Which of the following statements are correct? .r,e2hh e.eqp
I.Voltaic cells convert chemical energy into electrical energy
II.Electrolytic cells convert electrical energy into chemical energy
III.Electrolytic cells require a salt bridge

  Which of the following are the standard conditions for stshs q5e):z7g;7wjz 2l6ysv rl4 g,mfaandard cell potentials? rz)wh 6jgmq7,7;zs:5lg4 s2fevy s al
I.A temperature of 298K
II.A pressure of 100 kPa
III.Solution concentrations of $1\,mol\,dm{-3}$

  Which statement is correct 6/ir6xl;twh 7hkp:xf?

  Which row of the table is correct for a spontaneous o g y9 om7oxe753me3/muv 9kivreaction?

  Which statement about electrochevqb3xr gx y34+mical cells is not correct?

  What are the correct products of the reaction of nitric acid ancar*ansfwxes 7r *;*+ d magnesium metal? rrwsna;a*c xe+*7fs *

  Which statements about the electrolysis of molten alumin3,qyj obuw j9b.(9pys ium oxide are correct?
I. Aluminium ions gain electrons at the cathode
II. Oxide ions lose electrons at the cathode
III. The cathode is the site of reduction in this cell

  Which row, indicated in t*ij+thm tri5y4r 3+ iohe table below, contains the correct species that are produced at each electrode durinoh+ + *yr4t3rim5t jiig the electrolysis of molten zinc chloride?

  Which solution does not produce oxygen at the anode when electrolyzhc u,- eyo vx*ti:qv53ed with inert elec5hco* i:uv tx-3v,eqytrodes?

  Oxygen and water are producbfd9)q0u ecy,ud *9hq ed when nitric acid reacts with potassium manganate(VII), bh),q 9ucy ufqde9d0*$KMnO_4$.
$4KMnO_4(aq) + 12HNO_3(aq) \rightarrow 6H_2O(I) + 5O_2(g) + 4KNO_3(aq) + 4Mn(NO_3)_2(aq)$
1.Define reduction in terms of electron transfer.
2.State the oxidation state of manganese in $KMnO_4$ and in $Mn(NO_3)_2$.In $KMnO_4$:X= ----待选择----+-   , In $Mn(NO_3)_2$:X= ----待选择----+-   
3.Identify which species has been oxidized in this reaction and specify the change in oxidation state it has undergone.

  Which statements are correc 8dv*tqqn4r j6t about an electrolytic cell?
I. An external power supply is used to drive a non-spontaneous process
II.Oxidation occurs at the positive electrode in the cell
III.The cell could be used to extract a reactive metal from its molten salt

  The diagram below shows a voltaic cell. The overapa)q sbhl,( ui0ct(j 4ll reaction taking place in the cell isulqb) ji(p sct4(0,h a:
$Mg(s) + Pb^{2+}(aq) \rightarrow Pb(s) + Mg^{2+}(aq)$


Which statement is correct for the magnesium half cell?

  What is the balanced c ;us7rvd,rsy3 hemical equation and $E^{\theta}$ cell for the spontaneous reaction between the following half-cells?
$Pb^{2+}(aq) + 2e^- \rightarrow Pb(s)$ -0.13V
$Cu^{2+}(aq) + 2e^- \rightarrow Cu(s)$ +0.34V

  Which statement about electroplating an object with silv1 j1rrwjh3n7l er is incorrect?

  What happens to the esye 00ubqc3xc- .ffg7 6vx p:$Mn^{3+}_{(aq)}$ ion when it is converted to $MnO_{4(aq)}^-$

  A primary alcohol is heated under reflux with an aqueous so/w );5bqspc9dotics1l 6;jd alution of the oxidizing dcb a;1p/j5l6 sqotsi) cdw9;agent $KMnO_4$Which of the following is a possible product of this reaction?

