One compound contains only
C, H, O and Cu.
In the analysis for
`Cu^(2+),a0.115` g sample of
the compound is reacted with
concentrated mitric acid,
evaporated to dryness and the
residue is dissolved in `H_(2)O.` In
the resulting solution the `Cu^(2+)`
is reacted with excess `I^(-)` and
the resulting lodine is titrated
with 0.0320 M `S_(2)O_(3)^(2-)` ,
requiring 11.75 mL.
The combustion of a 0.250 g
sample of the compound
produces 0.504 g of `CO_(2)` and
0.0743 g of `H_(2)O`
What is the number of oxygen
atoms per copper atom ? (At. Mass of Cu=63.5 g `"mol"^(-1)` )

Explanation

4