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30 Cards in this Set
- Front
- Back
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Test for hydrogen
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test tube of hydrogen produces a "squeaky pop" with a lighted splint
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Test for oxygen
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test tube of oxygen can re-light a glowing splint
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Test for chlorine
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Bleaches the colour from damp litmus paper
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Test for ammonia
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Turns damp litmus paper blue
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Test for carbon dioxide
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Turns limewater cloudy
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What turns damp litmus paper blue?
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Ammonia
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What turns limewater cloudy?
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carbon dixoide
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What bleaches the colour from damp litmus paper?
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Chlorine
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What can re-light a glowing splint?
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oxygen
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What produces a "squeaky pop" with a lighted splint?
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hydrogen
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What does the litmus indicator colour turn for most metal oxides?
Give an example. |
Blue
Most metal oxides are basic (opposite of acidic) e.g. sodium oxide (Na₂O) forms sodium hydroxide (NaOH) when it reacts with water |
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What does the litmus indicator colour turn for most non-metal oxides?
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Red
Most non-metal oxides are acidic. e.g. sulphur trioxide (SO₃) forms sulphuric acid (H₂SO₄) when it reacts with water. |
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What are AMPHOTERIC oxides?
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Amphoteric oxides can behave like acids or bases.
e.g. aluminium oxide (Al₂O₃) can react with the alkali NaOH to form sodium aluminium hydroxide NaAl(OH)₄ or with acid HCl to form aluminium chloride AlCL₃ |
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What can you put in acidic soil?
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Neutralize it with lime (calcium oxide CaO)
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What gas from factory chimneys can cause acid rain?
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Sulphur dioxide dissolves in water from the clouds.
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What do most test for ions form?
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They form insoluble precipitates - it goes cloudy
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How do you test for Chloride Cl⁻?
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Add acidified silver nitrate
Forms white precipitate Insoluble silver chloride Cl⁻ + AgNO₃ -> AgCl(S) + NO₃⁻ |
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How do you test for sulphate SO₄²⁻?
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Acid acidified barium nitrate
Forms white precipitate Insoluble barium sulphate SO₄²⁻ + Ba(NO₃)₂ -> BaSO₄(S) + 2NO₃⁻ |
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How do you test for carbonate
CO₃²⁺? |
Add acid and bubble the gas formed in limewater
Gas turns limewater cloudy |
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How do you test for nitrate NO₃⁻?
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Boil with sodium hydroxide and aluminium foil. Test gas with damp red litmus paper.
Litmus paper turns blue. |
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How do you test for Copper (II) Cu²⁺?
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Add sodium hydroxide followed by ammonia solution.
Blue precipitate dissolves when ammonia is added. |
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How do you test for Iron (II) Fe²⁺?
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Add sodium hydroxide followed by ammonia solution.
Green precipitate forms. Ammonia does NOT dissolve it. (stays insoluble) |
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How do you test for Iron (III) Fe³⁺?
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Add sodium hydroxide followed by ammonia solution.
Brown precipitate forms. Ammonia does NOT dissolve it. (stays insoluble) |
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How do you test for Zinc Zn²⁺?
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Add sodium hydroxide followed by ammonia solution or more sodium hydroxide.
White precipitate forms. It is soluble in both ammonia or more sodium hydroxide. |
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What happens when you test for carbonate ions CO₃²⁻?
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Acid reacts with carbonate to form carbon dioxide gas which reacts with limewater to form insoluble calcium carbonate
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What happens when there is a positive test for nitrate ions NO₃⁻?
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The nitrate gets reduced by aluminium (a strong reducing agent) and forms ammonia.
Ammonia is an alkali so turns the red litmus paper blue. |
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What happens when there is a positive test for Copper (II) Cu²⁺?
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Insoluble copper (II) hydroxide is forms.
Cu²⁺ + 2NaOH -> Cu(OH)₂(S) + 2Na⁺ When ammonia is added a soluble complex forms so the precipitate (Cu(OH)₂) dissolves. |
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What happens when there is a positive test for iron (II) Fe²⁺?
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Insoluble iron (II) hydroxide is forms.
Fe²⁺ + 2NaOH -> Fe(OH)₂(S) + 2Na⁺ Ammonia does not react with iron (II) hydroxide so does NOT dissolve. |
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What happens when there is a positive test for iron (III) Fe³⁺?
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Insoluble iron (III) hydroxide is forms.
Fe³⁺ + 3NaOH -> Fe(OH)₃(S) + 3Na⁺ Ammonia does not react with iron (II) hydroxide so does NOT dissolve. |
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What happens when there is a positive test for zinc Zn²⁺?
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Insoluble zinc hydroxide forms.
Zn²⁺ +⁺ 2NaOH -> Zn(OH)₂(S) + 2Na⁺ Both ammonia and sodium hydroxide react with zinc hydroxide to form a soluble complex. |
