Identify the anode as the site of oxidation and the cathode as the site of reduction in any electrochemical cell, and assign electrode signs: anode negative and cathode positive in a voltaic cell, the reverse in an electrolytic cell.
Tę umiejętność sprawdza 29 zadań wzorowanych na arkuszach IB z lat 2022–2026.
Many rechargeable batteries use an alkaline electrolyte. In the nickel-cadmium cell, cadmium, Cd, is the anode. Cd(OH)2(s) + 2 e− → Cd(s) + 2 OH−(aq) NiO(OH)(s) + H2O(l) + e− → Ni(OH)2(s) + OH−(aq) Deduce the overall reaction for the cell.
Iron and nickel can be used to design a voltaic cell. Fe(s) + Ni2+(aq) → Fe2+(aq) + Ni(s) (i) Annotate the diagram with the appropriate electrodes, electrolyte solutions and the direction of electron flow. (ii) The redox reactions in some voltaic…
Which option describes the electrode reactions in a hydrogen fuel cell with an acidic electrolyte? 2 H2(g) + O2(g) → 2 H2O(l) A. Cathode: hydrogen is oxidized; anode: oxygen is reduced B. Cathode: oxygen is reduced; anode: hydrogen is oxidized C.…
Which combination is correct for this cell, when nickel is more reactive than silver? A. Cathode: silver; anode: nickel; sign on cathode: -; sign on anode: + B. Cathode: nickel; anode: silver; sign on cathode: -; sign on anode: + C. Cathode: nickel; anode:…
A voltaic cell is represented by the cell diagram below. Which species is produced at the cathode? Ni(s) ∣ Ni2+(aq) ∣∣ Ag+(aq) ∣ Ag(s) A. Ni(s) B. Ni2+(aq) C. Ag+(aq) D. Ag(s)
A student proposed that, because tin(IV) iodide might be ionic, electrolysing the molten compound with inert electrodes should regenerate tin and iodine. (i) Label the diagram of the electrolytic cell to show which electrode is the anode and which is the…
Zinc displaces copper from aqueous copper(II) sulfate solution, as shown in the voltaic cell below. Which row correctly gives the sign and the electrode type of the zinc electrode in this cell? In each option the sign is given first and the electrode type…
Molten lead(II) bromide, PbBr2(l), is electrolysed using inert electrodes. Which products form at the electrodes? A. Anode: Br2, cathode: Pb B. Anode: O2, cathode: Pb C. Anode: Pb, cathode: Br2 D. Anode:…
(i) Deduce the condensed electron configuration of chlorine. (ii) Describe the bonding in a molecule of chlorine in terms of valence electrons. (iii) Explain why chlorine has a much lower boiling point than bromine, although both exist as simple diatomic…
Magnesium is a stronger reducing agent than lead. A voltaic cell is constructed using magnesium and lead electrodes dipped into solutions of their respective ions, Mg2+(aq) and Pb2+(aq), of equal concentrations. What is correct when the…
Molten potassium iodide is electrolysed. Write the half-equation for the reaction at each electrode: the positive electrode (anode) and the negative electrode (cathode).
Which statement is correct for a voltaic cell made from a zinc half-cell and a copper half-cell? The standard electrode potential of the zinc half-cell is more negative than that of the copper half-cell. A. Zinc is the cathode. B. Electrons flow through the…
Zinc lies above nickel in the reactivity series. A voltaic cell is made from a zinc electrode in Zn2+(aq) and a nickel electrode in Ni2+(aq). The electrodes are connected by a wire with a voltmeter, and the two solutions are connected by a salt…
An electrolytic cell is made using inert electrodes and molten calcium chloride, CaCl2(l). State the half-equation for the reaction occurring at each electrode. Anode (positive electrode): Cathode (negative electrode):
A voltaic cell is constructed from a half-cell of metal A in a solution of A2+ ions and a half-cell of metal B in a solution of B2+ ions. The half-cells are joined by a salt bridge and an external wire. Metal B is the more reactive metal. What…
Sketch the voltaic cell that would produce the greatest cell potential (EMF) using the metals and solutions in this experiment. On your diagram label the metal and the solution in each half-cell, the anode, the cathode, the salt bridge and the direction of…
Deduce the products formed at each electrode during the electrolysis of molten magnesium iodide, MgI2. Anode (positive electrode): Cathode (negative electrode):
Molten lithium bromide, LiBr(l), is electrolysed using inert graphite electrodes, as shown in the diagram. (i) Identify the product formed at the cathode. (ii) State the direction in which the electrons flow in the external circuit, referring to the…
A voltaic cell was constructed from an iron(II) sulfate/iron half-cell and a copper(II) sulfate/copper half-cell, connected by a salt bridge and, externally, by a wire. (i) Outline why electrons flow from the iron half-cell to the copper half-cell when the two…
Which row describes an electrolytic cell? A. The anode is positive; the overall reaction is non-spontaneous B. The anode is negative; the overall reaction is spontaneous C. The anode is negative; the overall reaction is non-spontaneous D. The anode is…
Aluminium has a low density, which is why it is widely used in aircraft and in specialized alloys. Aluminium is produced industrially by the electrolysis of aluminium oxide dissolved in molten cryolite, as shown in the diagram. (i) Outline why the molten…
Aluminium is a low-density metal that is used in lightweight alloys. Aluminium is produced by the electrolysis of molten aluminium oxide (in industry dissolved in molten cryolite to lower the operating temperature). A simplified cell is shown in the diagram.…
A voltaic cell is set up with the cell diagram and a salt bridge containing aqueous potassium nitrate. Which statements are correct while the cell operates? I. The mass of the silver electrode…
A voltaic cell consists of a zinc electrode in aqueous zinc sulfate and a copper electrode in aqueous copper(II) sulfate, joined by an external circuit and by a salt bridge containing aqueous potassium nitrate. What occurs during the operation of the cell? I.…
Which statement is correct for the cathode in both a voltaic cell and an electrolytic cell? A. It is the positive electrode B. It is the negative electrode C. Anions move towards it D. Reduction takes place at it
A battery is connected in a circuit. The arrows show the direction of electron flow. What does terminal X of the battery represent? A. Anode and positive terminal B. Anode and negative terminal C. Cathode and positive terminal D. Cathode and negative terminal
The diagram shows an unlabelled voltaic cell for the reaction: Ni(s) + 2 Ag+(aq) → Ni2+(aq) + 2 Ag(s) (i) Identify, using species from the equation, what W, X, Y and Z are, and state the direction of electron flow in the external circuit. (ii) Write the…
A voltaic cell is based on the reaction Zn(s) + Ni2+(aq) → Zn2+(aq) + Ni(s) The half-cells are connected by a salt bridge containing aqueous potassium nitrate. What happens when the cell operates? A. Electrons flow from Ni to Zn; anions in the…
Molten lead(II) bromide is electrolysed using inert graphite electrodes connected to a DC power supply. Bromine forms at one of the electrodes. Which row is correct for the electrode where bromine forms? A. Anode; positive electrode; electrons leave this…
Zapisujemy na Twoim urządzeniu to, bez czego serwis nie działa, np. zalogowanie. Plików analitycznych użyjemy tylko za Twoją zgodą. Szczegóły w polityce prywatności.