Question

Zena, warrior princess, had a rock with `HgO` in it. If she had 60 grams of Mercury after heating the rock, how many moles of `HgO` was in the rock?

Answer 1

Is it not spelled `"Xena"`...she was a fit girl, as I recall...

Explanation:

She got `60*g` of mercury metal....this represents a molar quantity of `(60*g)/(200.6*g*mol^-1)=0.299*mol` with RESPECT to the metal. And thus there were `0.299*mol` with respect to mercuric oxide...

`HgO(s) + Delta rarr Hg(l) + 1/2O_2`

You have to heat the oxide fairly fiercley to effect the decomposition. the decomposition of `"cinnabar, mercuric sulfide"`, is much more facile.. What mass of `"mercuric oxide"` was reacted here?

`HgS(s) + Delta rarr Hg(l) + S(s)`