How is Thiele tube used?
The Thiele tube is a glass tube designed to contain heating oil and a thermometer to which a capillary tube containing the sample is attached. The shape of the Thiele tube allows for formation of convection currents in the oil when it is heated.
Why Thiele tube is used in melting point?
Thiele-Dennis tubes are designed to give excellent convection and heat transfer for melting point and boiling point determinations. The unique design creates convection currents when the oil inside the tube is heated, allowing the oil to flow continuously through the tube without stirring or shaking.
Which oil is used in Thiele tube?
The paraffin oil is filled in the THIELE’S tube and it is used to know about the melting and boiling point. As it has high boiling point, thus it is used to maintain high temp.
How is melting point apparatus used?
A melting point apparatus is a laboratory device that is used to determine the melting point of an element with great precision and accuracy. The temperature at which the state of a substance changes from solid to liquid is said to be its melting point. Melting of a substance is generally obtained by heating it.
How do you use Mel temp?
Alternatively, drop the capillary tube down a length of glass tubing to pack the crystals into the bottom of the tube. When the crystals are packed into the bottom of the tube, place the tube into the slot behind the eyepiece on the Mel-Temp. Make sure the unit is plugged in and set to zero, then turn it on.
What is the melting point of an organic compound?
0.5 to 1.0⁰C
Crystalline organic compounds (Pure and Nonionic) have a very sharp and characteristic melting point of 0.5 to 1.0⁰C range. Even if there is a small amount of impurity in the mixture it would result in depression of the melting point and an increase in the melting point range.
Why is it necessary to determine the melting point of an organic compound?
What is the importance of knowing the melting point of organic compounds? The melting point is an important physical property of a compound. The melting point can be used to identify a substance and as an indication of its purity.
What will be effect if Thiele tube is heated vigorously?
Answer: The shape of the Thiele tube allows for the formation of convection currents in the oil when it is heated. These currents maintain a fairly uniform temperature distribution throughout the oil in the tube.
Which oils use melting point apparatus?
The unit consists of a built in magnetic stirrer, glare free background illuminator and cylindrical silicon oil bath. The silicon oil bath consists of a plain cylindrical container of corning glass having capacity of about 200 ml.
Which liquid is used in melting point apparatus?
A Thiele tube is a glass instrument that is filled with oil that is heated by using an open flame. The sample is placed in the opening in a capillary tube alongside a mercury thermometer and allowed to be heated by the oil as it circulates through the Thiele tube.
How do you use Mel temperature melting point apparatus?
Pack the capillary tube by pressing the open end gently into a sample of the compound to be analyzed. Crystals will stick in the open end of the tube. The solid should fill the tube to a depth of 2-3 mm. Tap the bottom of the capillary on a hard surface so that the crystals pack down into the bottom of the tube.
What is a Thiele tube?
Thiele tube. A photograph of a Thiele tube. The oil level is a little low now to compensate for expansion when heating commences. The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point of a substance.
How big is a Thiele thermometer?
The Thiele tube is made of glass and comes in different sizes, although a standard stocking is 150 mm long and has a volume of 40 ml. Apart from the tube, it brings with it a lid with two holes where the capillary tube and the thermometer are inserted.
Why is the oil level low in a Thiele tube?
The oil level is a little low now to compensate for expansion when heating commences. The Thiele tube, named after the German chemist Johannes Thiele, is a laboratory glassware designed to contain and heat an oil bath. Such a setup is commonly used in the determination of the melting point of a substance.
What happens when a sample is heated in Thiele tube?
The Thiele tube is heated; dissolved gases evolve from the sample first. Once the sample starts to boil, heating is stopped, and the temperature starts to fall. The temperature at which the liquid sample is sucked into the sealed capillary is the boiling point of the sample.