Half-equations and balancing redox equations

(i) State the independent variable and the dependent variable of the investigation. (ii) Apart from the mass of leaves and the volume of water, suggest two other conditions that should be kept constant for the comparison between boiling times to be valid.…

In a molten carbonate fuel cell the mixture of hydrogen and carbon dioxide from the reaction is fed to the anode, while a mixture of oxygen and carbon dioxide is fed to the cathode. Carbonate ions, $\ce{CO3^2-}$, move through the molten electrolyte from the…

In the first step, manganese(III) ions formed from the manganate(VII) are complexed by ethanedioate ions. $\ce{[Mn(H2O)6]^3+(aq) + 2C2O4^2-(aq) -> [Mn(C2O4)2(H2O)2]^-(aq) + 4H2O(l)}$ (i) Deduce the oxidation state of carbon in $\ce{[Mn(C2O4)2(H2O)2]^-}$. (ii)…

During discharge, sodium atoms stored in the hard carbon are converted into sodium ions. (i) State the half-equation for the process taking place at the anode while the battery discharges. (ii) With reference to section 19 of the data booklet, comment on the…

A total charge of 1500.0 C flows through the external circuit during one discharge of the battery. Determine how many sodium ions are released at the anode. Use section 2 of the data booklet.

A steel object is electroplated with nickel, using an aqueous nickel(II) chloride electrolyte. (i) Deduce the half-equation for the reaction occurring at each electrode. Anode: Cathode: (ii) For the reaction between chlorine gas and aqueous potassium iodide…

Which half-equation represents the reduction of sulfuric acid to sulfur dioxide in acidic solution? A. $\ce{H2SO4 + 2H+ + 2e- -> SO2 + 2H2O}$ B. $\ce{H2SO4 + 4H+ + 4e- -> SO2 + 2H2O}$ C. $\ce{H2SO4 + 2H2O -> SO2 + 6H+ + 2e-}$ D.…

Below is a sodium-ion cell as it discharges, supplying a current to an external circuit. The anode is sodium held in a lattice of hard carbon and the cathode is iron(III) phosphate, $\ce{FePO4}$, which is converted to $\ce{NaFePO4}$ as the cell discharges.…

In a redox titration, dichromate(VI) ions are reduced to chromium(III) ions and iron(II) ions are oxidized to iron(III) ions. $\ce{Cr2O7^2-(aq)}$ reduced to $\ce{Cr^3+(aq)}$ $\ce{Fe^2+(aq)}$ oxidized to $\ce{Fe^3+(aq)}$ What volume of…