C8) Acids, Bases and Salts Flashcards
What is the flame colour for lithium? (flame test)
red
What is the flame colour for sodium? (flame test)
yellow
What is the flame colour for potassium? (flame test)
lilac
What is the flame colour for copper? (flame test)
blue-green
What is the test for ammonia? (test for gases)
turns damp red litmus paper blue
What is the test for carbon dioxide? (test for gases)
turns limewater milky
What is the test for chlorine? (test for gases)
bleaches damp litmus paper
What is the test for hydrogen? (test for gases)
pops with a lighted splint
What is the test for oxygen? (test for gases)
relights a glowing splint
What is the test and result for carbonate? (test for anions)
- add dilute acid
- effervescence, carbon dioxide produced
What is the test and result for chloride? (test for anions)
- acidify with dilute nitric acid, then add aqueous silver nitrate.
- white ppt.
What is the test and result for bromide? (test for anions)
- acidify with dilute nitric acid, then add aqueous silver nitrate.
- cream ppt.
What is the test and result for nitrate? (test for anions)
- add aqueous sodium hydroxide, then aluminium foil; warm carefully.
- ammonia produced.
What is the test and result for sulfate? (test for anions)
- acidify, then add aqueous barium nitrate.
- white ppt.
What is the effect of ammonium on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- ammonia produced on warming.
- –
What is the effect of calcium on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- white ppt., insoluble in excess.
- no ppt. or very slight white ppt.
What is the effect of copper on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- light blue ppt., insoluble in excess.
- light blue ppt., soluble in excess, giving a dark blue solution.
What is the effect of iron (II) on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- green ppt., insoluble in excess.
- green ppt., insoluble in excess
What is the effect of iron (III) on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- red-brown ppt., insoluble in excess.
- red-brown ppt., insoluble in excess.
What is the effect of zinc on 1.aqueous sodium hydroxide & 2.aqueous ammonium? (test for cations)
- white ppt., soluble in excess, giving a colourless solution.
- white ppt., soluble in excess, giving a colourless solution.
What is pH of acids?
below 7
what is the pH of bases?
above 7
give 3 properties of bases.
- slippery in touch.
- bitter in taste.
- pH above 7.
give 3 properties of acids.
- sour taste (when edible)
- are corrosive
- pH below 7.
State the colour indicator of acids and bases for litmus paper.
- acids : turn litmus paper red.
- bases : turn litmus paper blue.
Give the equation for the reaction of acids with metal.
Acid + Metal → Salt + Hydrogen
Give the equation for the reaction of acids with bases.
Acid + Base → Salt + Water
Give the equation for the reaction of acids with metal carbonates.
Acid + Metal Carbonate → Salt + Carbon Dioxide + Water
Give the equation for the reaction of bases with ammonium salt.
Base + Ammonium salt → Salt + Ammonia + Water
What is an acid?
An acid is a substance that produces hydrogen ions, H +(aq), when dissolved in water
What is a base?
An alkali is a substance that produces hydroxide ions, OH -(aq), when dissolved in water.
What is the importance of controlling acidity in soil?
If it is too alkaline or acidic, the crops won’t grow properly. Acidity is usually the problem for soil, so a base can help neutralise it. Bases like limestone, slaked lime, or quick lime are usually sprayed in the soil to neutralise it before planting crops.
What is the pH number and colour for neutral?
- 7
- green
what pH colour is a strong acid?
red
what pH colour is a strong base?
dark blue/purple
how are acidic oxides formed?
when a non-metal element combines with oxygen
how are basic oxides formed?
when a metal element combines with oxygen
what are neutral oxides?
oxides that do not react with either acids, nor bases.
what are amphoteric oxides?
oxides that can behave as both acidic and basic depending on whether the other reactant is an acid or a base.