what will be the result of error in distillation resulting from placing thermometer in a boiling liquid?

Answer 1

the temprature recorded by putting the thermometer inside the liquid is not the actual boiling temprature because the liquid might be impure. The temprature recorded of the vapour above the liquid which is pure is the actual boiling temprature of the liquid.

Answer 2

"Boiling Point" is usually defined at a pressure exactly 1 atmosphere, or 760 mm mercury pressure.

If you do your experiment anywhere above sea level, the pressure will be lower than 760 mm mercury, so the boiling temperature you measure will be too low.

If you really want the boiling point of a pure substance, then I agree that you should set up a distillation appratus and put the thermometer in the condensing liquid, not in the distillation pot. But if you really want the boiling point of the impure liquid, then the thermometer should be in the pot.

You need to adjust the pressure to exactly 760 mm mercury, or else take measurements at a series of lower pressures, plot them on a chart of temperature vs pressure, and extrapolate the curve to read off the temperature value at 760 mm mercury.

Answer 3

The thermometer placed in the way of vapor of a boiling liquid to be distilled , in order to get pure substance according to the boiling point of it, if we are placing the thermometer in the boiling liquid we measured the temp.of the mixture not of the desire substance we need to distill it .

Answer 4

well i think if the thermometer wasnt contaminated with a different solution than what was in the boiling liquid then there wouldnt be any error.. However if it was contaminated then it is possible your distillate will be contaminated. i also agree with the person before.