Which of the following 5:n8sy b,q)3c bynaub statements are correct?
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 t t;i 5f+uyjz/ ;g(qvbthe standard conditions for standard cell potentials?vt/;i f+5u z(jtbgy ;q
I.A temperature of 298K
II.A pressure of 100 kPa
III.Solution concentrations of $1\,mol\,dm{-3}$

  Which statement is corre twihgqs e-po3-sr1- 4ct?

  Which row of the table is correct for a spontane7g,aw*s5qqx*c n s,tgous reaction?

  Which statement aboutq rod2hlqx:, 79s1vyh electrochemical cells is not correct?

  What are the correct products of the reaction of nitric acid and m;be-1wmn e0a q7+pvl xagnesium metal?1a 0 e+x;nw-p7qlv ebm

  Which statements about the electrolysis of molten aluminium oxide are coabxgw)fm* 2z.4nbp*k+h qei(a 9) we irrect?
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 i:nd j f1suv61/nyf kykx9d3e *n the table below, contains the correct species that are produced at each electrode during the electrolysisx nvs1 nke/1ydf u3j9fyk6d *: of molten zinc chloride?

  Which solution does not produce oxygen at the anode when electrolyzed with inernvd*cf vt c648k tc19yt electrodes?9cv*ctcfv 4 168kndy t

  Oxygen and water are produced when nitric acid reacts with potassi6lgg+ yjx:o bev u/*,ium manganate(VII)*leig/ u :g bovxj,+6y,$KMnO_4$.
$4KMnO_4(aq) + 12HNO_3(aq) \rightarrow 6H_2O(I) + 5O_2(g) + 4KNO_3(aq) + 4Mn(NO_3)_2(aq)$
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 correct about an egp2(sn4l c g+4tlf)xu arp)p(+sge)xlectrolytic 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 overall reaction taking la -5js:n;v+ twf5/ r,tvlzwz place in the cfzl /+wn v55t ,jsz-;vrltw a:ell 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 chemical equation andc )6nc/3 qgvsoorgq -8 $E^{\theta}$ 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 electroplkr2n 2uqbih47ating an object with silver is incorrect?

  What happens to the ut zu6q3+ 2mtm$Mn^{3+}_{(aq)}$ ion when it is converted to $MnO_{4(aq)}^-$

  A primary alcohol is heated under reflux with an aqueous solution of the ofxam 7fq 6*de7xidizin fde* 6mqxa7f7g agent $KMnO_4$Which of the following is a possible product of this reaction?

  Using the voltaic cell notation 3ioq0:j h)b:h o y)opagiven below and the standard electrode potentials, determine the standard celhoioay hb3 q) )::jop0l 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 -h4j7v 3brgahb*:puku; cn lw vk/ )4 u9lvl(pmany moles of electrons are transferred in the equation jvb4:7c klll 4uga(-ub3p w pv9;h nhukv/* r)for the oxidation 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 cph6/huqf77)p-imh i the electrolysis of molten sodium chloride. Label the direction of electron flow and thp6ih- /hiuc7)fqpm 7 he 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 react gz1 o 4ba,;/qjn8dk j8xa olj:tak6)qions shows the oxidation of a secondary alcohol?

  The diagram below shows a Daniel cell. w4*j 4s2 sle+ql8d yv4xrqps*Zinc is more reactive than copper. When the cell is operating, which statemjlq x rwp4q*8*l+4 syssd4v2 eent about the ions in the cell is correct?

  What is the reducing agent in this ocbtah;uh, -w*g )y jkbe8)71htn : ywreaction?
$Zn_{(s)} + 2NO_{3(aq)}^-$ + 4H^+_{(aq)} \rightarrow Zn^{2+}_{(aq)} + 2NO_{2(g)} + 2H_2O_{(I)}$

  The below diagram shows an electrolytic r9:cf +m ar-wcloutt(*a5 pd08x(vf wcell. At which electrode will bromine form, and wt:r pdtfc*or9 a 5lu(-v m8x+f0c w(wahat is the process taking place there?

  The diagram below shows a Dacw; t 3.kfnf.oniel cell. Zinc is more reactive than copper. When the spontaneous reaction occurs, which statement ft..cn;wkof 3about the Daniel cell is correct?

  The equation for the overale9g*9p6x chnf0:x f jhl 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 4 l0i2eg9sbz*2vi1 icn ;b j*amx;srh sulfur-containin z*gi*l2bsm4invb 0j9 hs1; ir;x2aceg species?
$SO_3^{2-}, H_2SO_4, S_8, S_2O_3^{2-}$

  Alkali metals react with water tazf1vr2q 81 cxo 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 wh2)+s ut/t- rk4y19xk*i/pibjr oyqsf- bp9ec en nitrate changes to nitrite ?

Sodium metal may be obtained commercially fru2 -vsx.pkht 8ef2,15rh a6ra(fn5ywpez( u e om the electrolysis of molten sodium chloride in a Downs cell. This cell operates as an electrolytic ct 2ykf a6z1nv,ps5 8xrahe2-rfhe .eu(p 5u(well.
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 m t51(*-btloq*mpopu container of molten $CaBr_{2(l)}$ 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 redox rredut/ jwqag,, 50kas 1oe/xns4gm2a8jo .a6eaction:
$Cr_2O_7^{2-}(aq) + 14H^+(aq) + 6Ag(s) \rightarrow 2Cr^{3+}(aq) + 7H_2O(l) + 6Ag^+(aq)$
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 potentia*s jh)ebi ;fp7qswvrec:72i+ l 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 described below, specify its type and write its yfe9 v 5gv/ zx58pvzr1complete balanced chemical equation using the structuraf5vpy51vezr g98z/ x vl formulas 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 h,m6lp v9jvz9 3vfhlft))o4bused to determine the percentage of copper present in a sample of copper (I) oxide. The sathvjpff 3m99)ovll) b 4z, hv6mple 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 nitht/u4sjj0n6w iw) +ki rate solution4/wu )itni j0sk+j6whs:

	$XNO_3$	$Y(NO_3)_2$	$Z(NO_3)_2$
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 reactions: rt n(j sdvsi-; +i0d5b
$Fe(s) + Cu^{2+}(aq) \rightarrow Fe^{2+}(aq) + Cu(s)$
$Fe(s) + 2Ag^+(aq) \rightarrow Fe^{2+}(aq) + 2Ag(s)$
$Zn(s) + Fe^{2+}(aq) \rightarrow Zn^{2+}(aq) + Fe(s)$
$Cu(s) + 2Ag^+(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)$

  The equation below shows ;*h j 4l+/qgusnym+bm h6ww1kthe reaction between concentrated sulfuric acid and potassh4n++ l w1yhwus *6g;mqjkb/ mium 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) gjdv-ijkyoln cqy/0 ;rn0, , 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