cobalt pigment

Testing dissolution of "oxide" (black ppts) with NaOH solution (H1). Merged black powders (MC20)+(ME9)+(MC18)+(ME108) into a large test tube (ME140).

Squeezed liquid off the chopped filter papers (ME1pq) (clear very light pink) into acidic residue flask (MF0).  Washed the paper bits with lots of water.  Filtering the wash-off as filtration ((1)):

* (ME150) liq, clear white, very sly pink.

* (ME151) ppt, black.

The filter papers (ME1pq) still had some black ppt impregnating them.  Put in a beaker (ME154).

Squeezed liquid from filter paper bits in (MEF5) and (ME101) (ppt from blue liquor treated with ethanol, filtered out and steeped in HAc).  Filtering:

* (ME152) liq, clear very sly pink.

* (ME153) ppt black.  Washed with ~2 mL H2O, with wash merged into (ME152).


Squeezed the liquid off the filter paper bits in (ME93) into filtration ((1)), that is, (ME150) and (ME151).  Washed the filter paper bits in (MEF5), (ME101) and (ME93) with lots of H2O.  Dumper the washout in the filter of filtration ((1)).  Added the filter paper bits, still with some black impregnation, to beaker (ME154).


Added ~100 mL of (ME107)+(ME132) to the dirty paper bits in (ME154).  Heated.  Added 1 tsp of NaOH.  No obvious blue color.

Washed the black ppt (ME153) off the filter paper into filtration ((1)), that is, (ME150) and (ME151).

Filtering (ME1pr):

* (ME1ps): liq, clear salmon pink.  (Contains iron?)

* (ME1pt): ppt, brown (Contains iron?)

The filter paper bits in (ME1pr) were now almost clean; discarded.

Added 8 mL Na2CO3 sol (sat 16 C) to (ME152). After bubbling stopped, lilac ppt formed.

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