Why does it to keep the distillation head warm?

Distillation is the process of extracting all of the substances from a liquid solution by condensation or evaporation. The device used in this process of distillation is called distillation head. The liquid is heated and components with different boiling points are forced into the gas phase.The distillation head should be kept warm in order this process to last long time enough.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

Acovalent bond is formed between the two hydrogen bonds