: Ecell = E0 cell – 0.0592 e log [Ni2+] [Ag+ ] 2 = (0.25 + 0.80) – 0.0592 2 log      0.1  (0.1) 2 = 1.02 V  1.050 V GLv‡b, mwVK Dˇii me‡P‡q KvQvKvwQ DËi n‡jv 1.050 V 3. 1 2 †gvj Cu †K Cu2+ G RvwiZ Ki‡Z KZ d ̈viv‡W Pv‡R©i cÖ‡qvRb? [GST 22-23] 0 1 1 2 2 DËi: 1 e ̈vL ̈v: Cu – 2e–  Cu2+ 1 mol Cu  2 F  0.5 mol Cu  1 F