the nature of analytical chem

Question 1

a measurement science consisting of set of powerful ideas and methods that are useful in all fields of science and medicine

Answer 1

analytical chemistry

Question 2

reveals the identity of elements and compounds in a sample

Answer 2

qualitative chemistry

Question 3

indicates the amount of each substance in a sample (analyte)

Answer 3

quantitative chemistry

Question 4

what are the different roles of analytical chemistry

Answer 4

chemistry
agricultural
medicine
physics
biology
engineering
geology
environmental science

Question 5

classifying quantitative analytical methods:
the results of typical quantitative analysis are computed from 2 measurements

Answer 5

mass or vol of sample to be analyzed
measurement of some quantity that is proportional to the amt. of analyte in the sample

Question 6

what are the nature of the final measurement of typical quantitative analytical method

Answer 6

gravimetric method
volumetric method
electroanalytical methods
spectroscopic methods

Question 7

this analytical method is costly and the speed is slow

Answer 7

gravimetry

Question 8

what needs to be considered in the selection process

Answer 8

level of accuracy period
no. of samples to be analyzed (economics)

Question 9

it involves obtaining a small mass of a material whose composition accurately represents the bulk of the material being sampled.

Answer 9

sampling

Question 10

the most difficult step in an analysis and the source of greatest error

Answer 10

sampling (aquire the sampling)

Question 11

a material is ______ if its constituent parts can be distinguished
visually or with the aid of a microscope

Answer 11

heterogeneous

Question 12

it is the process of determining how much of a given sample is the material by its indicated name

Answer 12

assay

Question 13

we analyze ______ and we determine ______

Answer 13

samples
substances

Question 14

the first step in processing the sample is often the….

Answer 14

preparation of a laboratory sample

Question 15

a _____ is ground, mixed to ensure _____, and stored for various
lengths of time before analysis begins

Answer 15

solid sample
homogeneity

Question 16

because any loss or gain of water changes the chemical composition of solids, it is a good idea to ____ just before starting an analysis

Answer 16

dry samples

Question 16

in preparing laboratory sample,
If the analyte is a gas dissolved in a liquid, analyte must be kept inside a ______

Answer 16

second sealed container

Question 17

if the analyte is a gas dissolved in a liquid, analyte must be kept inside a second sealed container. why

Answer 17

to prevent contamination by atmospheric gases

Question 18

it improves the quality of the results and provides a measure of
their reliability

Answer 18

replication

Question 19

species other than the analyte that affect the final measurement are called ____

Answer 19

interference

Question 20

analytical results are incomplete without an ______

Answer 20

estimate of their reliability

Question 21

the process of continuous measurement and control

Answer 21

feedback system

Question 22

the cycle of measurement, comparison, and control is called a

Answer 22

feedback loop