C5 GCSE mindmap
- Created by: sonalichaggar2003
- Created on: 28-02-18 17:27
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- C5-Chemical Changes
- Reactivity
- Reactivity is a measure of how easily a substance will react
- Pandas, Steal, Little, Cats, Making, Crazy, Zoos, In, Hot, Countries.
- Potassium, Sodium, Lithium, Calcium, Magnesium, Carbon, Zinc, Iron, Hydrogen, Copper
- The more reactive the metal is the faster the reaction will be. This can also be measured as more bubbles are formed every minute(rate).
- And also the more reactive the metal is the greater the temperature change will be.
- Displacement
- A more reactive metal takes the place (displaces) a less reactive metal from its compound/ from an aqueous solution of one of its salts
- Reactions of metals with water
- Metal+water = Metal hydroxide+ hydrogen
- Sodium+ water = Sodium hydroxide + Hydrogen
- Metal+water = Metal hydroxide+ hydrogen
- Dilute acids
- Metals also react with dilute acids
- Metal+Acid= Salt+ Hydrogen
- The salt has two words. The first word is the metal e.g. sodium, and the second word is the acid e.g. sulfate or nitrate or chloride
- Metal reactant is insoluble whereas the salt produced is soluble.
- Metal ores
- Metals are found in the earths crust and most are chemically combined with other elements like oxygen or sulfur
- This means they need to be extracted to get the pure metals
- Metal compounds formed underground are called ores; ores are usually metal oxides
- Extracting metals
- Metals within metal ores that are less reactive than carbon can be extracted from their ores in a displacement with carbon
- e.g. lead oxide + carbon = lead + carbon dioxide
- Carbon is a black powder but after the reaction the orange copper can be clearly seen in the black powder
- Metals that are more reactive than carbon are extracted through the process of electrolysis
- Tungsten is extracted by using hydrogen because it produces a very pure metal
- e.g. tungsten oxide + hydrogen = tungsten+ water (steam)
- Example of reduction e.g. if oxygen was lost from copperoxide
- e.g. lead oxide + carbon = lead + carbon dioxide
- Metals within metal ores that are less reactive than carbon can be extracted from their ores in a displacement with carbon
- Extracting metals
- Metals are found in the earths crust and most are chemically combined with other elements like oxygen or sulfur
- Redox reactions
- Acids are substances which form a H+ ion when in solution
- Examples are: Hydrochloric acid(HCl), Sulfuric acid(H2SO4) and Nitric acid(HNO3)
- Oxidation is the gain of oxygen but loss of electrons
- Half equation: Fe(s)=Fe2+(aq)+2e-
- Ionic equation: Fe(s)+Cu2 (aq)=Fe2+(aq)+Cu(s)
- Half equation: Cu2+(aq)+2e-=Cu(s)
- Ionic equation: Fe(s)+Cu2 (aq)=Fe2+(aq)+Cu(s)
- Half equation: Fe(s)=Fe2+(aq)+2e-
- Reduction is the loss of oxygen but gain of electrons
- Half equation: Cu2+(aq)+2e-=Cu(s)
- Species is an ion, atom or group of ions/atoms
- Mg(s)+H2SO4(aq)=MgSO4(aq)+H2(g)
- Mg is oxidised. Hydrogen is reduced. Sulfuric acid is the spectator ion (it doesn't take part in the reaction)
- Acids are substances which form a H+ ion when in solution
- Acids and bases
- The higher the concentration of H+ ions, the stronger the acid is
- A strong acid is completely ionised in aqueous solution
- A weak acid is only partially ionised in aqueous solution
- Ethanoic acid, citric acid, carbonic acid
- Acids give off H+ ions whereas alkaline give of OH- ions
- When you reduce/dilute a H+ substance (acid) by a factor of 10, its pH unit goes up by one: becomes less acidic
- Acids give off H+ ions whereas alkaline give of OH- ions
- Ethanoic acid, citric acid, carbonic acid
- A weak acid is only partially ionised in aqueous solution
- A strong acid is completely ionised in aqueous solution
- Neutralisation reaction
- Acid+Base = salt+water
- acid +metal carbonate = salt+water+ carbon dioxide
- This is called a neutralisation reaction because the products are always neutral
- H+(aq)+OH-(aq)=H20(l)
- acid +metal carbonate = salt+water+ carbon dioxide
- Acid+Base = salt+water
- The higher the concentration of H+ ions, the stronger the acid is
- PRACTICAL: obtaining a dry, pure copper salt
- How to make copper sulfate crystals from copper(II) oxide and sulfuric acid
- Sulfuric acid+copper (II)oxide = copper (II)sulfate+ water
- H2SO4(aq)+ CuO(s)+ CuSO4(aq)+ H20(l)
- Sulfuric acid+copper (II)oxide = copper (II)sulfate+ water
- 1. Add insoluble copper oxide UNTIL IN EXCESS to sulfuric acid and stir. WARM GENTLY on tripod and gauze. DO NOT BOIL.
- 2.The solution turns blue as reaction occurs. Excess copper oxide can be seen.
- 3. When no more copper oxide reacts (reaction is complete), filter out solution to remove excess copper oxide
- 4.Set up apparatus for crystallisation and perform crystallisation until you get dry crystals.
- 3. When no more copper oxide reacts (reaction is complete), filter out solution to remove excess copper oxide
- 2.The solution turns blue as reaction occurs. Excess copper oxide can be seen.
- How to make copper sulfate crystals from copper(II) oxide and sulfuric acid
- PH Scale
- To test pH, you can use: pH sensor, pH Probe attached to a pH metre, an indicator
- 0-6=acid, 7=neutral, 8-14=alkaline
- pH7,pH values more than 7 are alkaline
- Obtaining a pH curve
- pH7,pH values more than 7 are alkaline
- 1. Collect 20cm3 of sodium hydroxide in a beaker and measure its pH using a pH sensor. 2. Add acid using burette, 1cm3 at atime and measure pH of solution in beaker
- 0-6=acid, 7=neutral, 8-14=alkaline
- To test pH, you can use: pH sensor, pH Probe attached to a pH metre, an indicator
- Reactivity
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