topic 6: pH scale & acidity n basicity

what is the pH scale?

the pH is a scale that measures the H+ conc of a solution

what can pH be measured with?

pH meter

pH paper

acid-base indicators

what is the formula for pH?

pH = -log[H+]

what happens when [H+} increases?

as [H+} increases in a solution, pH decreases, more acidic

what is the formula for pOH?

pOH = - log [OH-]

what happens when [OH-] increases?

as [OH-] increases in a solution, pOH decreases, more basic

what do pH and pOH do?

pH and pOH measure the acidity and basicity of a solution respectively

what happens when pH increases?

as pH increases, solution becomes more basic, pOH must decrease

what happens when pH decreases?

as pH decreases, solution becomes more acidic, pOH must increase

what is the sum of pH and pOH?

14

what is a conjugate acid?

a base accept H+ and the resulting molecule/ion is its conjugate acid

what is a conjugate base?

an acid donates H+ and the resulting molecule/ion is its conjugate base

what happens when the acid is strong?

the stronger the acid, the weaker the conjugate base

what happens when the base is strong?

the stronger the base, the weaker the conjugate acid

how can the pH of a salt solution be predicted?

the pH of a salt solution can be predicted using the cation and anion of the salt

what should be considered when predicting the pH of salt solutions

consider the relative strengths of the relevant acid and base

what are some examples of a strong cation & strong acid neutral solution?

NaCl

KBr

NaNO3

what are some examples of strong cation & weak anion from a basic salt solution?

Na2CO3

KCH3CCOO

what are some examples of a weak cation & strong anion from a acidic salt solution?

NH4Cl

NH4NO3

what are some examples of a weak cation & weak anion of a salt solution?

NH4CN

FeCO3