Which of the following statements are correct?o;t b4v hq*bc;
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 consyp 3hx-;/zsa*pf3 xn2inmmxbe t03 *ditions for standard cell potentials?*inzh3ys*x e3t0/p -2 bxsmaxpmn; 3f
I.A temperature of 298K
II.A pressure of 100 kPa
III.Solution concentrations of $1\,mol\,dm{-3}$

  Which statement is correct? l6 6s 5k7ays s6csi1xwootv*0tns7+j

  Which row of the table is correct for a spontaneous q l*)hv:4y-c xioe9kr28 fimireaction?

  Which statement about electrochemical cebb6 w9l6 t3j,-f dwrwnlls is not correct?

  What are the correct products of the reaction of nitric acykbl 55 bt a8lpcngx 3x4frzd26)*q v+id and magnesium metal?3k)56n cl*x8 y2t prlg vq ax+b5bdz4f

  Which statements about the electrolysis of molten al7366)uh wgxg/fikjjonfcug 6 , .w,bcuminium 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 snnf ,0kkez 5n** h1 hx9odfx*the table below, contains the correct species that are produced at each electrode during the electroxx*heon5fkn ,kn0*zd*h 19s f lysis of molten zinc chloride?

  Which solution does not produce oxygen at the anode fn,ivn.8 f 1*zk,i; vdw k.qlvwhen electrolyzed with inert electrodes?;vzl wk.kfq,f, nvidin .v18 *

  Oxygen and water are produced w3l +dyf*9f0c y*kfdj ti/dzl8x43fhk ,anz. when nitric acid reacts with potassium manganate(Vi9,wzxyf d tlfkyf8d n3f/ 0a dh4+.j cz**k3lII),$KMnO_4$.
$4KMnO_4(aq) + 12HNO_3(aq) \rightarrow 6H_2O(I) + 5O_2(g) + 4KNO_3(aq) + 4Mn(NO_3)_2(aq)$
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 c29 a8jfh* mcr/bahl 2norrect 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 overal2zx --z+ybeo cl reaction taking place in the celby-z-+e ox2czl is:
$Mg(s) + Pb^{2+}(aq) \rightarrow Pb(s) + Mg^{2+}(aq)$


Which statement is correct for the magnesium half cell?

  What is the balanced chemicalb. cgyt*/ug 5pvlk,yt.+q :fc 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 a+/e e2llh5dpf n object with silver is incorrect?

  What happens to the ,ncgbmg2wc ( :+d6esa $Mn^{3+}_{(aq)}$ ion when it is converted to $MnO_{4(aq)}^-$

  A primary alcohol is heated under reflux with an aqueous solution of p md::h;p (l,bgaaj,u xfi1(l the oxidizing agent a,xp; bhp a,dm f(:l( :giuj1l$KMnO_4$Which of the following is a possible product of this reaction?

  Using the voltaic cell notation given below and the standard electrode pod)wy48jkb n n*vw0 pk-kw5f:rtentials, determine the standard cell potential of the0fr4wwj k vp:nnd-ky5)* w bk8 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 reactionsmk(p7v3 2r k*nk v)rlt, how many moles of electrons are transferred in the equation for the oln*rpkmk(2)37 v r tvkxidation of ethanol 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 electrolysis of molten s.ci2g .;po1dte c7fgzodium chloride. Label the direction of electron flow and the polarity of the electrodectgf1 z.7 2pcdeig. ;os.
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 a secondars7 :idr 8 ,4,f.wtclvgbyol d6y alcohol?

  The diagram below shows a Daniel cell. Zinc is more reactive than coppvmw:*( uo8) 99ya7d wclk5rrw0dkz fner. When the cel( v9 kkfnw0w9lzm8wd a*)c:ry7u 5rdol is operating, which statement about the ions in the cell is correct?

  What is the reducing agent in this req fyw:dtiw* 4r,s9lc/action?
$Zn_{(s)} + 2NO_{3(aq)}^-$ + 4H^+_{(aq)} \rightarrow Zn^{2+}_{(aq)} + 2NO_{2(g)} + 2H_2O_{(I)}$

  The below diagram shows an electrolytic cell. (/p3 w8eu-qo5i .mp ptibb,i7 ytdo p/At which electrode will bromine form, and what is the ptto p/(pdow,8ye 3/p- b7u5qmi pbi.irocess taking place there?

  The diagram below shows a Daniel cell. Zinn;o ya /(lur t-yck29e.t:al,jhflg + c is more reactive than copper. When the spontaneous reaction occurs, which statement about the Daniel cell is ljtl cyko2 y+hgf-9:(a /u,;tle.narcorrect?

  The equation for the overall reaction in a voltais)yjq r 5f,-.8.ih z*uabnsd cc 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 iiy wr +w2tz xhv(en082xdb y98u 7v;nxgmmx;8n the following sulfur-containing speciex;d mymt+wgyn 7eb x9(2z uxx2w nir88v08vh; s?
$SO_3^{2-}, H_2SO_4, S_8, S_2O_3^{2-}$

  Alkali metals react with water to form metzthu6te5 ;(n; v3 ywqmal 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 nitrogdz ntnm35**mub u4 ph3en when nitrate changes to nitrite ?

Sodium metal may be obtained commercially from the electrolysis0s 5kcmt5 2lud of molten sodium chlcl0u s2tm 5k5doride in a Downs cell. This cell operates as an electrolytic 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 m-0fbw;u1rfel q. wm-holten $CaBr_{2(l)}$ 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 following redoxj, zwx4sgr6.d 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 cell with a standard cell potential ofnxnja)-q:x* s o9 ea5t 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 described below, specify 0l)wsl9f e(,5i itvdy its type and write its complete balanced chemical equation using the structural f,ftevd w9 5(i li0)yslormulas of reactants and products.
1.Formation of butane from but-2-ene.
2.Formation of but-2-one from butan-2-ol.

  Titration technique can be used to determine the percentage of copper pres 5wcabr,1z-xl ent in a sample of copper (I) oxide. The sample is firsr51,xcwa bz-lt 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/ t3m n(htr3pyluq8y+ s)cca+ nitrate solu+t/mcu qt ryhna+l)8sy 3c( p3tions:

	$XNO_3$	$Y(NO_3)_2$	$Z(NO_3)_2$
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 reactu ewv i-u5hna,xfm0tek7/ )q7k4me (b ions:
$Fe(s) + Cu^{2+}(aq) \rightarrow Fe^{2+}(aq) + Cu(s)$
$Fe(s) + 2Ag^+(aq) \rightarrow Fe^{2+}(aq) + 2Ag(s)$
$Zn(s) + Fe^{2+}(aq) \rightarrow Zn^{2+}(aq) + Fe(s)$
$Cu(s) + 2Ag^+(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)$

  The equation below shows the reaction between concene( hs(ealn dh+9gj86ll9,is6e y jx4 bv).xc btrated sulfuric acid and potassi 9ca +ljxvssjx8yeb(e.)b, n lde 9 6hhlgi46(um 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 equa1xvj e)2g ;g :td*omaktions:
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