acids and bases

• who made the Bronsted-Lowry theory?


  Johannes Bronsted and Thomas Lowry.
• what does the Bronsted-Lowry theory describe?

  the nature of acids and bases depending on whether they act as a proton donor or acceptor.
• what is a Bronsted-Lowry acid?

  a proton donor.
• what is a Bronsted-Lowry base?

  a proton acceptor.
• what do acid-base equilibria reactions involve?

  involve the transfer of protons where acids donate them and bases accept them.
• how can acids be described?


  as strong or weak, depending on the extent to which they can dissociate to donate protons when added to water.
• what will happen to a strong acid when added to water?

  will undergo complete dissociation when added to water and will donate all its available protons in an irreversible reaction. We show this by using a single headed arrow pointing from acid to the dissociated ions.
• what are 4 examples of a strong acid?

  hydrochloric acid, nitric acid, sulphuric acid and phosphoric acid.
• what is a monoprotic acid?

  acids that only donate one proton per mole of acid during dissociation.
• what are 2 examples of strong monoprotic acids?

  hydrochloric acid and nitric acid.
• what is a diprotic acid?

  an acid that produces 2 protons per mole of acid during dissociation.
• what is an example of a strong diprotic acid?

  sulphuric acid.
• what is the equation for hydrochloric acid during dissociation?

  HCL --> H+ + Cl-
• what is the equation for sulphuric acid during dissociation?

  H2SO4 --> 2H+ + SO2-4
• what is a triprotic acid?

  a strong acid that produced 3 protons per mole of acid during dissociation.
• what is an example of a triprotic acid?

  phosphorus acid.
• what is a weak acid?

  an acid that will only undergo partial dissociation when added to water.
• what is an example of a weak acid?

  all of the carboxylic acids. methanoic acid, ethanoic acid and propanoic acid.
• what do weak acids do during dissociation?

  weak acids only donate 1 proton per mole of acid in a reversible reaction where the acid and dissociation products are in equilibrium with one another. We show this with the equilibrium symbol.
• what are bases?


  they dissociate when added to water to produce positive ions and aqueous hydroxide ions (OH-). The presence of the hydroxide ions causes the solution to be alkaline in nature.
• how are Brønsted-Lowry bases described?

  as strong or weak depending on the extent to which they can dissociate to produce these OH- ions when added to water,
• what is a strong base?

  a strong base will completely dissociate in water to produce hydroxide ions and a positively charged metal ion.
• what are 3 examples of strong bases?

  sodium hydroxide, potassium hydroxide and lithium hydroxide.
• what are monobasic bases?


  bases that only produce 1 hydroxide ion per mole when they dissociate in water,
• what are 3 examples of strong monobasic bases?

  sodium hydroxide, potassium hydroxide and lithium hydroxide.
• what is the equation for NaOH dissociating?

  NaOG --> Na+ + OH-
• what are dibasic bases?

  bases that produce 2 hydroxide ions per mole when they dissociate in water.
• what are 2 examples of strong dibasic bases?

  calcium hydroxide and magnesium hydroxide.
• what is a tribasic base?

  a base that produces 3 hydroxide ions per mole when it dissociates in water.
• what is an example of a strong tribasic base?

  aluminium hydroxide.
• what is the equation for aluminium hydroxides dissociation?

  Al(OH)3 --> Al3+ + 3OH-
• what is a weak base?

  a base that only partially dissociates in a reversible reaction when added to water to produce hydroxide ions.
• what is an example of a weak base?

  ammonia.
• what happens when ammonia is added to water?

  it accepts a proton from the water to produce an ammonium ion and a hydroxide ion in a reversible reaction where the reactants and products are in a state of equilibrium.