Chapter 12: Principles of Neutralization Titrations Flashcards
is a weak organic acid or a weak organic base whose undissociated form differs in color from its conjugate base or its conjugate acid form.
acid-base indicator
2 types of titration error
determinate error
indeterminate error
occurs when the pH at which the indicator changes color differs from the pH at the equivalence point
determinate error
originates from the limited ability of the human eye to distinguish reproducibly the intermediate color of the indicator
indeterminate error
TRUE or FALSE
On average, the visual uncertainty with an acid-base indicator is in the range of 60.5 to 61 pH unit. This uncertainty can often be decreased to as little as 60.1 pH unit by matching the color of the solution being titrated with that of a reference standard containing a similar amount of indicator at the appropriate pH
TRUE
variables that influence the behaviour of indicators
temperature
ionic strength of the medium
presence of organic solents
colloidal particles
what acid-base indicators changes its color from red to yellow
thymol blue
methyl yellow
methyl red
what acid-base indicators changes its color from yellow to blue
thymol blue
bromocresol green
bromothymol blue
what acid-base indicators changes its color from red to orange
methyl orange
what acid-base indicators changes its color from yellow to pink
bromocresol purple
cresol purple
what acid-base indicators changes its color from yellow to red
phenol red
what acid-base indicators changes its color from colorless to red
phenolphthalein
what acid-base indicators changes its color from colorless to blue
thymolphthalein
what acid-base indicators changes its color from colorless to yellow
alizarin yellow GG
The standard solutions used in neutralization titrations are _____________ because these substances react more completely with an analyte than do weak acids and bases, and as a result, they produce sharper end points
strong acids or strong bases
TRUE or FALSE
Hot concentrated perchloric and sulfuric acids are potent oxidizing agents and are very hazardous
TRUE