Limitations of Dobereiner’s Classification

What were the Limitations of Dobereiner’s Classification?

Chemical families were discovered in 1829 by Johann Wolfgang Dobereiner. Compared to Li and K, Na’s atomic weight is very close to the average. The triad’s components are very similar in their properties.

Some elements with similar chemical properties could be grouped, according to Dobereiner Groups of three are the most common arrangement for these elements when arranged according to increasing atomic mass. Triads were the name given to these groups. In the triad, the atomic mass of the middle element was the arithmetic mean of the atomic masses of the other two elements.

Let’s Use an Example to Help Us Better Understand!

Alkali metals are a family of elements that include lithium (Li), sodium (Na), and potassium (K), amongst others (K). Because they are all metals, their reactivity is particularly high. The atomic mass of the element in the middle, sodium, in this case, should be calculated by taking the arithmetic mean of the masses of lithium and potassium.

Let Us Now Examine Dobereiner’s Classifications’ Limitations

• There is no way to categorise all known elements into groups of triads by using the properties of those elements.
• Some groups did not adhere to the Law of Triads. The Nitrogen family, for instance, deviates from the Triad Law in their behaviour.
• Doberiner was only able to identify a total of three different triads. Because of this, he could not construct triads using all of the elements that he was familiar with.
• The rule did not apply to substances with either an extremely low mass or an extremely high mass. Use the letters F, Cl, and Br.