Chapter 1 The Nature Of Analytical Chemistry

Question 1

What is Qualitative analysis?

Answer 1

Analysis reveals the identity of the element and compounds in a sample.

Question 2

What is Quantitative analysis?

Answer 2

Analysis indicates the amount of each substance in a sample.

Question 3

What are four quantitative analysis methods?

Answer 3

1. Gravimetric method (measures the mass)
2. Volumetric method (measures the volume)
3. Electroanalytical method (measures electrical properties)
4. Spectroscopic method (interaction between electromagnetic radiation and analyte atoms/molecules)

Question 4

List the steps for quantitative analysis.

Answer 4

1st step. Select method (level of accuracy, time and money)
2nd step. Acquiring the sample
3rd step.Processing sample
4th step. Eliminating interference
5th step. Calibration and measuring concentration
6th step. Calculating results
7th step. Evaluating results by estimating reliability

Question 5

What does heterogeneous material mean?

Answer 5

A material is heterogeneous (and large) if its constituent parts can be distinguished visually or with the aid of a microscope. Coal, animal tissue, and soil are heterogeneous.

Question 6

What is assay?

Answer 6

An assay is a process of determining how much of a given sample is the material by its indicated name. For example, a zinc alloy is assayed for its zinc content, and its assay is a particular numeric value.

Question 7

What is the process of sampling?

Answer 7

Sampling is the process of collecting a small mass of a material whose composition accuracy represents the bulk of the material being sampled.

Question 8

What do replicate samples, or replicates mean?

Answer 8

There are portions of the material of approximately the same size that are carried through an analytical procedure at the same time and in the same way.

Question 9

What does interface mean?

Answer 9

Is a species that causes an error in an analysis by enhancing or attenuating (making smaller) the quantity being measured.

Question 10

What is a sample matrix? ( or matrix)

Answer 10

Is the collection of all of the components in the sample containing an analyte.

Question 11

What is calibration?

Answer 11

is the process of determining the proportionality between the analyte concentration and a measured quantity.