If you can empty your glassware of chemicals before separating the joint, then safe ways of separating stuck joints include using a suitable solvent or lubricating oil to dissolve chemical residue in the joint, soaking the joints if required, and/or using a sonicator or ultrasonic cleaner.
How do you ensure a good seal at each glass joint?
Samples may evaporate through the joint over time, and if a highly volatile sample is used, the joint should be wrapped in Teflon tape (semi-stretchy white film or Parafilm (stretchy plastic film) to create a better seal.
When should you grease glass joints?
• GREASING GROUND GLASS JOINTS when the reaction is to be heated above 150 oC, or, if the joints needed to be rotated while in use. A short video on the application of grease to ground glass joints is available.
What is the purpose of greasing the glass tube joints during distillation?
In some situations (e.g. when using reduced pressure inside an apparatus), grease must be applied to each joint to ensure a good seal. Grease is also used whenever the joint may be in contact with a highly basic solution, as basic solutions can form sodium silicates and etch glass.
How do you open a glass joint?
Unsticking glass to glass joints and stopcocks If a freezer is not convenient, use a hair dryer or a similar type heat gun to gently heat the area. Again, wear gloves and gently twist apart. If you are fortunate enough to have a glassblower on site, let them dislodge the joint or stopcock.
How do you expand glass?
Why are glass joints ground?
Lack of lubrication between the two glass surfaces. If organic solvents come into contact with the joint, they can slowly dissolve the grease, leaving a dry glass-glass surface.
What is the purpose of using glassware with joints?
Types of Jointed Glassware The use of jointed glassware helps to avoid spills and leaks of potentially harmful and often valuable substances during experiments.
What do you put on a glass joint?
How do you grease a joint in chemistry?
What is a glass joint?
How do you separate fused glass?
How should you remove oil and grease from a ground glass joint?
You can de-grease ground glass joints by wiping them with a kimwipe soaked with hexane or acetone. Do this in the hood vent to prevent you from breathing in the chemicals. Do NOT dry glassware with a paper towel or forced air. This can introduce fibers or impurities.
How do you remove a glass bottle stopper?
- Apply a few drops of penetrating oil to the joint where the stopper and the glassware meet.
- Soak the glassware and stopper in hot water.
- Remove the item from the water.
- Remove the towel and gently tap around the bottle neck using a wooden spoon.
- Remove the stopper.
How do you open a glass decanter?
Wrap the decanter in a hot washcloth. Wet a washcloth in hot water and wrap it around the decanter’s neck. This can slightly expand the decanter to release the stopper. Wait five or ten minutes to allow the heat from the washcloth to transfer to the glass. Remove the washcloth and gently attempt to remove the stopper.
How do you make ground glass joints?
Does hot water make glass expand?
Once you pour boiling water into the glass, the inside part of the glass expands due to heat while the outer layer remains cool. The temperature difference will cause the inner layer to expand far greater than the outer part.
Does glass expand with heat?
anneal SOaK: 900°F (482°C) As glass heats, it expands; as it cools, it contracts. These processes set up stresses within glass, especially between the interior and the surface of a glass body.
How do you stretch holes in glass?
What is chemistry glass called?
Beakers are simple cylindrical shaped containers used to hold reagents or samples. Flasks are narrow-necked glass containers, typically conical or spherical, used in a laboratory to hold reagents or samples. Examples flasks include the Erlenmeyer flask, Florence flask, and Schlenk flask.
How do you measure a glass joint?
To find out if your joint is a 14mm all you need is a dime. If the dime is about the same size as your joint its a 14mm. If the dime falls into the joint its an 18mm, and if the joint is much smaller than a dime you have a 10mm joint. Another common joint size, 18mm joints are usually only found on the largest bongs.
How is ground glass made?
Ground glass is glass whose surface has been ground to produce a flat but rough (matte) finish, in which the glass is in small sharp fragments.
How are glass stoppers measured?
The number before the slash is the diameter of the large end of the ground area. This is the point that is gauged. The number after the slash is the length of the ground area in millimeters, measured parallel to the axis of the cone, that is, not by laying a ruler on the ground area.
What is frozen joint in glassware?
Most organic glassware uses “ground glass joints,” which have a frosted appearance. They are precisely ground to a certain size (which makes them expensive) and have outer (female) and inner (male) joints so that pieces can be connected together with a tight fit (Figure 1.1a).
What is the name of glassware No 14?
14 MATTE – Shtox.