Which of the following statements about ‘inert’ electrodes is not true?At the cathode, positive ions gain electrons to become metal elementsThey take part in the electrolysis reactionsThey can be made of carbonAt the anode, negative ions lose electrons and become non-metal elements2Copper can be purified by electrolysis using metal (non-inert) electrodes. Which of the following correctly describes how the electrolysis cell should be set up?Cathode should be impure copper, anode should be pure copperCathode should be carbon, anode should be impure copperCathode should be pure copper, anode should be carbonCathode should be pure copper, anode should be impure copper3What happens at the anode?Copper ions formCopper atoms formSulfate ions formImpurities from the impure copper are collected4What happens at the cathode?Impurities from the impure copper are collectedCopper ions formSulfate ions formCopper atoms form5The core practical investigates the changes in electrode mass during the electrolysis of copper sulfate solution at different currents. Which of the following would you not expect to happen?The higher the current the lower the change in mass between the anode and cathodeThe anode decreases in massThe gain in mass by the cathode is the same as the loss in mass by the anodeThe cathode increases in mass6Sometimes the mass gain at the cathode may be slightly lower than the mass loss at the anode. What is an explanation for this?Some of the propanone used in the washing process may not have evaporated properly from the anodeAll of theseSome of the copper deposited at the cathode may have fallen off during the washing processIf the anode is not pure copper, any impurities will be deposited in the electrolyte rather than at the cathode
Question
Which of the following statements about ‘inert’ electrodes is not true?At the cathode, positive ions gain electrons to become metal elementsThey take part in the electrolysis reactionsThey can be made of carbonAt the anode, negative ions lose electrons and become non-metal elements2Copper can be purified by electrolysis using metal (non-inert) electrodes. Which of the following correctly describes how the electrolysis cell should be set up?Cathode should be impure copper, anode should be pure copperCathode should be carbon, anode should be impure copperCathode should be pure copper, anode should be carbonCathode should be pure copper, anode should be impure copper3What happens at the anode?Copper ions formCopper atoms formSulfate ions formImpurities from the impure copper are collected4What happens at the cathode?Impurities from the impure copper are collectedCopper ions formSulfate ions formCopper atoms form5The core practical investigates the changes in electrode mass during the electrolysis of copper sulfate solution at different currents. Which of the following would you not expect to happen?The higher the current the lower the change in mass between the anode and cathodeThe anode decreases in massThe gain in mass by the cathode is the same as the loss in mass by the anodeThe cathode increases in mass6Sometimes the mass gain at the cathode may be slightly lower than the mass loss at the anode. What is an explanation for this?Some of the propanone used in the washing process may not have evaporated properly from the anodeAll of theseSome of the copper deposited at the cathode may have fallen off during the washing processIf the anode is not pure copper, any impurities will be deposited in the electrolyte rather than at the cathode
Solution
The text you provided contains multiple questions related to electrolysis and copper purification. Here are the answers:
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The statement about 'inert' electrodes that is not true is "They take part in the electrolysis reactions". Inert electrodes do not participate in the reactions, they only provide a surface for the reactions to occur.
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For purifying copper by electrolysis using metal (non-inert) electrodes, the correct setup is "Cathode should be impure copper, anode should be pure copper". The impure copper is reduced (gains electrons) at the cathode to become pure copper, while the pure copper anode is oxidized (loses electrons) to become copper ions.
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At the anode, "Copper ions form". The copper atoms from the anode lose electrons and become copper ions.
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At the cathode, "Copper atoms form". The copper ions gain electrons to become copper atoms.
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You would not expect "The higher the current the lower the change in mass between the anode and cathode". The higher the current, the greater the change in mass as more reactions occur.
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The explanation for the mass gain at the cathode being slightly lower than the mass loss at the anode could be "All of these". Some propanone may not have evaporated properly, some copper may have fallen off during washing, and if the anode is not pure copper, impurities will be deposited in the electrolyte.
Similar Questions
Which of the following statements is true?Metal ions always lose electrons at the cathodeMetal ions always lose electrons at the anodeMetal ions always gain electrons at the cathodeMetal ions always gain electrons at the anode2How is aluminium extracted from the earth?As an aluminium ore known as cryoliteAs an aluminium ore known as bauxiteAs aluminium oxideAs pure aluminium3In 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 reactionAt extremely high temperatures, the oxygen produced during electrolysis reacts with the carbon anode to form carbon dioxideGraphite 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 electrolysis4Why is molten cryolite mixed with the aluminium oxide prior to electrolysis?To increase the temperature required for the reactionTo hold the electrodes in placeTo act as a conductor of electricityTo lower the temperature required for the reaction5What is the balanced equation for the electrolysis of aluminium oxide?2Al2O3(l) → 3Al(l) + 4O2(g)Al2O3(l) → Al(l) + O2(g)2Al2O3(l) → 4Al(l) + 3O2(g)3Al2O3(l) → 6Al(l) + 3O2(g)
At which electrode does oxidation occur in a voltaic cell?Group of answer choicesanode onlyeither anode or cathode, depending on the metalboth anode and cathodecathode only
Which statement is correct for a voltaic but not for an electrolytic cell?A. An electrolyte is required.B. The anode is where oxidation occurs.C. Ions move in the electrolyte.D. Electrons flow from the negative electrode to the positive electrode
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Consider the following statements about cathode rays:(a) They are negatively charged particles(b) The characteristics of cathode rays do not depend upon the material of electrodes used.(c) They start from anode and move towards cathode.The correct statements are:
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