Flashcards
National 5 Chemistry-Metals
Cards in this deck (27)
- 1Between what does metallic bonding occur?Between the atoms of metal elements.
- 2Explain what metallic bonding isThe outer electrons are delocalised (free to move). This produces an electrostatic force of attraction between the positive metal ions and the negative delocalised electrons, which acts as a glue holding the atoms together.
- 3Can metals conduct electricity?Yes, because the electrons are delocalised, and since electricity is the flow of electrons. For example in power supply, as one electron moves into the metal another will jump off the metal. Throughout this, the metal will stay completely unchanged as it always has the same amount of electrons.
- 4What happens when a metal reacts with water?Most metals don't react with water, but some of the more reactive metals do, eg. the alkali metals. Gold, silver and platinum don't react with water at all because they are unreactive metals.
- 5What happens when a metal reacts with an acid?Only the more reactive metals react with acids. Only the metals above hydrogen in the reactivity series react with an acid because all acids contain H+ ions. Gold and platinum are unaffected.
- 6What happens when a metal reacts with oxygen?Only the most reactive metals react strongly with oxygen.
- 7What is the reactivity series?A list of elements listed in order of reactivity, starting with the most reactive. Electrons flow from the most reactive metal (oxidation), to the least reactive metal (reduction).
- 8Why is a flow of electrons produced?Because of the difference in reactivity of the two metals. Electricty is made when this happens.
- 9What is a cell (battery) made up of?Two different metals connected by an electrolyte (an ionic solution that is used to complete a circuit).
- 10What happens the further apart the metals are in the reactivty series?A higher voltage is produced.
- 11Name another way a cell can be producedBy connecting two different metals in a solution of their own ions. To complete the circuit an ion bridge must be used. This can simply be a piece of filter paper soaked in salt water, or some other ionic solution
- 12Explain what a fuel cell isA device that converts chemical energy, from a fuel such as hydrogen, into electrical energy through a chemical reaction with oxygen or some other oxidising agent. Water is the only by-product. However, hydrogen gas is difficult to store and is explosive.
- 13Give an example of a rechargeable battery, and why are we able to re-use it?Lead-acid battery, found in cars. Reversing the direction of the electrical flow in a rechargable battery reverses the chemical reaction that occured in the battery in the first place, making it ready for use again.
- 14What is a displacement reaction?A reaction where a reactive metal displaces a metal that is less reactive in a solution. The most reactive metal will always join to the group ion. If the group ion is already combined to the most reactive metal, then no reaction will occur.
- 15What is an oxidation reaction?A oxidation reaction occurs when substances lose electrons.
- 16What is a reduction reaction?A reduction reaction occurs when substances gain electrons.
- 17What is a redox reaction?A redox reaction is one where both oxidation and reduction take place.
- 18Give an example of a redox reactionAll displacement reactions are redox reactions because one metal is gaining (reduction) and metal is loosing electrons (oxidation). A cell is another example of a redox reaction.
- 19Explain what a metal ore isA compound of a metal that is found in the Earth's crust. Only gold and platinum are found as a pure metal since they are very unreactive. All the other metals have to be removed from their ores. The more reactive the metal is, the more difficult.
- 20How are the metals from Potassium to Aluminium removed from their ores?The more reactive metals require electrolysis.
- 21How is zinc removed from its ore?By using heat and a reducing agent (a substance that can donate electrons) such as carbon or carbon monoxide.
- 22How is iron removed from its ore?Blast furnace
- 23How are tin lead and copper removed from their ores?Heat plus carbon or monoxide.
- 24How are mercury, silver and gold removed from their ore?By heat alone.
- 25What is the corrosion?The deterioration of a metal, which results from a chemical reaction with its environment. Rust is the term specifically used for the corrosion of iron. Ferroxyl indicator shows the early signs of rusting.
- 26What must be present for corrosion to take place?Both water and oxygen. Acid and salt will speed up the rate of corrosion.
- 27What is an alloy?A mixture of metals or with non-metals to make a metal more useful for a specific use.
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- CfE Higher Chemistry (Unit 3-Chemistry and Society) Flashcards on National 5 Chemistry-Metals, created by NinaJasT on 09/03/2015.
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