Ana Chem Midterms

Question 1

the analyte is
converted to a soluble precipitate.

Answer 1

Precipitation method

Question 2

the analyte or its
decomposition products are volatilized at a
suitable temperature

Answer 2

Volatilization method

Question 3

gravimetric precipitating agent
should react

Answer 3

Specifically

Question 4

Sumarry of steos in precipitation gravimetry

Answer 4

precipitation
Digestion
Filtration
Drying

Question 5

Precipitates made up of___ particles are
generally desirable in gravimetric work

Answer 5

Large

Question 6

solid made up of particles having
diameters that are less than 10-4 cm.

Answer 6

Colloid

Question 7

Coagulation can be hastened by ——,——,—-

Answer 7

Heating, stirring and ading electrilytes

Question 8

Larger particles can also be obtained by

Answer 8

Ph control

Question 9

is a process in which a substance (gas,
liquid, or solid) is held ON the surface of a solid

Answer 9

aDsorption

Question 10

Coagulation of a colloidal suspension can often be
brought about by

Answer 10

short period of heating and stirring

Question 11

is a process by which a coagulated
colloid returns to its dispersed state.

Answer 11

Peptization

Question 12

Colloids are best precipitated from hot, stirred
solutions containing sufficient electrolyte to
ensure coagulation

Answer 12

True

Question 13

four types of coprecipitation

Answer 13

Surface adsorption, mixed crystal formation, occlusion, and mechanical entrapmnt

Question 14

is a process in which normally
soluble compounds are carried out of solution
by a precipitate.

Answer 14

Coprecipitation

Question 15

common source of coprecipitation

Answer 15

Adsorption

Question 16

Minimizing Adsorbed Impurities on Colloids

Answer 16

Surface adsorption

Question 17

A drastic but effective way to minimize the effects of adsorption

Answer 17

Reprecipitation

Question 18

one of the ions in the
crystal lattice of a solid is replaced by an ion of
another element.

Answer 18

Mixed crystal formation

Question 19

is a type of coprecipitation in which a
compound is trapped within a pocket formed
during rapid crystal growth.

Answer 19

Occulusion

Question 20

is a process in
which a precipitate is formed by SLOW
generation of a precipitating reagent
homogeneously throughout a solution.

Answer 20

homogeneous precipitation

Question 21

New compound is often called ad

Answer 21

Weighing form

Question 22

Recording thermal decomposition curves
isoften called

Answer 22

Thermogravimetry

Question 23

includes a group of analytical
methods based on determining the quantity
of a reagent of known concentration that is
required to react completely with the analyte.

Answer 23

Titrimetry

Question 24

type of titrimetry in
which the standard reagent is measured
volumetrically

Answer 24

Volumetric titrimetry

Question 25

is a type of titrimetry in which the quantity of charge in coulombs required to complete a reaction with the analyte is measured

Answer 25

Coulometric titrimetry

Question 26

is a reagent of known concentration

Answer 26

Standard solution

Question 27

process in which a standard reagent is added to a solution of an analyte until the reaction between the analyte and reagent is judged to be complete

Answer 27

Titration

Question 28

is a process in which the excess of a standard solution used to consume an analyte is determined by titration with a second standard solution.

Answer 28

Back titration

Question 29

important observations are confined to a small region (typically ± 0.1 to ± 0.5 mL) surrounding the equivalence point.

Answer 29

Sigmoidal Curve

Question 30

measurements are made on both sides of but well away from the equivalence point. Measurements near equivalence are avoided.

Answer 30

Linear segment curve

Question 31

a reagent of known concentration that is used in a titrimetric analysis.

Answer 31

Standard Solution

Question 32

a process in which a standard reagent is added to a solution of an analyte until the reaction between the analyte and reagent is judged to be complete.

Answer 32

Titration

Question 33

the point in a titration when the amount of added standard reagent is equivalent to the amount of analyte.

Answer 33

Equivalence Titration

Question 34

the point in a titration when a physical change occurs that is associated with the condition of chemical equivalence.

Answer 34

End Point

Question 35

often added to the analyte solution to give an observable physical change (the end point) at or near the equivalence point

Answer 35

Indicator

Question 36

highly purified compound that serves as a reference material in all volumetric and mass titrimetric methods.

Answer 36

primary standard

Question 37

a compound whose purity has been established by chemical analysis and that serves as the reference material for a titrimetric method of analysis.

Answer 37

Secondary Standard

Question 38

Two basic methods are used to establish the concentration of such solutions.

Answer 38

Direct Method and Standardization