Chemistry C7 Ideas in context possible questions

all the possible questions for the ideas in context chemistry exam C7

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  • Created by: callum
  • Created on: 25-05-11 15:04

- Why is lithium called an Alkali metal ? Becasue when it reacts with water it makes an alkali due to hydroxide ions.

- what is an ion? Atom or group of atoms with a charge.

- How are ions formed? Atoms lose an electron to form positive ions and gain an electron to fom negative ions.

- what is the short hand electronic configuration for lithium atom and ion? Li = 2,1 Li+ = 2,0

- what is the charge of a carbonate ion? CO32-

- what is the formula for lithium carbonate? Li2 CO3

- symbol equation for Lithium carobonate and hydrochloric acid reaction?               Li2CO3 (s) + 2HCl (aq) ---> 2LiCl (aq) + CO2 (g) + H2O (l) 

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- what is an Ore ? Rock that contains a high amount of mineral (metal compound)

-what do you predict to happen to lithium prices in the future ? The price will increase, as demand will increase and the amount of lithium will decrease causing prices to rise.

- what are the stages in a life cycle of a metal ? crush ore----> purify the mineral     ----->extract metal from ore----->use metal----->recycle metal----> metal to landfill.

- What is an ionic bond? Electrostatic attraction between positive and negative ions

- Explain how lithium chloride dissolves in water? Lithium chloride separates into positive lithium ions and negative chloride ions, each ion gets surrounded by water and is free to move.

- What are the different ways of extracting metals? extracting by digging pure metal ( gold), extract using carbon ( iron), extract by electrolysis ( sodium).

- What determines which method is used? How reactive the metal is

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- what is oxidation? The reaction when a chemical gains oxygen during a reaction

- Explain how electrolysis works? The compounds must be liquid so the negative ions can move to the positive electrode where they lose electrons to become atoms. The positive ions go to the negative electrode where they gain electrons to become atoms.

- In terms of electrons what happens at the electrodes during electrolysis? Negative ions lose electrons and positive ions gain electrons to become atoms.

- what is an electrolyte? This is the molten ( liquid ) ionic compound which is being separated.

- During electrolysis why is the electrolyte molten? So the ions are free to move.

- Explain why electrolysis is an expensive process? Lots of energy is needed to melt the ionic compound due to strong ionic bonds.

- Why is electrolysis a 24/7 process? To reduce cost by keeping the electrolyte molten at all times.

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- What pollution is caused during electricity generation? Carbon dioxide from burning fossil fuels. sulphur doixide (so2) from sulphur impurities in fossil fuels.

- What are the environmental problems associated with mining and extracting metals? Scar the countryside, can pollute the air, carbon dioxide, suphur dioxide.

- How could placing lithium in landfills be an environmental problem? Lithium is extremely toxic and could leak into water supplies or be absorbed by plants roots and passed on via food chains.

- Why do elements in group one ave similar chemical properties? They have the same number of electrons in their outer shell.

- Why are group 1 elements very reactive? Because they have only one electron i their outer shell which they lose very quickly.

- Explain why group 1 metals are stored under oil? Because they react quickly with oxygen and water in the air. They do not react with oil.

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- During the reaction of Lithium and water what would you observe? Lithium would move around top of water and gas would be released. 

- Why are group 1 metals called the Alkali metals? Because when they react with water they make lots of hydroxide ions ( OH- ) causing the PH to be very Alkaline.

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