Bài tập và lời giải về điện hóa học trong chương trình AP bao gồm các chủ đề quan trọng như pin điện và quá trình điện phân. Những bài tập này không chỉ giúp học sinh hiểu sâu hơn về các khái niệm cơ bản mà còn cung cấp cơ hội để áp dụng kiến thức vào các tình huống thực tế. Đặc biệt, việc giải các bài tập liên quan đến pin điện giúp học sinh nắm vững cách tính toán năng lượng sinh ra từ các phản ứng hóa học, trong khi các bài tập về điện phân giúp hiểu rõ hơn về quá trình chuyển đổi điện năng thành hóa năng và ngược lại. Tất cả những bài tập này đều được thiết kế theo chuẩn của chương trình AP, nhằm giúp học sinh chuẩn bị tốt nhất cho kỳ thi cuối khóa.
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Date Ch.17 — Electrochemistry: Practice Problems I
a) +2.97V Reduction Potential, Z°
4 For the reaction shown below, E°cey = 0.79 V
` 6T (dạ) + Cr207 (ag) + 14H* > 3h; (aq) + 2Cr** (aq) + 7HOfaq)
Given that the standard reduction potential for Cr077 = 2Cr** is 1.33 V, whatis E Re
CQ Œ2 ¿ for la(aq)?
“16 V} M(s) +3 Ag'(aq) > 3 Ag(s) + MỸ (4) E Pil
b) -0.06 V Ag'(aq) + & > Ag(s) E=+0.80 V
Trang 26)
8)
3)
Use these reduction potentials to determine which one of the
reactions below i is ‘Spontaneous —> Ex œ = =
Se Vv +2Ag> 2A E: ~~ P)— (PEOALO coe ? 2) Reaction Potential B° =—
@axtd os ete = (z/3)~( | Agf+e >Ag | 0.800V ¿
a) Cụ + Cđ?! > Cu” + Cả net Cathole
b) Cu + Cả > Cu?" + Cá?” (0xìdslflerÀ (reolxeftern)
Calculate E° 7 and AG® for the reaction 2Br (ag) + F2(g) > Bro) + 2F (aq)
Given the following reduction potentials: Bro) + 2& — 2Br (aq) E° = 1.06v [0x dati)
Is the reaction spontaneous? , F2(g) + 2e- > 2F (aq) E° = 2.87V { Ce eoleol ion
Evel = (2.99) - (108) =F) PIV 2 Elle 70 ea hers -770- F- Eee 3 $345 DPE
7647S EX) | tài A= 47 S= —_ (2 we) (5 A) {+
KG? =" 347 F>
al
Trang 3candle — ỐC 2x kD
10) Calculate E°„„ and AG°? for the following reaction: Cd| Cd** lI Cu?” | Cu
Is this reaction spontaneous? eicledie
éd —» C2heze Ered = OH07 per (ere e)/ 700 we) 10743 Kral &
Trang 414) Solutions of Ag”, Cu", Fe** and Ti* are electrolyzed with a constant current until 0.10 mol of metal is deposited Which will require the eats length of time? Ti 4 +
15) How many grams of cobalt metal will be deposited when a solution of cobalt (IJ) chloride is i
electrolyzed with a current of 10 amperes for 109 minutes? =
16) How many minutes will it take to plate out 4.56 g of Ni metal from a solution of Ni” using a
current of 45.5 amps in an electrolytic cell?
Trang 5Free Response Question 2006 # 2
a The standard reduction potential for two half-reactions at 25°C and 1M concentration are given on the table below
i Write the balanced net-ionic equation for the overall reaction ii.’ Which of the metal ions is reduced in the reaction? Which metal is oxidized? iti Calculate the standard potential, E°, and the free-energy, AG®, for the overall reaction at 25°C
() Caflicle/ Recbac tion 2 Co 4 2e Co 6%-02®Vv
amsde/0xiosjen vn ~Y z†?+ se -£““-(2T©V
Cotte Blot Ze’ Etees eae Vv (est) ——~
=e
Gs ot 1s reclaced › #2 5 uxich zed
it) AGP FE cace APs —(2rnte) (16A8SE (CHES)
KG? = ?2/2€ Tu A 22 kXe«a
b Hydrogen peroxide, #2Ó;, decomposes according to the following equation:
(CÀ ?H;Oz(aq) 2 2I›O() + Os(g) E°=0.55V
The half-reaction below is shown with its standard reduction potential:
(B) Oz@) + 4Hf(aq) + 4 2 2H:O() E°=1.23 V
Using the information above in addition to the equation for the decomposition of H202, determine the value of the standard reduction potential, E°, for the half-reaction below
O2(g) + 2H (aq) + 2e° > HO2(aq)
Trang 6Free Response Question 2001 # 7
Answer the following questions that refer to the galvanic cell shown in the diagram The two reduction half-reactions that
occurs in the cell are shown below
value of the standard cell potential, sp
c Determine the value of the standard free-energy, AG° cen, for the cell d Indicate how the value of E27 would be affected if the concentration of Ni(NO3)2(aq) was changed
from 1.0M to 0.10M and the concentration of Zn(NO3)2(aq) remained at 1.0M Justify your answer
Ab eet = - JO2 274 Soule wy - AOX12
[ans Conte QUOD
Trang 7
Free Response Question 2003B # 6 '
a Different electrochemical cells can be constructed using the solutions and electrodes shown below
The standard reduction potential for the chemical species are
given on the table
Chose the most suitable pair of half-cells and write the balanced
net-ionic equation for the spontaneous reaction that occurs in the
cell that would have the greatest positive value of F° 7 rs — Cathode /deduetion : GE* + 22 xác G3 EO
Arvicbe] Oxidhatyonr: ip > Aer Be (x2) Pee ore | 0.44 nT OS
c A cell is constructed based on the reaction defined in question (a)
i Label the correct metal strips used for the anode and cathode
electrodes on the cell shown in the diagram below
Anode: Ale YONI TA Cathode: ce 22c“
ii On the diagram above, show the direction of electron flow between the electrodes of the cell
-d Another galvanic electrochemical cell is based on the following reaction: Zn+ Pb** > Zn’* + Pb
i Ifthe concentration of Zn’* is decreased from 1.0M to 0.25M, what effect does this have on the cell oncentranon OF on 1s decrease?
