Which of the following stateme 8lcgs.7yq e,w i)cv zuo sam15o5d( c0;xlno4nts 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 arz gpi.*ff*3 tj ov.n3be the standard conditions for standard cell potentials? 3v**of p..t3bjniz fg
I.A temperature of 298K
II.A pressure of 100 kPa
III.Solution concentrations of $1\,mol\,dm{-3}$

  Which statement is corremk7m3la g)jy- ct?

  Which row of the table is correct for a spontaneous rny1n ofcrf; *7+z(unu eaction?

  Which statement about electrochemical cells is noom 6pbu/*;uq at correct?

  What are the correct products of the reaction of nitric acid and magnesi /1;-a wz-qzkq7p xc1cy y2*sg ygunq9um metal1gpn-y91acg-cz q ywkz /*s7qyq u;2 x?

  Which statements about the electrolysis of molten aluminium oxide are correct? q8s .e5mg9it ry-neb:
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 the table below, containsuxj ++ximkvk14p31 peo*gp a ; the correct species that are produced at each electrode during the electrolysis of miavxu+4e1k ;jpkp* 3+1 xmgpoolten zinc chloride?

  Which solution does not produce oxygen at the anode when electrolyzed with inertev: i+ii3r2rqcd2;bu ur di3 2i;i:qev+rc2b electrodes?

  Oxygen and water are y.qju0/h-0 d 7a)ut hgtaqgd.produced when nitric acid reacts with potassium manganate(VII)dghju a ua.tg0t/ q0.qd)h7-y ,$KMnO_4$.
$4KMnO_4(aq) + 12HNO_3(aq) \rightarrow 6H_2O(I) + 5O_2(g) + 4KNO_3(aq) + 4Mn(NO_3)_2(aq)$
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 electrol-ftr d1gzpvn3qsec un 7 0n.13ytic 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 vc. :eqbm,9)epoyo8x y +uh e+eoltaic cell. The overall reaction taking place in the o.eq 9+m x: p8eoeu ey+c)hy,bcell 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 anl/rud ww04u 8 y.xmyx3d $E^{\theta}$ 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 aw4ozs1w grlyfwu 6, .fr*0c+xn object with silver is incorrect?

  What happens to the dn lbqho.2b d0y1ts5e,.vjh +$Mn^{3+}_{(aq)}$ ion when it is converted to $MnO_{4(aq)}^-$

  A primary alcohol is heated under reflux with an aqueous solution of f17yh1) : n5 qcn*ymfy+dv osqthe oxidiziv)7os+q ncyqf:5m* fy1d y1nhng agent $KMnO_4$Which of the following is a possible product of this reaction?

  Using the voltaic cell notation given below and the standard elec e prt s2xtpqxjv0( 3:4f,wwa ia5l8.ftrode potentials, de4p:5rt q2 (awl.3ji 8tap,xvf0xews ftermine 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 react2(*r 4(*wcyghtc cgvf1jitb,ions, how many moles of electrons are transferred in the equation for the oxidation of et*bivc(fwgyg,c(24c *j1 th rthanol 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 sodium ch1 c.*dscs+s p)-ag p8(qgih lbloride. Labe8gd(p bc)c* s hal1 +pissq.g-l the direction of electron flow 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 aqa9 0:wl0tyhpok55j)vv jn , the oxidation of a secondary alcohol?

  The diagram below shows a Daniel cell. Zinc is more reactive than coppe3xufwt*: ukmut leg5i0h0, 3k r,lt; ir. When the cell is operating, which statement about the ionsi e;l3 3wt,kt*x,u0iu 05gmlt:k ufrh in the cell is correct?

  What is the reducing w*hn mkk7-+a7rb5so mp l+ y2cagent in this reaction?
$Zn_{(s)} + 2NO_{3(aq)}^-$ + 4H^+_{(aq)} \rightarrow Zn^{2+}_{(aq)} + 2NO_{2(g)} + 2H_2O_{(I)}$

  The below diagram showm-r k,ggkvn9jcqw +7kt h3n ym .j05e/s an electrolytic cell. At which electrode will bromine form, and what t,vcj0m. jg5ekk- 9n/3 q w 7hrnyk+mgis the process taking place there?

  The diagram below shows a Daniel cell. Zinc is more reactive than copper. Whk .(jf q)*w*kyqovfh2en the spontaneousqy)hj* f kv(.*k ofwq2 reaction occurs, which statement about the Daniel cell is correct?

  The equation for the overall s-5z- qm tpnu0yc 22mfreaction 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 fol-81-fq ioorynwvmt 10 lowing sulfur-contav 8y- w10-fo1tqm niorining species?
$SO_3^{2-}, H_2SO_4, S_8, S_2O_3^{2-}$

  Alkali metals react with 7vbgkahw3u2 n.;j8e u 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 when3 ,u 6k1gzepej nitrate changes to nitrite ?

Sodium metal may be obtain5o-4 ovr :mvxjmqc8w i us74vw6py:m1ed commercially from the electrolysis of molten sodium j 4m8 q6ypx1 sorc:v:oi -mwm5u7vw4vchloride 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 t+ 21ju8a tbabgo a 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 r:/rgxbv t.ve6mrq ,j1 ,bfv2 eeaction:
$Cr_2O_7^{2-}(aq) + 14H^+(aq) + 6Ag(s) \rightarrow 2Cr^{3+}(aq) + 7H_2O(l) + 6Ag^+(aq)$
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 a.jg23z.cz dln3 qph9cell 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 described below, specify its type and write its complete ba+ f5o*kf,ci,epu max3lanced chemical equation using the structural formula*akci, 5ump+oex, 3ffs 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 present inr:3sl0xymhp .nyp zw hf/.;s, a sample mny.lfx s.r0,wph:/ps;hy z3 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 theo5,fmj7c za) sir aqueous nitrate solutionjm),s fao7cz 5s:

	$XNO_3$	$Y(NO_3)_2$	$Z(NO_3)_2$
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 reacbg.4e6uc xv *t + 9p6gktag8uitions:
$Fe(s) + Cu^{2+}(aq) \rightarrow Fe^{2+}(aq) + Cu(s)$
$Fe(s) + 2Ag^+(aq) \rightarrow Fe^{2+}(aq) + 2Ag(s)$
$Zn(s) + Fe^{2+}(aq) \rightarrow Zn^{2+}(aq) + Fe(s)$
$Cu(s) + 2Ag^+(aq) \rightarrow Cu^{2+}(aq) + 2Ag(s)$

  The equation below shows the reaction between concentr3w3;abcp ;xc xe5 je/ ;zw7hapated sulfuric acid and potassium iodidh /bcx;3cx;3jeze7pww ;a pa 5e.
$8KI(s) + 5H_2SO_4(aq) \rightarrow 4K_2SO_4(aq) + 4l2(g) + H_2S(g) + 4H_2O(l)$
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 equa*khn;,-vg,o x/hl mo utions:
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