Wet chemistry

Source: Wikipedia, the free encyclopedia.
Graduated cylinders and beakers filled with chemicals

Wet chemistry is a form of analytical chemistry that uses classical methods such as observation to analyze materials. The term wet chemistry is used as most analytical work is done in the liquid phase.[1] Wet chemistry is also known as bench chemistry, since many tests are performed at lab benches.[2]

Materials

Wet chemistry commonly uses

laboratories teach students basic wet chemistry methods.[8]

History

Before the age of

automated and computerized for streamlined analysis. The manual performance of wet chemistry mostly occurs in schools.[citation needed
]

Methods

Qualitative methods

Qualitative methods use changes in information that cannot be quantified to detect a change. This can include a change in color, smell, texture, etc.[9][10]

Chemical tests

When burned, lead produces a bright white flame.

Chemical tests use reagents to indicate the presence of a specific chemical in an unknown solution. The reagents cause a unique reaction to occur based on the chemical it reacts with, allowing one to know what chemical is in the solution. An example is Heller's test where a test tube containing proteins has strong acids added to it. A cloudy ring forms where the substances meet, indicating the acids are denaturing the proteins. The cloud is a sign that proteins are present in a liquid. The method is used to detect proteins in a person's urine.[11]

Flame test

The flame test is a more well known version of the chemical test. It is only used on metallic ions. The metal powder is burned, causing an emission of colors based on what metal was burned. For example, calcium (Ca) will burn orange and copper (Cu) will burn blue. Their color emissions are used to produce bright colors in fireworks.[citation needed]

Quantitative methods

Quantitative methods use information that can be measured and quantified to indicate a change. This can include changes in volume, concentration, weight, etc.

Gravimetric analysis

Solids are filtered out of the liquid, which is collected in the beaker.

Gravimetric analysis measures the weight or concentration of a solid that has either formed from a precipitate or dissolved in a liquid. The mass of the liquid is recorded before undergoing the reaction. For the precipitate, a reagent is added until the precipitate stops forming. The precipitate is then dried and weighed to determine the chemicals concentration in the liquid. For a dissolved substance, the liquid can be filtered until the solids are removed or boiled until all the liquid evaporates. The solids are left alone until completely dried and then weighed to determine its concentration. Evaporating all the liquid is the more common approach.[citation needed]

Volumetric analysis

Volumetric analysis or

endpoint. Since the color change can occur very suddenly, it is important to be extremely precise with all measurements.[citation needed
]

Colorimetry

Colorimetry is a unique method since it has both qualitative and quantitative properties. Its qualitative analysis involves recording color changes to indicate a change has occurred. This can be a change in shading of the color or a change into a completely different color. The quantitative aspect involves sensory equipment that can measure the wavelength of colors. Changes in wavelengths can be precisely measured and indicate changes in the mixture or solution.[citation needed]

Uses

Wet chemistry techniques can be used for

titrimetry. Some uses for wet chemistry include tests for:[citation needed
]

Wet chemistry is also used in environmental chemistry settings to determine the current state of the environment. It is used to test:[citation needed]

  • Biochemical Oxygen Demand (BOD)
  • Chemical Oxygen Demand (COD)
  • eutrophication
  • coating identification

It can also involve the elemental analysis of samples, e.g., water sources, for chemicals such as:[citation needed]

See also

  • Wet laboratory

Further reading

  • Elizabeth K. Wilson. "Phoenix Tastes Water Ice On Mars".
    C&EN
    .
  • Beck, Charles M. II. (February 15, 1994). "Classical Analysis: A Look at the Past, Present, and Future".
    S2CID 242506938
    .

References

  1. PMID 22221657
    .
  2. PMID 33501193
    .
  3. PMID 3134332 – via PubChem
    .
  4. PMID 25366403
    .
  5. S2CID 26111444
    .
  6. S2CID 52915349
    .
  7. S2CID 45997408
    .
  8. PMID 17146040
    .
  9. PMID 27744149
    .
  10. PMID 30763498
    .
  11. ISBN 978-0-19-955715-8
    .
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