Criado por hannah ruskin
quase 9 anos atrás
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Questão | Responda |
Metals are extracted from their ores. Many copper ores contain only 2% of copper compounds. Copper is now extracted from ores containing a low percentage of copper compounds. Suggest two reasons why | Copper / ores are running out/ harder to find There are no / very small amounts of high grade copper ores left |
Suggest one reason why it is difficult to dispose of the waste rock. | Waste rock takes up a lot of space |
The reaction in the furnace could cause environmental pollution. Explain how. | Copper sulfide reacts with oxygen to produce sulfur dioxide / SO2 that causes acid rain |
The extraction of pure copper is expensive. Give one reason why. | large amounts of fuels / energy used (for the furnace and electrolysis) The extraction has many steps |
Pure copper is produced by electrolysis of copper sulfate solution. Which electrode do the copper ions move towards? Give a reason for your answer | Copper ions move towards the negative electrode / cathode because copper ions are positively charged or are oppositely charged or copper ions need to gain electrons |
Name the type of reaction that releases energy from a fuel. | Exothermic/Combustion |
Fuels react with oxygen to produce carbon dioxide. The reaction of a fuel with oxygen can produce a different oxide of carbon. Name this different oxide of carbon and explain why it is produced. | carbon monoxide / CO (is produced) because there is incomplete / partial combustion (of the fuel) |
Alloys are used to make the ballpoint pen. Give two reasons why alloys are used in the ballpoint pen. | hard / strong / durable resistant to corrosion or unreactive |
Describe, in terms of molecules, how poly(ethene) is produced. | Many monomers or many ethene molecules join / bond OR monomers / ethene molecules form chains or very large molecules |
Hydrocarbons and calcium carbonate contain locked up carbon dioxide. What is locked up carbon dioxide? | Carbon dioxide from the air / Earth’s early atmosphere formed sedimentary rocks or fossil fuels |
Describe Wegener’s idea of how Earth’s continents formed. | continents were joined together the continents then drifted apart or moved apart |
Describe how the process of fermentation is done. | sugar is mixed with / dissolved in water and yeast is added. |
Carbon neutral fuels do not increase the amount of carbon dioxide in the atmosphere. Suggest why using a biofuel, such as ethanol or rapeseed oil, is thought to be carbon neutral. | Growing sugar cane / rapeseed plants absorbs carbon dioxide which is released when the biofuel burns |
When any fuel from the table is used in a car engine, the exhaust gases contain nitrogen oxides. Explain why. | nitrogen / N2 and oxygen / O2 (in the air) react in the hot engine / at high temperature |
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