6 a Write down the name and formula of the black substance that forms in the experiment above.
b Suggest a way to turn it back into copper.
(pg 92 )

Possible lowest volume = 0.19 cm

Possible highest volume = 0.21 cm

Explanation:

given data

volumetric pipette uncertainty  =  0.01 cm³

total volume = 0.20 cm³

solution

we will get here Possible lowest and highest volume that is express as

Possible lowest volume = total volume - uncertainty   1

Possible highest volume = total volume + uncertainty    2

put here value in both equation and we get

Possible lowest volume = 0.20 cm - 0.01 cm

Possible lowest volume = 0.19 cm

and

Possible highest volume = 0.20 cm + 0.01 cm

Possible highest volume = 0.21 cm