Acids, Bases and pH Flashcards
What is the Brønsted-Lowry theory?
A theory that describes acid-base interactions in terms of proton transfer between chemical species
What are Brønsted-Lowry acids?
Proton donors
Why are Brønsted-Lowry acids called proton donors?
They release hydrogen ions when they’re mixed with water
Write the general equation for a general Brønsted-Lowry acid (HA) mixed with water
HA(aq) + H2O(l) ⇌ H3O+(aq) + A-(aq)
What are Brønsted-Lowry bases?
Proton acceptors
Why are Brønsted-Lowry bases called proton acceptors?
When they’re in a solution, they grab hydrogen ions from water molecules
Write the general equation for a general Brønsted-Lowry base (B) in a solution
B(aq) + H2O(l) ⇌ BH+(aq) + OH-(aq)
What do acids and bases do in water?
Break up into positive and negative ions (called dissociation)
What do strong acids do in water?
They dissociate almost completely in water - nearly all H+ ions are released
What do strong bases do in water?
They dissociate almost completely in water
What do weak acids do in water?
They dissociate only partially - so only a small amount of H+ ions are formed
What do weak bases do in water?
They only slightly dissociate
Describe the equilibrium position in the reversible reaction when a strong acid mixes with a water
The equilibrium lies far to the right, which is why nearly all the H+ ions are released
Describe the equilibrium position in the reversible reaction when a weak acid mixes with a water
The equilibrium lies far to the left, which is why only a small amount of the H+ ions are released
What are monobasic acids?
An acid that releases one H+ ion per molecule
What are monobasic acids also called?
Monoprotic acids (because an H+ ion is just a proton)
Give 2 examples of monobasic acids
HCl
HNO3
What are dibasic acids?
An acid that releases two H+ ion per molecule
Give an example of dibasic acids
H2SO4
What are tribasic acids?
An acid that releases three H+ ions per molecule
Give an example of a tribasic acid
H3PO4
What are tribasic and dibasic acids examples of?
Polyprotic acids
What is a species?
A type of chemical - could be a molecule, atom or an ion
What are conjugate pairs?
Species that are linked by the transfer of a proton (H+ ion)