When working with multiple ground glass joints in a set-up, the time that you should apply grease to the joints is if the reaction is said to to be at a heated point that is above 150 oC, or, when the joints required is still rotated if in use.
Despite being made to fit together relatively nicely, ground glass joints are not completely airtight. In certain circumstances, grease must be applied to each joint to make sure of a good seal (such as when employing lower pressure inside an equipment).
Note that In ambient lighting, ground or frosted glass is frequently used as a heat- and weather-resistant light diffuser, particularly on the glass covers or enclosures for lamp fixtures and occasionally on incandescent bulbs.
Learn more about glass joints from
https://brainly.com/question/15190653
#SPJ1
