Question

Which of these compounds are soluble in water (or react with it)?

a)Chromium(III) oxide
b)Arsenic trichloride
c)Lead(II) nitrate
d)Molybdenum disulfide
e)Mercury iodide
f)Sodium metavanadate

Answer 1

Well, `(b)`, and `(c)`, and `(f)` to a first approx...

Explanation:

Chromic oxide, and `MoS_2`, and `HgI_2` are all as soluble as bricks in aqueous phases. On the other hand, `AsCl_3`, the old so-called `"butter of arsenic"`, would swiftly react with water according to the following equation..

`AsCl_3(l) + 3H_2O(l) rarr As(OH)_3(aq) + 3HCl(aq)`

`Pb(NO_3)_2` speciates in aqueous solution to give stoichiometric `Pb^(2+)` and `NO_3^(-)`. Note that MOST nitrate salts are water soluble...given that the anion is not very charge dense.

Sodium metavanadate, `Na^+VO_3^(-)` would have some considerable water solubility. Did I get them all?