  Using the voltaic cell notation given below and the standard electrode potentiavz0fp-7 iu)b-sq5 +(cwe jliq,e*ic hls, fsui)5cq-ql e- +(i ,* wecji7hv0pbzdetermine the standard cell potential of the cell,$E^{\Theta}$.
$Pb(s) | Pb^{2+}(aq) || Ag^+(aq) | Ag(s)$
$Ag^+(aq) + e^- \rightarrow Ag(s)$ +0.80V
$Pb^{2+}(aq) 2e^- \rightarrow Pb(s)$ -0.13V

  Using the following half reactions, how many molpf.- ze ft,k ;f4ucanz)0k* kkes of electrons are transferred in the equation for the oxidation of ethan-,kakfpkzz ct)0fnf *ue4k;.ol in the presence of acidified potassium dichromate when balanced with whole numbers?
$Cr_2O_7^{2-}(aq) + 14H^+(aq) +6e^- \rightarrow 2Cr^{3+}(aq) + 7H_2O(I)$
$CH_3CH_2OH(aq) + H_2O(I) \rightarrow CH_3COOH(aq) + 4H^+(aq) + 4e^-$

  Electrolysis of $Cu^{2+}$ using a current of 1A for 10s produces x mol of Cu metal.
If Q= It, how many moles of Cu metal is produced if $Cu^+$ is electrolyzed under the same conditions?

1.Draw an electrolytic cell for the electrolysivh9hf3cs) u ;lt0,2: v w9kumjjl0otrs of molten sodium chloride. Label the direction of electron t u3lc)02v vtsumrf 90jl,h 9:hj; okwflow and the polarity of the electrodes.
2. 1.Deduce the major products if dilute aqueous sodium chloride was electrolysed instead.
2.Deduce the major products if concentrated aqueous sodium chloride was electrolysed instead.

  Which of the below reactions shows the oxidation of xp o95wj .a 2,utp1 iw91ldbk5cygt8ea secondary alcohol?

  The diagram below sho7wz cnxgoiagjhe;g 0o c4-4.7 ws a Daniel cell. Zinc is more reactive than copper. When the cell is operating, which stati n7;zgch47g-e co4oax.0wj gement about the ions in the cell is correct?

  What is the reducing agen4a4mtb 6j gp;/rz g bf +s1os,iwkn,4it in this reaction?
$Zn_{(s)} + 2NO_{3(aq)}^-$ + 4H^+_{(aq)} \rightarrow Zn^{2+}_{(aq)} + 2NO_{2(g)} + 2H_2O_{(I)}$

  The below diagram shows an elect k0h11q 9v0n e2zvulb,hd8mu grolytic cell. At which electrode will bromine form, and whatvdb0u2n 8g ezq91mhhluv ,k01 is the process taking place there?

  The diagram below shows a Daniel cell. Zinc is more reactive than copper. Whe3 n7/is 0k xrn + e8lvdrh1s8thcwae(,n the spontaneous reaction occurs, which statement about the D,8 ci lr+deare(h nk38t wh1s0 sxn/7vaniel cell is correct?

  The equation for the ovec+pnrl2-6dbk x ;;yihrall reaction in a voltaic cell is:
$Cu(s) + 2Ag^+(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)$
Which statements are correct for this cell?
I. Electrons flow from the copper electrode to the silver electrode
II. Silver ions are reduced in the reaction
III. The copper anode will become smaller in size as the reaction proceeds

  What are the respective oxidation states of sulfur in the following su6kryu: mvt 254/n6zkq(s dhml :aav7 glfur-containing specvnkm l:ts6v:g(a5 dmz/a 2r476ykhquies?
$SO_3^{2-}, H_2SO_4, S_8, S_2O_3^{2-}$

  Alkali metals react 5-e(cw2 odrqnwith water to form metal hydroxide and hydrogen gas.
1.Write a balanced equation between sodium and water.
2.Explain why this reaction is considered as a redox reaction.
3.3 other alkali metals W, X and Y also react with water.
Based on the following observations, arrange the metals in order, starting from the weakest oxidizing agent. Explain your answer. ----待选择----XYW $\lt$ ----待选择----XYW $\lt$ ----待选择----XYW $\lt$

Meta	Observations
W	Slow reaction with water
X	Vigorous reaction with water
Y	Fast reaction with water

  What happens to nitrogen when nitrate changes to p4 4wycckz6yn v+px 68atsg72nitrite ?

