Question

Did Döbereiner's triads also exist in the columns of Newlands' Octaves?
Compare and find out.
What were the limitations of Döbereiner's classification?
What were the limitations of Newlands' Law of Octaves?​

Answer 1

Answer:

Here i'm answering one by one

Hope it clears your doubt:-)

Kindly mark as brainliest

Explanation:

(a) Yes, Dobereiners triads also exist in the columns of Newlands' Octaves.

Consider the elements lithium (Li), sodium (Na) and potassium (K) which are present in the second column of Newlands' classification of elements. Now, if we start with lithium as the 1st  element, then the 8th element from it is sodium, and according to Newlands' law of octaves, the properties of 8th element, sodium should be similar to those of the 1st element, lithium.From this, we conclude that Dobereiners triads also exist in the columns of Newlands Octaves.

(b) The main limitation of Dobereiner's classification of elements was that it failed to arrange all the then known elements in the form of triads of elements having similar chemical properties. Dobereiner could identify only three triads from the elements known at that time. So, his classification of elements was not much successful. Another limitation was that Dobereiner failed to explain the relation between atomic masses of elements and their chemical properties.

(c) Newlands' law of octaves for the classification of elements had the following limitations:

(i) Newlands' law of octaves was applicable to the classification of elements up to calcium only. After calcium, every eighth element did not possess the properties similar to that of the first element. Thus, this law worked well with lighter elements only.

(ii) Newlands assumed that only 56 elements existed in nature and no more elements would be discovered in the future. But later on, several new elements were discovered whose properties did not fit into Newlands' law of octaves.