Question

how to prevent leakage of solid during vacuum filtration?

why we Do NOT use water to aid in the transfer of the precipitate from the vessel to the Buchner funnel in Preparation of Tetraammine copper(II)Sulfate monohydrate ? and Why do we wish to minimize the amount of water added?

Answer 1

Leakage can be prevented by using Whatmann No 40 or 41 or 42 for filteration. Because these filter papers do not allow solute particles, they allow only solvent particles.

Ordinary filter paper may allow solute particles to through it that causes to leakage of solid during filteration.

Tetramminedichlorocobalt(II) sulfate is soluble in water. If we use more amount of water then precipitate may be soluble in water then we lose some solid in solution. So we have to minimum amount of water to get precipitate.