potential? Would eeu increase or decrease? Justify your answer
Ececte uel inerease fecal hy LeChafelcer's 2 seynk,
ZŠø722222, fe none tate of He <6 (Zn? 9 ae
He “eacen 1⁄22 te z2 ) 2/2281 tte few ee
electrns ard Pnevecan tt Cell poTerdiat Eire QE +
ii [fthe concentration of Pb” is decreased from 1.844 to 0.25M, what effect does this have on the cell potential? Would E,.y increase or decrease? Justify your answer
Lover youtd oeorase ecdy, to Jechote her's Pircipl, Z
fecteantn 79 He concern re œ2 the reactarhts (pL?) drives
re eacthior J5 He Ke coc fou, receeoy the pw
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and reclucéG Ecrtl.
Trang 8Free Response Question 2002 #2 The reaction between silver ions and solid zine is S given by the following
equation:
2 Ag” (aq) + Zn(s) > Zn?" (aq) + 2 Ag(s)
a A 1.50g sample of Zn is immersed in 250 mL of 0.110M AgNO3
i Identify the limiting reactant Show work to support your answer
ii On the basis of the limiting reactant that you identified in part (i), determine the value of [Zn7"] after the reaction is complete Assume that volume change is negligible
b Determine the value of the standard potential, E° 7, and the standard free-energy, AG cen, for a galvanic
cell based on the reaction between AgNO3(aq) and solid Zn at 25°C
(Zz.t) xX mol Ag* - (50g Øn[ ý>Zr)› DONS? root by”
needled E278) | ena € Be neecked for ren
(eid) vat #n” *— 0.02 7X mỄ &eT Lost BP ‘\ 0.0132 mol Bn?”
6 tached ` e¿ Che 2 a£ Ast reacted
DG 2/2 ~Pì E5 De ate — [aml 2| BE) 1,5G\
Trang 9c Another galvanic cell is based on the reaction between Ag” (aq) and Cu(s)
i, Write the balanced net-ionic equation for the reaction that occurs in
the galvanic cell
ii Determine the standard potential, E°, for the cell at 25°C
thw & a
(- iv) “s4 wort decrease Hoods to lech afeliers mee
(meres 7q He Comeentrafion IF ~ prockuct (% 5
dee the rooster fouards He reactors, ft e<
the plows of! ehclons endl reduviong He cet€
potertin€ ( œ4).
Trang 10solution at 25°C As the cell runs, copper metal is deposited onto one
electrode and O2(g) is produced at the other electrode The two
reduction half-reactions that occur in the cell are shown below
OÓ;() + 4 H*(ag) + 4£ © 2H;O () +1.23 amy Ko
Cu?" (aq) + 26 > Cu (s) +0.34 Cu (a4) +2#7—— Cuts)
a On the diagram above, indicate which electrode is the cathode, which is the anode and the direction of electron flow between the electrodes :
b Write a balanced net ionic equation for the overall electrolysis reaction that occurs in the cell
c Determine the value of cell reduction potential E” and the free energy AG® for the reaction d What is the minimum voltage that must be applied across the electrodes to drive the reaction? e An electric current of 1.50 amps passes through the cell for 40.0 minutes
i Calculate the mass, in grams, of the Cu(s) that is deposited on the electrode ii Calculate the dry volume, in liters measured at 25°C and 1.16 atm, of O2 (g) that is produced
() Cattoclel Peduction ' » +2e —y 4 | (24
xe Joni: joni = ZH,O —7 0, + HHT + te