C2.6 Flashcards
What is the pH of an acid?
Lower than 7
What are ammonium salts used for?
~ Artificial fertilisers
~ They’re used for this because ammonium contains nitrogen which is important to make amino acids which make proteins for growth
What does the symbol (aq) stand for?
Aqueous
What salt is made when magnesium reacts with hydrochloric acid?
Magnesium chloride (+hydrogen)
What are the products of the reaction between an acid and a metal?
Salt + hydrogen
What are the products of the reaction between an acid and an alkali?
Salt + water
What is the symbol equation for a neutralisation reaction?
H+(aq) + OH-(aq) -> H2O(l)
What are soluble bases?
Alkalis
What happens when acids and alkalis dissolve in water?
They dissociate into their individual ions
What do acids dissociate to produce?
H+ ions in solution
What do alkalis dissociate to produce?
OH- ions in solution
What do hydrogen ions (H+) do to solutions?
Makes them acidic
What do hydroxide ions (OH-) do to solutions?
Makes them alkaline
How can soluble salts be made?
By acids reacting with metals, insoluble bases and alkalis
What is formed when some metals react with dilute acid?
A metal + salt + hydrogen
How can insoluble salts be made?
~ By mixing appropriate solutions of ions together
~ Or by reacting two soluble salts in a precipitation reaction
What can precipitation be used for?
Removing unwanted ions from solution (e.g. Softening hard water)
What are calcium ions precipitated out as?
Insoluble calcium
What happens in a precipitation reaction?
A solid substance is formed as a result of two solutions reacting together
How do you remove the solid precipitate? (After reacting it with the 2 solutions)
~ Filter it
~ Wash with distilled water
~ Dry out the solid
What are the uses of precipitation reactions?
Treating effluent from factories (removing toxic ions before the effluent is released into the environment)
What does aqueous mean?
Dissolved in water (in solution)
Acid + insoluble base ->
Salt + water
What is the process of making salt and water by reacting an acid with an insoluble base?
~ React them until the reaction stops
~ Filter it
~ Evaporate it down and leave it for a few days to form the crystals
What is the process of making salt and water by reacting an acid with an alkali?
~ Add acid into alkali with indicator until inductor turns green
~ Repeat experiment without indicator by adding the same amount of acid
~ Evaporate it down and leave it for a few days to form to crystals
What salt does hydrochloric acid make?
A chloride
What salt does sulphuric acid make?
A sulphate
What salt does nitric acid make?
A nitrate
What are some examples of bases?
~ Metal oxides
~ Metal hydroxides
What do you use to measure the pH scale?
Universal indicator
What is the name of the reaction when an acid reacts with an alkali?
Neutralisation reaction
What type of reaction is making ammonium salts?
Neutralisation reaction
Why may not all metals be suitable to react with acids?
If they’re too reactive or not reactive enough
Salt solutions can be crystallised to produce what?
Solid salts
What are metal oxides and hydroxides?
Bases
The salt produced in any reaction between an acid and a base or alkali depends on what?
~ The acid used
~ The metal in the base or alkali
What is the difference between an alkali and a base?
All alkalis are bases, but only soluble bases are alkalis
