salts

Question 1

ammonia

Answer 1

• dissolves in water to produce an alkaline solution
• used to produce an ammonium salts
• ammonium salts are important in fertilisers

Question 2

ions

Answer 2

• hydrogen ions, H+ (aq) make solutions acidic and hydroxide ions make solutions alkaline
• in neutralisation reactions, hydrogen ions react with hydroxide ions to produce water: H+ (aq) + OH- (aq) –> H2O (l)

Question 3

soluble salts

Answer 3

-can be made from acids by reacting them with :
- metals- some are too reactive and some aren’t reactive enough( above hydrogen) but not Na or K
use excess metal or filter off the excess metal
- insoluble bases
- may need warming use excess insoluble base or filter of excess base
general equation: metal oxide + acid (aq) -> salt + water
general equation: metal carbonate + acid -> salt + carbon dioxide
in all the methods the salt must be crystalised
evaporate the water from the solution after filtration

Question 4

bases

Answer 4

metal oxides and hydroxides are bases. soluble hydroxides are called alkalis.
acids react with bases to form salts (neutralisation)

Question 5

precipitaion

Answer 5

• insoluble salts
• salt separated by filtration
• e.g.insoluble salt: barium sulphateions :Ba (2+) SO4 (2)solution to provide positive ion: barium nitratesolution to provide negative ion: sodium sulphate (or potassium)
  1) measure 20 ml of sodium chloride into a 100 ml beaker
  2) add 10 ml of lead nitrate
  3) gently shake and then filter through folded filter paper; wash through with distilled water
  4) remove filter paper and allow solid to dry. this is the insoluble salt