The two compounds are mixed together in a reaction vessel to produce a prepolymer.

The process of reactive distillation involves using the reaction vessel as the still.

The reaction vessel is then partially covered by sand or pellets.

The sand or shot then conducts the heat from the plate to all sides of the reaction vessel.

In the centre, towards the back, are the reaction vessels, where the chemical reactions take place.

The building is also more open plan than older buildings with much more space between the respective reaction vessels.

The claim does not say anything about a reaction vessel or even temperature measuring devices.

Laboratory tests show that under the conditions in the reaction vessel, a 90% yield is obtained after 2 hours.

The equilibrium is based on the ratio of concentrations for each component in the reaction vessel.

Your reaction vessel will begin by containing air, I would guess, which has its own weight making the flask weigh more.