Chapter 2 terms part 2 Flashcards
Why is it seldom necessary to correct the masses of solids, in relation to buoyancy error?
Because the error caused by buoyancy is less than 0.1% for object that weighs 2 g/cm^3 and above
What are the other functions of weighing bottles aside from weighing substances?
For drying and storing liquids
What is the functions or purpose of a desiccator?
For drying substances or objects
How should one remove or replace the lid of a desiccator? And why should it be that way?
Using a sliding motion to minimize the likelihood of disturbing the sample
What type of liquids can be trasferred to previously weighed containers?
Those that are noncorrosive and relatively nonvolatile
What is the main function of simple crucibles?
These serve only as containers
What is usually the maximum temperature limit that the sintered-glass crucible can withstand?
200 degrees celsius
Which type of filtering media is suitable for filtering gelatinous precipitates?
Paper
What must a crucible be able to maintain when it will be used for weighing substances?
A constant mass (throughout drying or ignition)
When can mass be considered a constant one?
When consecutive weighing differ by 0.3 mg or less
How is backwashing done?
Turn the crucible upside down –> suck water through the inverted crucible
What are the steps in filtering an analytical precipitate?
Decantation, washing, and transfer
What is decantation?
Process of pouring a liquid while still securing the precipitate or solid in the bottom of the container
What is used to dislodge the remains of the precipitate inside the beaker after transferring the bulk of the precipitate?
Rubber policeman
What refers to the spreading of precipitates over a wetter surface against the force of gravity (or the process in which a solid moves up the side of a wetted container or filter paper?
Creeping
