Ahmed is studying an unknown compound MP-110-1130C. He uses the flow chart below to identify the unknown compound. The concept used for this method is
Answers
EXPLANATION :
The possible unknown compound having melting point range 110-113⁰ C should be acetanilide.
In case of the given substance i.e, acetanilide, the melting point temperature range, MP-110-113⁰C. And MP of its pure sample is MP-113-115⁰C. We summarize that an impure solid, when over a mild range, melts and at a temperature lower than that of the pure solid. Hence, we can conclude that the given sample is impure.
⇒The concept used for identifying this compound is : CAPILLARY METHOD
METHODOLOGY -The capillary method is used as the standard technique for determination of melting point. In this method, a thin glass capillary tube is filled with the unknown substance. This tube which contains a compact column of the substance, is to be determined. This tube is then introduced into a heated stand (we can take a metal block or liquid bath for this) in close proximity to a high accuracy thermometer. The temperature within the heating stand is increased at a user programmable fixed rate until the sample present in the tube changes into the liquid state. A number of observations with different temperatures is being observed and recorded while determining a melting point.