Sodium metal may be obtained commercially from the electro8s u.uk5b fj9knx:4q olysis of molten sodium chloride in a Downs cell. This cell operates as an electruj o s5u: kxk.f8qbn94olytic cell.
1.Describe, using a diagram, the essential components of this electrolytic cell.
2.Suggest why molten sodium metal may be collected from the top of this type of cell.
3.Describe two ways in which current is conducted in an electrolytic cell.

  A battery is added to a container of molttz r.xg7eoa6 2/ xb.80c6tx 6tiukwqjen $CaBr_{2(l)}$ to create an electrolytic cell, as shown in the diagram below.



1. 1Use section 24 (Section 19- 2025 Syllabus) of your data booklet to identify and write the oxidation and reduction half-reactions.
2.Label the anode and cathode on the diagram above.
3.On the diagram above, label the electrode where calcium metal $(Ca_{(s)})$will appear.
2.A different electrochemical cell is shown below. One half-cell contains a lead metal electrode immersed in 1.0 M $Pb(NO3)_2$ solution. A standard electrode potential table is also shown for elements X, Y, and Z.

Elements	Electrode potential
$X^{2+}_{(aq)} + 2e^- \rightarrow X_{(s)}$	$E^{\Theta}$=-1.18V
$Y^+_{(aq)} + 1e^- \rightarrow Y_{(s)}$	$E^{\Theta}$=-0.45V
$Z^{2+}_{(aq)} + 2e^- \rightarrow Z_{(s)}$	$E^{\Theta}$=+0.34V

1.Label the left half-cell of the diagram with the metal that will produce the highest cell potential.
2.Draw an arrow on the diagram indicating the direction of the flow of electrons.
3.Consult section 24 (Section 19- 2025 Syllabus) in your data booklet to calculate the standard cell potential for the diagrammed cell.  V
4.Use metals X, Y, and Z combined with aqueous chloride solutions of metals X, Y, and Z, and write a balanced equation for a reaction that will proceed spontaneously.

  Consider the followinf.qyp9nm+m :c(eys l9g redox reaction:
$Cr_2O_7^{2-}(aq) + 14H^+(aq) + 6Ag(s) \rightarrow 2Cr^{3+}(aq) + 7H_2O(l) + 6Ag^+(aq)$
1. 1.Using section 24 (Section 19- 2025 Syllabus) of the data booklet, calculate the standard cell potential.  V
2.Predict, with a reason, whether this reaction is spontaneous or not.
2.Using sections 1 and 2 of the data booklet, calculate the standard Gibbs free energy change in $kJ\,mol^{-1}$.
The standard entropy change for this reaction is $508J\,K^{-1}\,mol^{-1}$
3.Using section 1 of the data booklet, calculate the standard enthalpy change for this reaction in $kJ\,mol^{-1}$.
$\Delta G^{\Theta}$=  $kJ\,mol^{-1}$, $\Delta H^{\Theta}$=  $kJ\,mol^{-1}$

  The Daniell Cell is a galvanic ce r xr oe;)9avh0/zqt1all with a standard cell potential of 1.10V.
$Cu^{2+}(aq) + Zn(s) \rightarrow Cu(s) + Zn^{2+}(aq)$
1. 1.Define standard electrode potential.
2.List the features of a standard hydrogen electrode (SHE).
Suppose the SHE is replaced by a MMSE reference electrode with a standard electrode potential of 0.64V.
2. 1.Using section 24 (Section 19- 2025 Syllabus) of the data booklet, calculate the new electrode potentials.Cu(s):  V, Zn(s):  V
2.Using your answers to (b)(i), calculate the new cell potential and comment on this value.$E_{cell}$=  V

For each reaction des/psiz3t 0gtuxcguo0 h n*q;+ 4cribed below, specify its type and write its complete balanced chemical equation using the structural formulas of reactants and prnqp sg0it 0cozu x*4/uh+ tg3;oducts.
1.Formation of butane from but-2-ene.
2.Formation of but-2-one from butan-2-ol.

