Intro

What Is Analytical Chemistry?

Analytical Chemistry - Qualitative analysisAnalytical chemistry focuses on determining the composition of solutions and compounds through various methods of analysis. There are three major methods used:

  • Qualitative
  • Quantitative
  • Instrumental

Each of these groups have their own tests they use to identify compounds or atoms present at different measurements of accuracy. Two other key concepts involved in analytical chemistry are error and standards. Error is a factor in every chemistry experiment conducted. Because of this, it is vital to know what common causes of error are and how to calculate them. Standards are essential to know because these are what you compare your samples to and help determine error or purity of each sample.

Qualitative analysis is a simple method of testing to determine the presence, or lack of, in a sample. No quantities are determined through this method. Some examples of qualitative analysis are the Baeyer and Flame Tests.

The Baeyer Test is a method to determine the presence of a carbon to carbon double or triple bond in an organic molecule. A purple potassium permanganate solution (also known as the Baeyer Reagent) is added to the sample. If there is a carbon to carbon double or triple bond, the permanganate will undergo a reduction-oxidation reaction producing manganese (IV) oxide, which is a brown color.

The Flame Test helps determine the presence of a metal within the sample being tested. The compound is placed in a flame that causes the outer electron(s) to be excited. Due to the difference in energy to excite, elements emit various colors. Some examples are: lithium emitting a blood red color; copper emitting a green to blue depending on its oxidation state; and potassium having a light purple color.