Acids, Bases and Salts Flashcards
What are the properties of aqueous acids?
. They have a sour taste
. They change blue litmus to red
. They have a pH value of less than 7
. They are corrosive
. They are electrolytes
What is a salt?
A salt is a compound formed when some or all of the Hydrogen ions in an acid are replaced by metal or ammonium ions
Which acid does not react with reactive metals?
Nitric Acid HNO3
What are the reactive metals?
. Potassium
. Sodium
. Calcium
. Magnesium
. Aluminium
. Zinc
. Iron
. Lead
What does reactive metal + acid produce?
reactive metal + acid –> salt + hydrogen
What does exothermic mean?
Exothermic means that the reactions become hotter.
What does metal carbonate + acid and metal hydrogencarbonate + acid produce?
metal carbonate + acid –> salt + carbon dioxide + water
metal hydrogencarbonare + acid –> salt + carbon dioxide + water
What does metal oxide + acid or metal hydroxide + acid produce?
metal oxide + acid –> salt + water
metal hydroxide + acid – salt + water
this is a neutralisation reaction
What is a base?
A base is a proton acceptor
What is an acid?
An acid is a proton donor
What is an alkali?
An alkali is a base which dissolves in water to form a solution containing OH- ions
What are the properties of aqueous alkalis?
- They have a bitter taste
- They change red litmus to bleu
- They have a pH value of more than 7
- They are corrosive
- They are electrolytes
- They feel soapy when touched
Explain the ionisation of acids in water.
When an acid is added to water, they ionise i.e, they form ions. Acids always ionise to form H+ ions and negative anions. The H+ ions then become attached to the polar water milecules forming hydronium ions or H3O+ ions
What is an acid anhydride?
An acid anhydride is a compound which reacts with water to form an acid.
What is basicity?
Basicity is the number of H+ ions produced per molecule of acid when it dissolves in water
What can acids be classified as?
They can be classified as being organic or inorganic acids, by their basicity, as being a diluted or concentrated acid, or as being a strong and weak acid.
What is an organic acid?
Most organic acids contain the carboxyl group i.e. COOH. In these acids it is the hydrogen at the end of the carboxyl group which forms the H+ ion when it dissolves in water.
What is an inorganic acid?
An inorganic acid contains a non-metallic element or polyatomic group as well as hydrogen.
What is a monobasic, dibasic or tribasic acid?
A monobasic acid produces one H+ ion per molecule when it dissolves in water.
A dibasic acid produces two H+ ions per molecule when it dissolves in water
A tribasic acid produces three H+ ions per molecule when it dissolves in water.
What is a dilute or concentrated acid?
A dilute acid is one that contains a lot of water. A concentrated acid is one that contains very little water
What is a strong or weak acid?
A strong acid is fully ionised when dissolved in water. A weak acid is only partially ionised when dissolved in water
What is a neutralisation reaction?
A neutralisation reaction is when an acid reacts with a base to form salt and water
What is an alkali.
Bases that are soluble in water are called alkalis.
An alkali is a base which dissolves in water to form a solution containing OH- ions.
What happens to ammonia gas when it is added to water?
NH3(g) + H2O <—> NH4(g) + OH-
What is a strong and weak alkali?
A strong alkali is fully ionized when dissolved in water, a weak alkali is only partially ionised in water.
What does base + ammonium salt produce?
Base + ammonium salt —> salt + ammonia + water
What is the formula for ammonium and ammonia
Ammonium = NH4
Ammonia = NH3
What is an amphoteric substance?
An amphoteric substance is a substance which can react with both acids and with strong alkalis.