  Titration technique yi4qcie8(aur e r3:6i yqq+, kcan be used to determine the percentage of copper present in a sa8eeiy6:ir(a rquq, c i3yqk4 +mple of copper (I) oxide. The sample is first dissolved in acidic solution and $Cu^+$ ions are formed. The resulting solution is then titrated against a standard solution of potassium manganate (VII),$KMnO_{4}$. In acidic solution,$MnO^-_4$ reacts with $Cu^+$ to form $Mn^{2+}$ and $Cu^{2+}$ ions.

Titre	1	2	3
Initial burette reading/$cm^3$	2.00	24.70	5.00
Final burette reading/$cm^3$	25.80	48.30	30.60

Mass of copper oxide (I) sample/g 0.7751
Concentration of $KMnO_{4}$ solution/$mol\,dm^{-3}$ $2.375\times10^{-2}$
1.Using Section 24 (Section 19- 2025 Syllabus)of the Data Booklet, write the equation of the redox reaction.
2.Define reducing agent and specify the reducing agent in the reaction.
3.Calculate the number of moles of $MnO^-_4$ that reacted with $Cu^+$.  $cm^3$
4.Deduce the percentage by mass of Cu present in the sample.  %
Important note: The section numbers mentioned in the video solution are specific to the 2024 syllabus.
You can refer to the question stem to find the section numbers in the 2025 syllabus.

  Consider the following reactions involving metals and their aqueous nz gk (av2x.*st wr50ztitrate solutions: xa2rvzkst5 *wg(z 0.t

	$XNO_3$	$Y(NO_3)_2$	$Z(NO_3)_2$
Metal X		No reaction	No reaction
Metal Y	Grey solid of metal X observed		No reaction
Metal Z	Grey solid of metal X observed	Pink solid of metal Y observed

Choose the correct order of the metals from the strongest oxidizing agent to the weakest?

  Consider the following rf c0eky*6ug wudg17 fkr *gs53eactions:
$Fe(s) + Cu^{2+}(aq) \rightarrow Fe^{2+}(aq) + Cu(s)$
$Fe(s) + 2Ag^+(aq) \rightarrow Fe^{2+}(aq) + 2Ag(s)$
$Zn(s) + Fe^{2+}(aq) \rightarrow Zn^{2+}(aq) + Fe(s)$
$Cu(s) + 2Ag^+(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)$

  The equation below shows the reactioo/axdymg ;z 2mjvwqr( 3+3ja:fat p 15n between concentrated sulfuric acid and potassiummj5y+2xp3o /;1 3vatwmqar dgaf z (j: iodide.
$8KI(s) + 5H_2SO_4(aq) \rightarrow 4K_2SO_4(aq) + 4l2(g) + H_2S(g) + 4H_2O(l)$
1.State the oxidation state of sulfur in $H_2SO_4$ and $4H_2S$.In $H_2SO_4$, x= ----待选择----+-   , in $4H_2S$, x= ----待选择----+-   
2.Write the half equations for the oxidation and reduction reactions.
3.Define oxidizing agent in terms of electrons.
4.Identify the oxidizing agent in the equation.

  Consider the following s :e)qtixjrejv2b)iai8-o 4/ equations:
Equation 1:
$2ClO_3^-(aq) + I_2(aq) \rightarrow Cl_2(aq) + 2IO_3^-(aq)$
Equation 2:
$ Cl_2(aq) + 2NaOH(aq) \rightarrow NaCl(aq) + NaClO(aq) + H_2O(l)$
Which statements about these reactions is/are not correct?
I.Iodine is reduced in equation 1
II.Chlorine is reduced only in equation 1
III.Chlorine is oxidized and reduced in equation 2