CHAP 35

Question 1

is resistant
to heat and attack by strong chemical
agents.

Answer 1

refractory substance

Question 2

SOURCES OF ERROR IN DECOMPOSITION
AND DISSOLUTION

Answer 2

1. Incomplete Dissolution of the analytes
2. Losses of analyte by volatilization
3. Introduction of analyte as a solvent contaminant
4. Introduction of contaminants from reaction of the solvent with vessel walls

Question 3

INORGANIC
ACIDS USED FOR DECOMPOSING SAMPLES IN OPEN VESSELS

Answer 3

Hydrochloric acid
Nitric acid
Sulfuric Acid
Perchloric Acid
Hydrofluoric acid
Oxidizing Mixtures such as aqua regia

Question 4

a mixture
containing three volumes of concentrated hydrochloric acid and one volume of
nitric acid

Answer 4

aqua regia

Question 5

is a process of oxidative
decomposition of organic samples
by liquid oxidizing reagents, such as
HNO3, H2SO4, HClO4, or mixtures
of these acids.

Answer 5

wet ashing

Question 6

MICROWAVE DECOMPOSITIONS

Question 7

COMBUSTION METHODS FOR DECOMPOSING
ORGANIC SAMPLEs

Answer 7

1. Combustion over an Open Flame (Dry Ashing)
2. Combustion-Tube Methods
3. Combustion with Oxygen in a Sealed Container

Question 8

the thermochemical
decomposition of organic compounds
at elevated temperature in the absence
of oxygen

Answer 8

pyrolysis

Question 9

the process
in the presence of oxygen.

Answer 9

Combustion

Question 10

dry ashing

Answer 10

a process of oxidizing an
organic sample with oxygen or air at
high temperature, leaving the
inorganic component for analysis.

Question 11

types of fluxes

Answer 11

1. sodium carbonate
2. potassium pyrosulfate
3. lithium metaborate

Question 12

_________ is alkali metal salt
_________ the water soluble product formed

Answer 12

flux; melt

Question 13

common types of fluxes

Answer 13

1. Alkali metal carbonates, hydroxides, peroxides, and borates are basic fluxes used
   to attack acidic materials.
2. The acidic fluxes are pyrosulfates, acid fluorides, and boric oxide.
3. If an oxidizing flux is required, sodium peroxide can be used