Flashcards in Acids Deck (33)
Name 4 common acids
What is an acid?
A species that is a proton donor
Why is an acid a proton donor?
They release H+ ions (protons) when dissolved in water
Name a strong acid
What makes an acid a strong acid?
When it dissolves, all of the acid molecules dissociate to release H+ ions
Name a weak acid
What makes an acid a weak acid?
When is dissolves, only a small proportion of the acid molecules dissociate to release H+ ions
Name 3 common bases
What are general bases?
Metal oxides and metal carbonates
What are bases?
A species that is a proton acceptor
What do bases do?
Accept protons donated by the acid
What are alkalis?
A type of base that dissolves in water forming OH- ions
Name a strong base
What makes a strong base a strong base?
When it dissolves, all of its OH- ions are available to accept protons
What makes a weak base a weak base?
Only a small proportion of the base molecules will accept protons
Name a weak base
Ionic equation for when an acid is added to water
HCl + aq ----------> H+ + Cl-
Ionic equation for the formation of water in a neutralisation reaction
H+ + OH- ----------> H2O
What is a salt?
Any chemical compound formed from an acid when a H+ ion from the acid has been replaced by a metal ion or another positive ion such as an ammonium ion
The three ways salts can be formed
Neutralising acids with carbonates, bases and alkalis
What happens when an acid is added to a carbonate?
Salt, water and carbon dioxide is produced
What happens when an acid is added to a base?
Salt and water
What happens when an acid is added to a alkali?
Salt and water
What is a titration?
An experiment in which an acid is added to a basic solution or the other way round until the reactants just neutralise each other
What are the 10 steps to a titration?
1) The burette is set up containing the standard solution
2) Initial volume is recorded
3) The accurate known volume of the other solution is added to a flask using a volumetric pipette
4) Small amount of indicator is added to the flask
5) A white tile is placed underneath the flask to ensure the colour change shows
6) The standard solution is slowly added to the flask
7) The flask is swirled gently to ensure mixing
8) Stop adding when indicator just changes permanently
9) Final volume recorded
10) Repeat until 2 titres are concordant within 0.1 cm3 of each other
Name 3 possible indicators for a titration
Outline the use of methyl orange
Red in acid
Yellow in base
Orange as the end point colour
Outline the use of bromothymol blue
Yellow in acid
Blue in base
Green as the end point colour
Outline the use of phenolphthalein
Colourless in acid
Pink in base
Pale pink as the end point colour