What are the source of error in determination of boiling point and melting point

Experimental error is the source of error in determination of boiling point and melting point.

Errors in the boiling and melting point measurement occurs due to experimental errors such as heating the water bath too rapidly, poor alignment of the thermometer and sample.

These errors can leads to providing false data about the boiling and melting point of a substance so we can conclude that experimental error is the source of error in determination of boiling point and melting point.

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the atomic mass is the bottom number on the element.

-steel jelly

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.