Gravimetric Analysis

Question 1

the analyte is separated from a
solution of the sample as a
precipitate and is converted to a
compound of known composition
that can be weighed.

Answer 1

Precipitation gravimetry

Question 2

the analyte is separated from
other constituents of a sample by
conversion to a gas The weight of
this gas then serves as a measure
of the analyte concentration

Answer 2

Volatilization gravimetry

Question 3

In volatization gravimetry, the sample is converted to what?

Answer 3

Gas

Question 4

What serves as a measure of the analyte concentration in volatization gravimetry?

Answer 4

Weight of escaped gas

Question 5

the analyte is separated by deposition on an
electrode by an electrical current

Answer 5

Electrogravimetry

Question 6

an electric conductor that makes contact with the nonmetallic circuit parts of a circuit, such as an electrolyte, semiconductor, or vacuum

Answer 6

Electrode

Question 7

Method of thermal analysis in which changes in
physical and chemical properties of materials are measured as a function of increasing temperature or as a function of time.

Answer 7

Thermogravimetry

Question 8

refers to process in solution with excess amount of solute

Answer 8

Supersaturation

Question 9

a substance that causes the precipitation of a specified substance.

Answer 9

Precipitant

Question 10

Whose tiny particles are invisible to the
naked eye (10-7 to 10-4 cm in diameter)

Answer 10

Colloidal particle

Question 11

Particles visible to the naked eye

Answer 11

Crytalline solid

Question 12

Which particle settles down spontaneously

Answer 12

Crystalline solid

Question 13

Known as the Oswald Ripening

Answer 13

Digestion of precipitate

Question 14

involves dissolution of small particles
and reprecipitation on larger ones resulting in
particle growth and better precipitate
characteristics.

Answer 14

Digestion

Question 15

process by which a coagulated colloid reverts to
its original dispersed state in case of colloidal
precipitates

Answer 15

Peptization

Question 16

In this, the precipitate is
converted to a more chemically stable form

Answer 16

Drying and ignition

Question 17

The ideal precipitating reagent would react
__________ or at least ___________

Answer 17

Specifically, selectively

Question 18

Which type of precipitate is ideal?

Answer 18

Crystalline

Question 19

T or F: ideal precipitate are of sufficiently low solubilty

Answer 19

True (so it doesnt dissolve and it can be filtered)

Question 20

an unstable solution that contains a higher solute concentration than a saturated solution.

Answer 20

Supersaturated solution

Question 21

In relation to Ksp and Qsp, when can precipitation happen

Answer 21

Ksp > Qsp

Question 22

Relation of precipitation and supersaturation

Answer 22

Inversely proportional (kapag mataas ang supersaturation ibig sabihin marami ang solute. these solute can be formed into precipitate and when they do, bumababa ang saturation. gets???)

Question 23

a process of forming smaller particles or colloidal particles.

Answer 23

Nucleation

Question 24

The initial formation process in which
a minimum number of atoms, ions, or molecules join
together to give a stable solid.

Answer 24

Nucleation

Question 25

The subsequent growth after nucleation; building up of formerly formed nuclei

Answer 25

Particle growth

Question 26

Two ways to control RSS and increase particle growth

Answer 26

* Increase equilibrium solubility * Decrease solute concentration

Question 27

says that particles collide but do not interact. It is not affected by gravity

Answer 27

Brownian movement

Question 28

Which type of precipitate is Brownian Movement applied?

Answer 28

Colloids

Question 29

Refers to accumulation and build up

Answer 29

Coagulation

Question 30

Involves a combination of larger group of many different ions/atoms with each other

Answer 30

Agglomeration

Question 31

Which particles are stable?

Answer 31

Colloids

Question 32

Why are colloids stable?

Answer 32

It has negative and positive chargue

Question 33

Refers to the mainly absorbed ions on the surface

Answer 33

Primary adsorption level

Question 34

Contains sufficient excess of negative ions to balance the charge on the primary adsorption layer

Answer 34

Counter-ion layer

Question 35

This layer prevents interaction with the same kind of particle due to the presence of the negative ions found within this layer.

Answer 35

Counter-ion layer

Question 36

thought as a measure of the repulsive force that the particle exerts on like particles in the solution.

Answer 36

Effective charge

Question 37

Diameter of colloids

Answer 37

10^-7 to 10^-4 cm

Question 38

Characteristics of colloids

Answer 38

Suspended

Question 39

Characteristics of crystalline

Answer 39

Settled from the solution (filterable)

Question 40

Diameter of crystalline partices

Answer 40

>10^-4 cm

Question 41

Relationship of nucleation, RSS, and particle size

Answer 41

High RSS = High nucleation = Small particles

Question 42

Relationship of particle growth, RSS, and particle size

Answer 42

Small RSS = High particle growth = Large particles

Question 43

Relationship between equilibrium solubility and RSS

Answer 43

High RSS, low solubility (they can't be soluble because it's supersaturated na) Therefore, to lower RSS is to increase solubility

Question 44

Relationship between RSS and concentration

Answer 44

High RSS, high concentration (concentration of solute is high because it's supersaturated) Therefore, to lower RSS is to decrease the concentration

Question 45

These are precipitants that creates complex ions.

Answer 45

Complexing agents

Question 46

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

Answer 46

Adsorption

Question 47

A process in which a substance within the pores of a solid.

Answer 47

Absorption

Question 48

generally more easily filtered and purified than coagulated colloids.

Answer 48

Crystalline

Question 49

improves the purity and filterability of both colloidal and crystalline precipitates. It makes the precipitate pure as impurities and contaminants are removed when filtered.

Answer 49

Digestion

Question 50

a process in which normally soluble compounds are carried out of solution by a precipitate and may result in impurities and/or contamination

Answer 50

Coprecipitation

Question 51

a process by which a foreign compound precipitates on top of the desired precipitate.

Answer 51

Post precipitation

Question 52

The impurity is chemically or physically adsorbed onto the surface of precipitates

Answer 52

Surface adsorption

Question 53

the major source of contamination in coagulated colloids but of no significance in crystalline precipitates.

Answer 53

Adsorption

Question 54

A type of coprecipitation in which a contaminant ion replaces an ion in the lattice of a crystal.

Answer 54

Mixed crystal formation

Question 55

type of coprecipitation in which a compound (foreign ions in the counter-ion layer) is physically trapped within a precipitate during rapid precipitate formation.

Answer 55

Occlusion

Question 56

T or F: Occlusion involve particles of same charge while Mixed Crystal formation doesnt

Answer 56

False (baliktad)

Question 57

A type of coprecipitation in which coprecipitated physically trap a pocket of solution within a precipitate during rapid precipitate formation.

Answer 57

Mechanical entrapment

Question 58

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

Answer 58

Homogenous precipitation

Question 59

done by adding an agent. A chemical added to a mixture which will block any impurity from affecting the chemical analysis

Answer 59

Masking