Fichas
C2.5
Fichas del conjunto (34)
- 1Which ions are produced by acids when they are added to water?Hydrogen ions, H+(aq)
- 2What is an alkali?A soluble base or a substance that produces hydroxide ions in solution
OH-(aq) - 3Which indicators can tell us the pH of a solution?Universal indicator or full-range indicators
- 4Name a metal other than zinc that can safely react with an acid to produce a saltAny metal that is more reactive than hydrogen, but less reactive than calcium, e.g. lead, tin, iron, aluminium, magnesium
- 5Why do we add excess of the base when making a salt?To use up all of the acid or to neutralise all of the acid
- 6Name the products when nitric acid reacts with magnesiuMagnesium nitrate and hydrogen
- 7Name the products when hydrochloric acid reacts with copper hydroxideCopper chloride chloride and water
- 8What compound is produced in every neutralised reaction?Water H2O
- 9Zinc carbonate is insoluble in water. What would happen when sodium carbonate solution is added to zinc sulfate solution?Zinc carbonate would be produced as a precipitate or solid, sodium sulfate would remain in the solution
- 10What must be done to ionic compounds before they can be electrolysed?They must be melted or dissolved in water
- 11Molten zinc chloride is electrolysed. Name the substances produced at the positive electrodeChlorine
- 12Molten zinc chloride is electrolysed. Name the substances produced at the negative electrodeZinc
- 13What type of change happens at the negative electrode when sodium ions become sodium atoms?Reduction or positive sodium ions gain electrons
- 14Complete the half equation for the formation of chlorine at a positive electrode: 2Cl- -> .... + ....2Cl- -> Cl2 + 2e-
- 15Name the products at the positive electrodes when aqueous copper sulfate solution is electrolysed using carbon electrodesOxygen
- 16Name the products at the negative electrodes when aqueous copper sulfate solution is electrolysed using carbon electrodesCopper
- 17Why is aluminium oxide mixed with with cryolite in the electrolysis cell?To lower the melting temperature
- 18What are the final products of the electrolysis cell?Aluminium and carbon dioxide
- 19Why is hydrogen produced when sodium chloride solution is electrolysed?The solution contains hydrogen ions which are discharged in preference to sodium ions because sodium is more reactive than hydrogen
- 20Why is the electrolysis of brine an important industrial process?It's (three) products have many uses or can be used in many ways
- 21Why are some knives, forks and spoons silver-plated?To make them look attractive, to protect the metal from corrosion, to reduce the cost (of making the items from pure silver)
- 22Describe how you would silver plate a small piece of copper jewelleryPass electricity through a cell with the item of jewellery as the negative electrode, the positive electrode made of silver and containing a solution of a silver salt (e.g. silver nitrate solution) (as the electrolyte)
- 23Dilute nitric acid is added to sodium hydroxide solution. What type of substance is sodium hydroxide?An alkali
- 24Dilute nitric acid is added to sodium hydroxide solution. What type of reaction happens?Neutralisation
- 25Dilute nitric acid is added to sodium hydroxide solution. Why is an indicator used to show when the reaction is complete?There is no visible change and it will show when the pH is 7
- 26Dilute nitric acid is added to sodium hydroxide solution. Write a word equation for the reactionNitric acid + sodium hydroxide -> sodium nitrate + water
- 27Describe the main steps to make zinc sulfate crystals from zinc oxide and dilute sulphuric acidAdd zinc oxide, a little at a time, to dilute sulfuric acid, until there is an excess, filter off the excess, evaporate some of the water, leave to cool and crystallise
- 28Describe how you could make some insoluble lead sulfate from solutions of lead nitrate and sodium sulfateMix the two solutions, filter the mixture or leave to settle and decant or centrifuge and decant to separate the solid (precipitate). Then wash with distilled water and dry
- 29Why are some items of jewellery made of gold-plated nickel?Less expensive than pure gold, to improve appearance, so they do not corrode (or cause allergic reactions)
- 30Name the products when sodium chloride solution is electrolysed and give one use for eachHydrogen, chlorine and sodium hydroxide. A use for each, e.g. hydrogen: to make hydrochloric acid, margarine manufacture, fuel; chlorine: to make bleach, plastics; sodium hydroxide: to make soap, paper, as a cleaning agent (ovens/drains)
- 31Aluminium is manufactured from aluminium oxide, Al2O3, which is inexpensive. Why is manufacturing aluminium an expensive process?It needs: Large amounts of electricity, high temperature to melt the aluminium oxide
- 32Aluminium is manufactured from aluminium oxide, Al2O3, which is inexpensive.To lower the melting/operating temperature (of the electrolyte
- 33Explain as fully as you can what happens at the electrodes when molten sodium chloride is electrolysedAt the negative electrode: Sodium ions gain electrons, are reduced, to sodium atoms/metal. At the positive electrode: chloride ions lose electrons, are oxidised, to chlorine atoms, which form chlorine molecules/gas
- 34Write half equations for the reactions at the electrodes when magnesium chloride solution MgCl2(aq) is electrolysed using carbon electrodesAt the negative electrode:
2H+ + 2e- --> H2
At the positive electrode:
2Cl- --> Cl2 + 2e-
Información
- Descripción
- GCSE (Unit 2) Chemistry Fichas sobre C2.5, creado por Mel Hughes el 31/08/2016.
- Creado por
- Mel Hughes
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