Why does the positive anode need regular replacement in extraction of Aluminium from Al2O3?1 markAnode gains weightAnode dissolves in electrolyteAnode reacts with carbon to form carbon dioxideAnode becomes resistant to electricity

Which of the following statements is true?Metal ions always gain electrons at the anodeMetal ions always gain electrons at the cathodeMetal ions always lose electrons at the anodeMetal ions always lose electrons at the cathode2How is aluminium extracted from the earth?As an aluminium ore known as bauxiteAs pure aluminiumAs an aluminium ore known as cryoliteAs aluminium oxide3In the electrolysis of aluminium oxide, the electrodes are made of carbon in the form of graphite. Which of the following statements is not true?The presence of carbon electrodes reduces the amount of energy required for the electrolysis reactionGraphite is used as an electrode because it is a good conductor of electricityCarbon is relatively unreactive, and the electrodes do not therefore react with the aluminium oxide during electrolysisAt extremely high temperatures, the oxygen produced during electrolysis reacts with the carbon anode to form carbon dioxide4Why is molten cryolite mixed with the aluminium oxide prior to electrolysis?To act as a conductor of electricityTo increase the temperature required for the reactionTo hold the electrodes in placeTo lower the temperature required for the reaction5What is the balanced equation for the electrolysis of aluminium oxide?3Al2O3(l) → 6Al(l) + 3O2(g)2Al2O3(l) → 4Al(l) + 3O2(g)Al2O3(l) → Al(l) + O2(g)2Al2O3(l) → 3Al(l) + 4O2(g)

Electrolysis is used to extract pure aluminum from aluminum oxide based on the following reaction:2Al2O3(l) → 4Al + 3O2(g)A current of 50 amperes applied for 9 hours will extract

In the electrolysis of aluminium oxide, the electrodes are made of carbon in the form of graphite. Which of the following statements is not true?The presence of carbon electrodes reduces the amount of energy required for the electrolysis reactionGraphite is used as an electrode because it is a good conductor of electricityCarbon is relatively unreactive, and the electrodes do not therefore react with the aluminium oxide during electrolysisAt extremely high temperatures, the oxygen produced during electrolysis reacts with the carbon anode to form carbon dioxide

What material coats the negative cathode in the extraction of Alumumium from pure Aluminium oxide?1 markAluminiumZincGraphiteSilver

Explain why the positive carbon electrodes must be continually replaced.[3 marks]