Question

why does the temperature in thermometer not rise till aceton is changed into vapours

Answer 1

Because the heat provided at boiling point in liquid state is used for breaking of bonds and conversion of state that is why temperature in thermometer doesn't rise till acetone is changed into vapours. 

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MARK AS BRAINLIEST

Answer 2

As the heat(energy) we provided to acetone is used for breaking of bonds and to convert its state of matter