4.2 strength of acids and bases

examples of strong and weak acids

strong: hcl, h2so4, hno3
weak: ch3cooh, h2co3, h3po4

examples of strong and weak bases

strong: naoh, Koh, ca(oh)2
weak: nh3

define a strong acid

acids that readily donate a proton

define a weak acid

acids that partially ionise to donate a proton, can readily reverse reaction

differentiate between strong and weak acid

strong acids are a forward direction reaction, acid will readily donate a proton and will have no unreacted particles remaining.

weak acids are a reversible reaction and exist at equilibrium, acid only partially ionises and majority of the product will not exist in a proton form.

define a strong base

bases that accept protons easily

define a weak base

ionises in water to accept a proton, but does not completely ionise, therefore only a small proportion exists as an OH- molecule, can be reversed.

if an acid is strong what about the conjugate base?

the stronger the acid the weaker the conjugate base

if a base is strong what about its conjugate acid?

the stronger the base the weaker the conjugate acid

how can the strength of an acid or a base be described?

described int erms of the position of the equilibrium earn the substance either donates or accepts a proton from water. (hydrolysis reaction).

how can you tell the strength of an acid with its eq constant?

large Ka value = strong (fully ionised).

small Ka value = weak (partial)

how can you tell the strength of a base with its eq constant?

large Kb value = strong base high extent of dissociation

small Kb value = weak base low (partial)