स्टॉपकॉक इसके अंग्रेजी अर्थ का उदाहरण

Although the acid is free to flow down through the tube into the bottom chamber, it is prevented from rising there by the pressure of the gas contained above it, which is able to leave the apparatus only by a stopcock near the top of the middle chamber.

This stopcock may be opened, initially to permit the air to leave the apparatus, allowing the liquid in the bottom chamber to rise through the retention plate into the middle chamber and react with the solid material.

Gas is evolved from this reaction, which may be drawn off through the stopcock as desired.

When the stopcock is closed, the pressure of the evolved gas in the middle chamber rises and pushes the acid back down into the bottom chamber, until it is not in contact with the solid material anymore.

At that point the chemical reaction comes to a stop, until the stopcock is opened again and more gas is drawn off.

The Dean–Stark apparatus typically consists of a vertical cylindrical glass tube, often with a volumetric graduation along its full length and a precision stopcock at its lower end, very much like a burette.

They are fitted with a stopcock which allows the flow to be controlled.