The sample for which melting point is being measured is not a pure sample.
It is observed that if a compound shows a lower temperature than the predicted melting point temperature / melting point range it is due to presence of impurity in the sample.
The presence of impurities decreases the melting point of any substance.
Answer:
The sample is not pure. It has small impurities in it.
Explanation:
When the substance are pure, they have
In the above case, the known sample has M.P 134-137 centigrade, while recorded sample has M.P 125-126 degrees Celsius that's shows lowering of M.P is due to small amount of impurities.
Reason:
I.M.F become weak when impurities are present which consequently causes the lowering of M.P
